Geomicrobiological study of modern microbialites from Mexico: towards a better understanding of the ancient fossil record

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Benzerara K.

2014-02-01

Full Text Available Microbialites are sedimentary formations that are found throughout the geological record and are usually considered as one of the oldest traces of life on Earth. Although they have been known for more than a century and hold as an emblematic object in Earth Sciences, we yet do not understand in details how they form and how microbial processes impact their chemistry, structure and macroscopic morphology. Here, we show recent advances achieved owing to funding provided by the EPOV program on the formation of modern microbialites in the crater Lake Alchichica (Mexico. We first show that very diverse microbial communities populate these microbialites, including diverse microbial groups able to induce carbonate precipitation. We demonstrate that this microbial diversity can be preserved for several years in laboratory aquaria offering a nice opportunity for future studies to assess the relationships between biodiversity and microbialite formation. We then detail the textural modifications affecting cyanobacterial cells during the first steps of fossilization as captured in Alchichica microbialites. Finally, we report the discovery of a new deepbranching cyanobacterium species, Candidatus Gloeomargarita lithophora, able to form intracellular Ca-, Mg-, Sr- and Ba-rich carbonates and discuss the implications for the interpretation of the fossil record.

'Citizen science' recording of fossils by adapting existing computer-based biodiversity recording tools

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McGowan, Alistair

2014-05-01

Biodiversity recording activities have been greatly enhanced by the emergence of online schemes and smartphone applications for recording and sharing data about a wide variety of flora and fauna. As a palaeobiologist, one of the areas of research I have been heavily involved in is the question of whether the amount of rock available to sample acts as a bias on our estimates of biodiversity through time. Although great progress has been made on this question over the past ten years by a number of researchers, I still think palaeontology has not followed the lead offered by the 'citizen science' revolution in studies of extant biodiversity. By constructing clearly structured surveys with online data collection support, it should be possible to collect field data on the occurrence of fossils at the scale of individual exposures, which are needed to test competing hypotheses about these effects at relatively small spatial scales. Such data collection would be hard to justify for universities and museums with limited personnel but a co-ordinated citizen science programme would be capable of delivering such a programme. Data collection could be based on the MacKinnon's Lists method, used in rapid conservation assessment work. It relies on observers collecting lists of a fixed length (e.g. 10 species long) but what is important is that it focuses on getting observers to ignore sightings of the same species until that list is complete. This overcomes the problem of 'common taxa being commonly recorded' and encourages observers to seek out and identify the rarer taxa. This gives a targeted but finite task. Rather than removing fossils, participants would be encouraged to take photographs to share via a recording website. The success of iSpot, which allows users to upload photos of plants and animals for other users to help with identifications, offers a model for overcoming the problems of identifying fossils, which can often look nothing like the examples illustrated in

Crustaceans from bitumen clast in Carboniferous glacial diamictite extend fossil record of copepods.

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Selden, Paul A; Huys, Rony; Stephenson, Michael H; Heward, Alan P; Taylor, Paul N

2010-08-10

Copepod crustaceans are extremely abundant but, because of their small size and fragility, they fossilize poorly. Their fossil record consists of one Cretaceous (c. 115 Ma) parasite and a few Miocene (c. 14 Ma) fossils. In this paper, we describe abundant crustacean fragments, including copepods, from a single bitumen clast in a glacial diamictite of late Carboniferous age (c. 303 Ma) from eastern Oman. Geochemistry identifies the source of the bitumen as an oilfield some 100-300 km to the southwest, which is consistent with an ice flow direction from glacial striae. The bitumen likely originated as an oil seep into a subglacial lake. This find extends the fossil record of copepods by some 188 Ma, and of free-living forms by 289 Ma. The copepods include evidence of the extant family Canthocamptidae, believed to have colonized fresh water in Pangaea during Carboniferous times.

Methods for the quantitative comparison of molecular estimates of clade age and the fossil record.

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Clarke, Julia A; Boyd, Clint A

2015-01-01

Approaches quantifying the relative congruence, or incongruence, of molecular divergence estimates and the fossil record have been limited. Previously proposed methods are largely node specific, assessing incongruence at particular nodes for which both fossil data and molecular divergence estimates are available. These existing metrics, and other methods that quantify incongruence across topologies including entirely extinct clades, have so far not taken into account uncertainty surrounding both the divergence estimates and the ages of fossils. They have also treated molecular divergence estimates younger than previously assessed fossil minimum estimates of clade age as if they were the same as cases in which they were older. However, these cases are not the same. Recovered divergence dates younger than compared oldest known occurrences require prior hypotheses regarding the phylogenetic position of the compared fossil record and standard assumptions about the relative timing of morphological and molecular change to be incorrect. Older molecular dates, by contrast, are consistent with an incomplete fossil record and do not require prior assessments of the fossil record to be unreliable in some way. Here, we compare previous approaches and introduce two new descriptive metrics. Both metrics explicitly incorporate information on uncertainty by utilizing the 95% confidence intervals on estimated divergence dates and data on stratigraphic uncertainty concerning the age of the compared fossils. Metric scores are maximized when these ranges are overlapping. MDI (minimum divergence incongruence) discriminates between situations where molecular estimates are younger or older than known fossils reporting both absolute fit values and a number score for incompatible nodes. DIG range (divergence implied gap range) allows quantification of the minimum increase in implied missing fossil record induced by enforcing a given set of molecular-based estimates. These metrics are used

Testing New Proxies for Photosymbiosis in the Fossil Record

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Tornabene, C.; Martindale, R. C.; Schaller, M. F.

2015-12-01

Photosymbiosis is a mutualistic relationship that many corals have developed with dinoflagellates called zooxanthellae. The dinoflagellates, of the genus Symbiodinium, photosynthesize and provide corals with most of their energy, while in turn coral hosts live in waters where zooxanthellae have optimal exposure to sunlight. Thanks to this relationship, symbiotic corals calcify faster than non-symbiotic corals. Photosymbiosis is therefore considered the evolutionary innovation that allowed corals to become major reef-builders through geological time.This relationship is extremely difficult to study. Zooxanthellae, which are housed in the coral tissue, are not preserved in fossil coral skeletons, thus determining whether corals had symbionts requires a robust proxy. In order to address this critical question, the goal of this research is to test new proxies for ancient photosymbiosis. Currently the project is focused on assessing the nitrogen (δ15N) isotopes of corals' organic matrices, sensu Muscatine et al. (2005), as well as carbon and oxygen (δ13C, δ18O) isotopes of fossil coral skeletons. Samples from Modern, Pleistocene, Oligocene and Triassic coral skeletons were analyzed to test the validity of these proxies. Coral samples comprise both (interpreted) symbiotic and non-symbiotic fossil corals from the Oligocene and Triassic as well as symbiotic fossil corals from the Modern and Pleistocene to corroborate our findings with the results of Muscatine et al. (2005). Samples were tested for diagenesis through petrographic and scanning electron microscope (SEM) analyses to avoid contamination. Additionally, a novel technique that has not yet been applied to the fossil record was tested. The technique aims to recognize dinosterol, a dinoflagellate biomarker, in both modern and fossil coral samples. The premise of this proxy is that symbiotic corals should contain the dinoflagellate biomarker, whereas those lacking symbionts should lack dinosterol. Results from this

The Completeness of the Fossil Record of Mesozoic Birds: Implications for Early Avian Evolution

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Brocklehurst, Neil; Upchurch, Paul; Mannion, Philip D.; O'Connor, Jingmai

2012-01-01

Many palaeobiological analyses have concluded that modern birds (Neornithes) radiated no earlier than the Maastrichtian, whereas molecular clock studies have argued for a much earlier origination. Here, we assess the quality of the fossil record of Mesozoic avian species, using a recently proposed character completeness metric which calculates the percentage of phylogenetic characters that can be scored for each taxon. Estimates of fossil record quality are plotted against geological time and compared to estimates of species level diversity, sea level, and depositional environment. Geographical controls on the avian fossil record are investigated by comparing the completeness scores of species in different continental regions and latitudinal bins. Avian fossil record quality varies greatly with peaks during the Tithonian-early Berriasian, Aptian, and Coniacian–Santonian, and troughs during the Albian-Turonian and the Maastrichtian. The completeness metric correlates more strongly with a ‘sampling corrected’ residual diversity curve of avian species than with the raw taxic diversity curve, suggesting that the abundance and diversity of birds might influence the probability of high quality specimens being preserved. There is no correlation between avian completeness and sea level, the number of fluviolacustrine localities or a recently constructed character completeness metric of sauropodomorph dinosaurs. Comparisons between the completeness of Mesozoic birds and sauropodomorphs suggest that small delicate vertebrate skeletons are more easily destroyed by taphonomic processes, but more easily preserved whole. Lagerstätten deposits might therefore have a stronger impact on reconstructions of diversity of smaller organisms relative to more robust forms. The relatively poor quality of the avian fossil record in the Late Cretaceous combined with very patchy regional sampling means that it is possible neornithine lineages were present throughout this interval but

Fossil gaps inferred from phylogenies alter the apparent nature of diversification in dragonflies and their relatives

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Nicholson David B

2011-09-01

Full Text Available Abstract Background The fossil record has suggested that clade growth may differ in marine and terrestrial taxa, supporting equilibrial models in the former and expansionist models in the latter. However, incomplete sampling may bias findings based on fossil data alone. To attempt to correct for such bias, we assemble phylogenetic supertrees on one of the oldest clades of insects, the Odonatoidea (dragonflies, damselflies and their extinct relatives, using MRP and MRC. We use the trees to determine when, and in what clades, changes in taxonomic richness have occurred. We then test whether equilibrial or expansionist models are supported by fossil data alone, and whether findings differ when phylogenetic information is used to infer gaps in the fossil record. Results There is broad agreement in family-level relationships between both supertrees, though with some uncertainty along the backbone of the tree regarding dragonflies (Anisoptera. "Anisozygoptera" are shown to be paraphyletic when fossil information is taken into account. In both trees, decreases in net diversification are associated with species-poor extant families (Neopetaliidae, Hemiphlebiidae, and an upshift is associated with Calopterygidae + Polythoridae. When ghost ranges are inferred from the fossil record, many families are shown to have much earlier origination dates. In a phylogenetic context, the number of family-level lineages is shown to be up to twice as high as the fossil record alone suggests through the Cretaceous and Cenozoic, and a logistic increase in richness is detected in contrast to an exponential increase indicated by fossils alone. Conclusions Our analysis supports the notion that taxa, which appear to have diversified exponentially using fossil data, may in fact have diversified more logistically. This in turn suggests that one of the major apparent differences between the marine and terrestrial fossil record may simply be an artifact of incomplete sampling

The Quality of the Fossil Record: Populations, Species, and Communities

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Kidwell, Susan M.; Flessa, Karl W.

Paleontologists have always been concerned about the documentary quality of the fossil record, and this has also become an important issue for biologists, who increasingly look to accumulations of bones, shells, and plant material as possible ways to extend the time-frame of observation on species and community behaviors. Quantitative data on the postmortem behavior of organic remains in modern environments are providing new insights into death and fossil assemblages as sources of biological information. Important findings include: 1. With the exception of a few circumstances, usually recognizable by independent criteria, transport out of the original life habitat affects few individuals. 2. Most species with preservable hard-parts are in fact represented in the local death assemblage, commonly in correct rank importance. Molluscs are the most durable of modern aquatic groups studied so far, and they show highest fidelity to the original community. 3. Time-averaging of remains from successive generations and communities often prevents the detection of short term (seasons, years) variability but provides an excellent record of the natural range of community composition and structure over longer periods. Thus, although a complex array of processes and circumstances influences preservation, death assemblages of resistant skeletal elements are for many major groups good to excellent records of community composition, morphological variation, and environmental and geographic distribution of species, and such assemblages can record dynamics at ecologically and evolutionarily meaningful scales.

The late Paleozoic ecological-evolutionary laboratory, a land-plant fossil record perspective

NARCIS (Netherlands)

Looy, Cindy; Kerp, Hans; Duijnstee, Ivo; DiMichele, Bill

2014-01-01

In this essay we examine the fossil record of land plants, focusing on the late Paleozoic. We explore the nature of this record in terms of what is preserved, where, why and with what biases. And as a consequence, how it can be used to answer questions posed at various spatial and temporal scales,

The avian fossil record in Insular Southeast Asia and its implications for avian biogeography and palaeoecology

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Hanneke J.M. Meijer

2014-03-01

Full Text Available Excavations and studies of existing collections during the last decades have significantly increased the abundance as well as the diversity of the avian fossil record for Insular Southeast Asia. The avian fossil record covers the Eocene through the Holocene, with the majority of bird fossils Pleistocene in age. Fossil bird skeletal remains represent at least 63 species in 54 genera and 27 families, and two ichnospecies are represented by fossil footprints. Birds of prey, owls and swiftlets are common elements. Extinctions seem to have been few, suggesting continuity of avian lineages since at least the Late Pleistocene, although some shifts in species ranges have occurred in response to climatic change. Similarities between the Late Pleistocene avifaunas of Flores and Java suggest a dispersal route across southern Sundaland. Late Pleistocene assemblages of Niah Cave (Borneo and Liang Bua (Flores support the rainforest refugium hypothesis in Southeast Asia as they indicate the persistence of forest cover, at least locally, throughout the Late Pleistocene and Holocene.

Uranium in fossil bones

International Nuclear Information System (INIS)

Koul, S.L.

1978-01-01

An attempt has been made to determine the uranium content and thus the age of certain fossil bones Haritalyangarh (Himachal Pradesh), India. The results indicate that bones rich in apatite are also rich in uranium, and that the radioactivity is due to radionuclides in the uranium series. The larger animals apparently have a higher concentration of uranium than the small. The dating of a fossil jaw (elephant) places it in the Pleistocene. (Auth.)

Children's Ideas about Fossils and Foundational Concepts Related to Fossils

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Borgerding, Lisa A.; Raven, Sara

2018-01-01

Many standards documents and learning progressions recommend evolution learning in elementary grades. Given young children's interest in dinosaurs and other fossils, fossil investigations can provide a rich entry into evolutionary biology for young learners. Educational psychology literature has addressed children's reasoning about foundational…

Early Pliocene anuran fossils from Kanapoi, Kenya, and the first fossil record for the African burrowing frog Hemisus (Neobatrachia: Hemisotidae).

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Delfino, Massimo

2017-07-13

Isolated amphibian bones from the early Pliocene of Kanapoi (West Turkana, Kenya) help to improve the scarce fossil record of the late Neogene and Quaternary amphibians from East Africa. All currently available 579 bones are referable exclusively to the Anura (frogs and toads). More than half of the remains (366) are identified as Hemisus cf. Hemisus marmoratus, an extant species that still inhabits Kenya, but apparently not the northwest of the country and the Turkana area in particular. The rest of the remains are identified simply as Anura indet. because of poor preservation or non congruence with the relatively few African extant taxa whose osteology is known in detail. The Hemisus material represents the first fossil record for Hemisotidae, an endemic African family of peculiar, head-first burrowing frogs, whose sister taxon relationships indicate a divergence from brevicipitids in the Late Cretaceous or early Paleocene. The ecological requirements of extant H. marmoratus suggest that the Kanapoi area surrounding the fluvial and deltaic settings, from where the fossil remains of vertebrates were buried, was likely a grassland or relatively dry, open low tree-shrub savanna. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molecular decay of the tooth gene Enamelin (ENAM mirrors the loss of enamel in the fossil record of placental mammals.

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Robert W Meredith

2009-09-01

Full Text Available Vestigial structures occur at both the anatomical and molecular levels, but studies documenting the co-occurrence of morphological degeneration in the fossil record and molecular decay in the genome are rare. Here, we use morphology, the fossil record, and phylogenetics to predict the occurrence of "molecular fossils" of the enamelin (ENAM gene in four different orders of placental mammals (Tubulidentata, Pholidota, Cetacea, Xenarthra with toothless and/or enamelless taxa. Our results support the "molecular fossil" hypothesis and demonstrate the occurrence of frameshift mutations and/or stop codons in all toothless and enamelless taxa. We then use a novel method based on selection intensity estimates for codons (omega to calculate the timing of iterated enamel loss in the fossil record of aardvarks and pangolins, and further show that the molecular evolutionary history of ENAM predicts the occurrence of enamel in basal representatives of Xenarthra (sloths, anteaters, armadillos even though frameshift mutations are ubiquitous in ENAM sequences of living xenarthrans. The molecular decay of ENAM parallels the morphological degeneration of enamel in the fossil record of placental mammals and provides manifest evidence for the predictive power of Darwin's theory.

Extant-only comparative methods fail to recover the disparity preserved in the bird fossil record.

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Mitchell, Jonathan S

2015-09-01

Most extant species are in clades with poor fossil records, and recent studies of comparative methods show they have low power to infer even highly simplified models of trait evolution without fossil data. Birds are a well-studied radiation, yet their early evolutionary patterns are still contentious. The fossil record suggests that birds underwent a rapid ecological radiation after the end-Cretaceous mass extinction, and several smaller, subsequent radiations. This hypothesized series of repeated radiations from fossil data is difficult to test using extant data alone. By uniting morphological and phylogenetic data on 604 extant genera of birds with morphological data on 58 species of extinct birds from 50 million years ago, the "halfway point" of avian evolution, I have been able to test how well extant-only methods predict the diversity of fossil forms. All extant-only methods underestimate the disparity, although the ratio of within- to between-clade disparity does suggest high early rates. The failure of standard models to predict high early disparity suggests that recent radiations are obscuring deep time patterns in the evolution of birds. Metrics from different models can be used in conjunction to provide more valuable insights than simply finding the model with the highest relative fit. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

Delineating modern variation from extinct morphology in the fossil record using shells of the Eastern Box Turtle (Terrapene carolina)

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2018-01-01

Characterization of morphological variation in the shells of extant Eastern Box Turtles, Terrapene carolina, provides a baseline for comparison to fossil populations. It also provides an example of the difficulties inherent to recognizing intraspecific diversity in the fossil record. The degree to which variation in fossils of T. carolina can be accommodated by extant variation in the species has been disagreed upon for over eighty years. Using morphometric analyses of the carapace, I address the relationship between modern and fossil T. carolina in terms of sexual dimorphism, geographic and subspecific variation, and allometric variation. Modern T. carolina display weak male-biased sexual size dimorphism. Sexual shape dimorphism cannot be reliably detected in the fossil record. Rather than a four-part subspecific division, patterns of geographic variation are more consistent with clinal variation between various regions in the species distribution. Allometric patterns are qualitatively similar to those documented in other emydid turtles and explain a significant amount of shape variation. When allometric patterns are accounted for, Holocene specimens are not significantly different from modern specimens. In contrast, several geologically older specimens have significantly different carapace shape with no modern analogue. Those large, fossilized specimens represent extinct variation occupying novel portions of morphospace. This study highlights the need for additional documentation of modern osteological variation that can be used to test hypotheses of intraspecific evolution in the fossil record. PMID:29513709

The fossil record of turtles in Colombia; a review of the discoveries, research and future challenges

International Nuclear Information System (INIS)

Cadena, Edwin A

2014-01-01

This is a review article on the fossil record of turtles in colombia that includes: the early cretaceous turtles from Zapatoca and Villa de Leyva localities; the giant turtles from the Paleocene Cerrejon and Calenturitas Coal Mines; the early Miocene, earliest record of Chelus from Pubenza, Cundinamarca; the early to late Miocene large podocnemids, chelids and testudinids from Castilletes, Alta Guajira and La Venta; and the small late Pleistocene kinosternids from Pubenza, Cundinamarca. I also discuss here the current gaps in the fossil record of tropical South American turtles, as well as the ongoing research and future projects to be developed in order to understand better the evolutionary history of Colombian turtles.

Radioactivity in fossils at the Hagerman Fossil Beds National Monument.

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Farmer, C Neal; Kathren, Ronald L; Christensen, Craig

2008-08-01

Since 1996, higher than background levels of naturally occurring radioactivity have been documented in both fossil and mineral deposits at Hagerman Fossil Beds National Monument in south-central Idaho. Radioactive fossil sites occur primarily within an elevation zone of 900-1000 m above sea level and are most commonly found associated with ancient river channels filled with sand. Fossils found in clay rich deposits do not exhibit discernable levels of radioactivity. Out of 300 randomly selected fossils, approximately three-fourths exhibit detectable levels of natural radioactivity ranging from 1 to 2 orders of magnitude above ambient background levels when surveyed with a portable hand held Geiger-Muller survey instrument. Mineral deposits in geologic strata also show above ambient background levels of radioactivity. Radiochemical lab analysis has documented the presence of numerous natural radioactive isotopes. It is postulated that ancient groundwater transported radioactive elements through sand bodies containing fossils which precipitated out of solution during the fossilization process. The elevated levels of natural radioactivity in fossils may require special precautions to ensure that exposures to personnel from stored or displayed items are kept as low as reasonably achievable (ALARA).

New Miocene sulid birds from Peru and considerations on their Neogene fossil record in the Eastern Pacific Ocean

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Marcelo Stucchi

2016-06-01

Full Text Available Boobies and gannets (family Sulidae are the most specialized plunge divers among seabirds. Their fossil record along the Pacific coast of South America extends to the early Middle Miocene. Here we describe three new species of sulids: Sula brandi sp. nov., Sula figueroae sp. nov., and Ramphastosula aguirrei sp. nov., from the early Late Miocene of the Pisco Formation (Peru. Two of them are relatives of the living genus Sula, which represents medium and large-sized boobies. A new species of the extinct genus Ramphastosula is also described, adding to the discussion of possible alternative feeding strategies among sulids. The fossil record suggests that sympatric sulids exhibit different body sizes at least since the Oligocene epoch, a strategy related with resource partitioning. Furthermore, we find current analysis and knowledge of the fossil record unsuitable to evaluate properly seabird diversity changes through time.

A rich fossil record yields calibrated phylogeny for Acanthaceae (Lamiales) and evidence for marked biases in timing and directionality of intercontinental disjunctions.

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Tripp, Erin A; McDade, Lucinda A

2014-09-01

More than a decade of phylogenetic research has yielded a well-sampled, strongly supported hypothesis of relationships within the large ( > 4000 species) plant family Acanthaceae. This hypothesis points to intriguing biogeographic patterns and asymmetries in sister clade diversity but, absent a time-calibrated estimate for this evolutionary history, these patterns have remained unexplored. Here, we reconstruct divergence times within Acanthaceae using fossils as calibration points and experimenting with both fossil selection and effects of invoking a maximum age prior related to the origin of Eudicots. Contrary to earlier reports of a paucity of fossils of Lamiales (an order of ∼ 23,000 species that includes Acanthaceae) and to the expectation that a largely herbaceous to soft-wooded and tropical lineage would have few fossils, we recovered 51 reports of fossil Acanthaceae. Rigorous evaluation of these for accurate identification, quality of age assessment and utility in dating yielded eight fossils judged to merit inclusion in analyses. With nearly 10 kb of DNA sequence data, we used two sets of fossils as constraints to reconstruct divergence times. We demonstrate differences in age estimates depending on fossil selection and that enforcement of maximum age priors substantially alters estimated clade ages, especially in analyses that utilize a smaller rather than larger set of fossils. Our results suggest that long-distance dispersal events explain present-day distributions better than do Gondwanan or northern land bridge hypotheses. This biogeographical conclusion is for the most part robust to alternative calibration schemes. Our data support a minimum of 13 Old World (OW) to New World (NW) dispersal events but, intriguingly, only one in the reverse direction. Eleven of these 13 were among Acanthaceae s.s., which comprises > 90% of species diversity in the family. Remarkably, if minimum age estimates approximate true history, these 11 events occurred within

New Eocene Coleoid (Cephalopoda Diversity from Statolith Remains: Taxonomic Assignation, Fossil Record Analysis, and New Data for Calibrating Molecular Phylogenies.

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Pascal Neige

Full Text Available New coleoid cephalopods are described from statolith remains from the Middle Eocene (Middle Lutetian of the Paris Basin. Fifteen fossil statoliths are identified and assigned to the Sepiidae (Sepia boletzkyi sp. nov.,? Sepia pira sp. nov., Loliginidae (Loligo clarkei sp. nov., and Ommastrephidae (genus indet. families. The sediments containing these fossils indicate permanent aquatic settings in the infralittoral domain. These sediments range in age from 46 Mya to 43 Mya. Analysis of the fossil record of statoliths (from findings described here, together with a review of previously published data indicates marked biases in our knowledge. Fossil statoliths are known from as far back as the Early Jurassic (199.3 to 190.8 Mya but surprisingly, to the best of our knowledge, no record occurs in the Cretaceous. This is a "knowledge bias" and clearly calls for further studies. Finally, we attempt to compare findings described here with fossils previously used to constrain divergence and/or diversification ages of some coleoid subclades in molecular phylogenies. This comparison clearly indicates that the new records detailed here will challenge some estimated divergence times of coleoid cephalopod subclades.

New Eocene Coleoid (Cephalopoda) Diversity from Statolith Remains: Taxonomic Assignation, Fossil Record Analysis, and New Data for Calibrating Molecular Phylogenies.

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Neige, Pascal; Lapierre, Hervé; Merle, Didier

2016-01-01

New coleoid cephalopods are described from statolith remains from the Middle Eocene (Middle Lutetian) of the Paris Basin. Fifteen fossil statoliths are identified and assigned to the Sepiidae (Sepia boletzkyi sp. nov.,? Sepia pira sp. nov.), Loliginidae (Loligo clarkei sp. nov.), and Ommastrephidae (genus indet.) families. The sediments containing these fossils indicate permanent aquatic settings in the infralittoral domain. These sediments range in age from 46 Mya to 43 Mya. Analysis of the fossil record of statoliths (from findings described here, together with a review of previously published data) indicates marked biases in our knowledge. Fossil statoliths are known from as far back as the Early Jurassic (199.3 to 190.8 Mya) but surprisingly, to the best of our knowledge, no record occurs in the Cretaceous. This is a "knowledge bias" and clearly calls for further studies. Finally, we attempt to compare findings described here with fossils previously used to constrain divergence and/or diversification ages of some coleoid subclades in molecular phylogenies. This comparison clearly indicates that the new records detailed here will challenge some estimated divergence times of coleoid cephalopod subclades.

Gaps in the Rock and Fossil Records and Implications for the Rate and Mode of Evolution.

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Smith, Grant Sackett

1988-01-01

Examines three types of gaps in the fossil record: real gaps, imaginary gaps, and temporary gaps. Reviews some recent evidence concerning evolution from the paleontological record of microfossils, invertebrates, and vertebrates in order to make some general conclusions regarding the manner in which life evolved on earth. (CW)

Microaerobic steroid biosynthesis and the molecular fossil record of Archean life

OpenAIRE

Waldbauer, Jacob R.; Newman, Dianne K.; Summons, Roger E.

2011-01-01

The power of molecular oxygen to drive many crucial biogeochemical processes, from cellular respiration to rock weathering, makes reconstructing the history of its production and accumulation a first-order question for understanding Earth’s evolution. Among the various geochemical proxies for the presence of O_2 in the environment, molecular fossils offer a unique record of O_2 where it was first produced and consumed by biology: in sunlit aquatic habitats. As steroid biosynthesis requires mo...

Decay of velvet worms (Onychophora), and bias in the fossil record of lobopodians.

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Murdock, Duncan Je; Gabbott, Sarah E; Mayer, Georg; Purnell, Mark A

2014-11-29

Fossil lobopodians, including animals proposed to have close affinity to modern onychophorans, are crucial to understanding the evolution of the panarthropod body plan and the phylum-level relationships between the ecdysozoan groups. Unfortunately, the key features of their anatomy are un-mineralized and subject to biases introduced during death, decay and preservation, yet the extent to which these fossils have been affected by the processes of post-mortem decay is entirely untested. Recent experimental work on chordates has highlighted a profound bias caused by decay, resulting in the erroneous interpretation of badly decayed specimens as primitive members of a clade (stemward slippage). The degree to which this bias affects organisms other than chordates is unknown. Here we use experimental decay of velvet worms (Onychophora) to examine the importance of decay bias in fossil lobopodians. Although we find stemward slippage is not significant in the interpretation of non-mineralized lobopodian fossils, the affect of decay is far from unbiased. Quantitative analysis reveals significant changes in body proportions during decay, a spectrum of decay resistance across anatomical features, and correlated decay of topologically associated characters. These results have significant implications for the interpretation of fossil lobopodian remains, demonstrating that features such as body outline and relative proportions are unreliable for taxonomy or phylogenetic reconstruction, unless decay is taken into account. Similarly, the non-independent loss of characters, due to juxtaposition in the body, during decay has the potential to bias phylogenetic analyses of non-biomineralized fossils. Our results are difficult to reconcile with interpretations of highly decay-prone tissues and structures, such as neural tissue, and complex musculature, in recently described Cambrian lobopodians. More broadly, we hypothesize that stemward slippage is unlikely to be a significant factor

The Evolution of Reproduction within Testudinata as Evidenced by the Fossil Record

Science.gov (United States)

Lawver, Daniel Ryan

Although known from every continent except Antarctica and having a fossil record ranging from the Middle Jurassic to the Pleistocene, fossil turtle eggs are relatively understudied. In this dissertation I describe four fossil specimens, interpret paleoecology and conduct cladistic analyses in order to investigate the evolution of turtle reproduction. Fossil eggshell descriptions primarily involve analysis by scanning electron and polarized light microscopy, as well as cathodoluminescence to determine the degree of diagenetic alteration. Carapace lengths and gas conductance are estimated in order to investigate the ecology of the adults that produced fossil turtle eggs and clutches, as well as their incubation environments, respectively. Cladistic analyses of turtle egg and reproductive characters permit assessment of the usefulness of these characters for determining phylogenetic relationships of fossil specimens and the evolution of reproduction in turtles. Specimens described here include 1) Testudoolithus oosp. from the Late Cretaceous of Madagascar, 2) a clutch of eggs (some containing late stage embryos and at least one exhibiting multilayer eggshell) from the Late Cretaceous Judith River Formation of Montana and named Testudoolithus zelenitskyae oosp. nov., 3) an egg contained within an adult Basilemys nobilis from the Late Cretaceous Kaiparowits Formation of Utah, and 4) a clutch of Meiolania platyceps eggs from the Pleistocene of Lord Howe Island, Australia. Meiolania platyceps eggs are named Testudoolithus lordhowensis oosp. nov. and provide valuable information on the origin of aragonite eggshell composition and nesting behaviors. Cladistic analyses utilizing egg and reproductive characters are rarely performed on taxa outside of Dinosauria. My analyses demonstrate that morphological data produces poorly resolved trees in which only the clades Adocia and Trionychia are resolved and all other turtles form a large polytomy. However, when combined with

A multi-calibrated mitochondrial phylogeny of extant Bovidae (Artiodactyla, Ruminantia) and the importance of the fossil record to systematics.

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Bibi, Faysal

2013-08-08

Molecular phylogenetics has provided unprecedented resolution in the ruminant evolutionary tree. However, molecular age estimates using only one or a few (often misapplied) fossil calibration points have produced a diversity of conflicting ages for important evolutionary events within this clade. I here identify 16 fossil calibration points of relevance to the phylogeny of Bovidae and Ruminantia and use these, individually and together, to construct a dated molecular phylogeny through a reanalysis of the full mitochondrial genome of over 100 ruminant species. The new multi-calibrated tree provides ages that are younger overall than found in previous studies. Among these are young ages for the origin of crown Ruminantia (39.3-28.8 Ma), and crown Bovidae (17.3-15.1 Ma). These are argued to be reasonable hypotheses given that many basal fossils assigned to these taxa may in fact lie on the stem groups leading to the crown clades, thus inflating previous age estimates. Areas of conflict between molecular and fossil dates do persist, however, especially with regard to the base of the rapid Pecoran radiation and the sister relationship of Moschidae to Bovidae. Results of the single-calibrated analyses also show that a very wide range of molecular age estimates are obtainable using different calibration points, and that the choice of calibration point can influence the topology of the resulting tree. Compared to the single-calibrated trees, the multi-calibrated tree exhibits smaller variance in estimated ages and better reflects the fossil record. The use of a large number of vetted fossil calibration points with soft bounds is promoted as a better approach than using just one or a few calibrations, or relying on internal-congruency metrics to discard good fossil data. This study also highlights the importance of considering morphological and ecological characteristics of clades when delimiting higher taxa. I also illustrate how phylogeographic and paleoenvironmental

An early Oligocene fossil demonstrates treeshrews are slowly evolving "living fossils".

Science.gov (United States)

Li, Qiang; Ni, Xijun

2016-01-14

Treeshrews are widely considered a "living model" of an ancestral primate, and have long been called "living fossils". Actual fossils of treeshrews, however, are extremely rare. We report a new fossil species of Ptilocercus treeshrew recovered from the early Oligocene (~34 Ma) of China that represents the oldest definitive fossil record of the crown group of treeshrews and nearly doubles the temporal length of their fossil record. The fossil species is strikingly similar to the living Ptilocercus lowii, a species generally recognized as the most plesiomorphic extant treeshrew. It demonstrates that Ptilocercus treeshrews have undergone little evolutionary change in their morphology since the early Oligocene. Morphological comparisons and phylogenetic analysis support the long-standing idea that Ptilocercus treeshrews are morphologically conservative and have probably retained many characters present in the common stock that gave rise to archontans, which include primates, flying lemurs, plesiadapiforms and treeshrews. This discovery provides an exceptional example of slow morphological evolution in a mammalian group over a period of 34 million years. The persistent and stable tropical environment in Southeast Asia through the Cenozoic likely played a critical role in the survival of such a morphologically conservative lineage.

The first fossil of a bolbitidoid fern belongs to the early-divergent lineages of Elaphoglossum (Dryopteridaceae).

Science.gov (United States)

Lóriga, Josmaily; Schmidt, Alexander R; Moran, Robbin C; Feldberg, Kathrin; Schneider, Harald; Heinrichs, Jochen

2014-09-01

• Closing gaps in the fossil record and elucidating phylogenetic relationships of mostly incomplete fossils are major challenges in the reconstruction of the diversification of fern lineages through time. The cosmopolitan family Dryopteridaceae represents one of the most species-rich families of leptosporangiate ferns, yet its fossil record is sparse and poorly understood. Here, we describe a fern inclusion in Miocene Dominican amber and investigate its relationships to extant Dryopteridaceae.• The morphology of the fossil was compared with descriptions of extant ferns, resulting in it being tentatively assigned to the bolbitidoid fern genus Elaphoglossum. This assignment was confirmed by reconstructing the evolution of the morphological characters preserved in the inclusion on a molecular phylogeny of 158 extant bolbitidoid ferns. To assess the morphology-based assignment of the fossil to Elaphoglossum, we examined DNA-calibrated divergence time estimates against the age of the amber deposits from which it came.• The fossil belongs to Elaphoglossum and is the first of a bolbitidoid fern. Its assignment to a particular section of Elaphoglossum could not be determined; however, sects. Lepidoglossa, Polytrichia, and Setosa can be discounted because the fossil lacks subulate scales or scales with acicular marginal hairs. Thus, the fossil might belong to either sects. Amygdalifolia, Wrightiana, Elaphoglossum, or Squamipedia or to an extinct lineage.• The discovery of a Miocene Elaphoglossum fossil provides remarkable support to current molecular clock-based estimates of the diversification of these ferns. © 2014 Botanical Society of America, Inc.

Biology in the Anthropocene: Challenges and insights from young fossil records

Science.gov (United States)

Kidwell, Susan M.

2015-01-01

With overwhelming evidence of change in habitats, biologists today must assume that few, if any, study areas are natural and that biological variability is superimposed on trends rather than stationary means. Paleobiological data from the youngest sedimentary record, including death assemblages actively accumulating on modern land surfaces and seabeds, provide unique information on the status of present-day species, communities, and biomes over the last few decades to millennia and on their responses to natural and anthropogenic environmental change. Key advances have established the accuracy and resolving power of paleobiological information derived from naturally preserved remains and of proxy evidence for environmental conditions and sample age so that fossil data can both implicate and exonerate human stressors as the drivers of biotic change and permit the effects of multiple stressors to be disentangled. Legacy effects from Industrial and even pre-Industrial anthropogenic extirpations, introductions, (de)nutrification, and habitat conversion commonly emerge as the primary factors underlying the present-day status of populations and communities; within the last 2 million years, climate change has rarely been sufficient to drive major extinction pulses absent other human pressures, which are now manifold. Young fossil records also provide rigorous access to the baseline composition and dynamics of modern-day biota under pre-Industrial conditions, where insights include the millennial-scale persistence of community structures, the dominant role of physical environmental conditions rather than biotic interactions in determining community composition and disassembly, and the existence of naturally alternating states. PMID:25901315

Testing Homogeneity with the Galaxy Fossil Record

CERN Document Server

Hoyle, Ben; Jimenez, Raul; Heavens, Alan; Clarkson, Chris; Maartens, Roy

2013-01-01

Observationally confirming spatial homogeneity on sufficiently large cosmological scales is of importance to test one of the underpinning assumptions of cosmology, and is also imperative for correctly interpreting dark energy. A challenging aspect of this is that homogeneity must be probed inside our past lightcone, while observations take place on the lightcone. The history of star formation rates (SFH) in the galaxy fossil record provides a novel way to do this. We calculate the SFH of stacked Luminous Red Galaxy (LRG) spectra obtained from the Sloan Digital Sky Survey. We divide the LRG sample into 12 equal area contiguous sky patches and 10 redshift slices (0.2

Chemotaxonomy in some Mediterranean plants and implications for fossil biomarker records

Science.gov (United States)

Norström, Elin; Katrantsiotis, Christos; Smittenberg, Rienk H.; Kouli, Katerina

2017-12-01

The increasing utilization of n-alkanes as plant-derived paleo-environmental proxies calls for improved chemotaxonomic control of the modern flora in order to calibrate fossil sediment records to modern analogues. Several recent studies have investigated long-chain n-alkane concentrations and chain-length distributions in species from various vegetation biomes, but up to date, the Mediterranean flora is relatively unexplored in this respect. Here, we analyse the n-alkane concentrations and chain-length distributions in some of the most common species of the modern macchia and phrygana vegetation in south western Peloponnese, Greece. We show that the drought adapted phrygana herbs and shrubs, as well as some of the sclerophyll and gymnosperm macchia components, produce high concentrations of n-alkanes, on average more than double n-alkane production in local wetland reed vegetation. Furthermore, the chain-length distribution in the analysed plants is related to plant functionality, with longer chain lengths associated with higher drought adaptive capacities, probably as a response to long-term evolutionary processes in a moisture limited environment. Furthermore, species with relatively higher average chain lengths (ACL) showed more enriched carbon isotope composition in their tissues (δ13Cplant), suggesting a dual imprint from both physiological and biochemical drought adaptation. The findings have bearings on interpretation of fossil sedimentary biomarker records in the Mediterranean region, which is discussed in relation to a case study from Agios Floros fen, Messenian plain, Peloponnese. The 6000 year long n-alkane record from Agios Floros (ACL, δ13Cwax) is linked to the modern analogue and then evaluated through a comparison with other regional-wide as well as local climate and vegetation proxy-data. The high concentration of long chain n-alkanes in phrygana vegetation suggests a dominating imprint from this vegetation type in sedimentary archives from this

Using extant taxa to inform studies of fossil footprints

Science.gov (United States)

Falkingham, Peter; Gatesy, Stephen

2016-04-01

Attempting to use the fossilized footprints of extinct animals to study their palaeobiology and palaeoecology is notoriously difficult. The inconvenient extinction of the trackmaker makes direct correlation between footprints and foot far from straightforward. However, footprints are the only direct evidence of vertebrate motion recorded in the fossil record, and are potentially a source of data on palaeobiology that cannot be obtained from osteological remains alone. Our interests lie in recovering information about the movements of dinosaurs from their tracks. In particular, the Hitchcock collection of early Jurassic tracks held at the Beneski Museum of Natural History, Amherst, provide a rare look into the 3D form of tracks at and below the surface the animal walked on. Breaking naturally along laminations into 'track books', the specimens present sediment deformation at multiple levels, and in doing so record more of the foot's motion than a single surface might. In order to utilize this rich information source to study the now extinct trackmakers, the process of track formation must be understood at a fundamental level; the interaction of the moving foot and compliant substrate. We used bi-planar X-ray techniques (X-ray Reconstruction of Moving Morphology) to record the limb and foot motions of a Guineafowl traversing both granular and cohesive substrates. This data was supplemented with photogrammetric records of the resultant track surfaces, as well as the motion of metal beads within the sediment, to provide a full experimental dataset of foot and footprint formation. The physical experimental data was used to generate computer simulations of the process using high performance computing and the Discrete Element Method. The resultant simulations showed excellent congruence with reality, and enabled visualization within the sediment volume, and throughout the track-forming process. This physical and virtual experimental set-up has provided major insight into

Fossil evidence for key innovations in the evolution of insect diversity

Science.gov (United States)

Nicholson, David B.; Ross, Andrew J.; Mayhew, Peter J.

2014-01-01

Explaining the taxonomic richness of the insects, comprising over half of all described species, is a major challenge in evolutionary biology. Previously, several evolutionary novelties (key innovations) have been posited to contribute to that richness, including the insect bauplan, wings, wing folding and complete metamorphosis, but evidence over their relative importance and modes of action is sparse and equivocal. Here, a new dataset on the first and last occurrences of fossil hexapod (insects and close relatives) families is used to show that basal families of winged insects (Palaeoptera, e.g. dragonflies) show higher origination and extinction rates in the fossil record than basal wingless groups (Apterygota, e.g. silverfish). Origination and extinction rates were maintained at levels similar to Palaeoptera in the more derived Polyneoptera (e.g. cockroaches) and Paraneoptera (e.g. true bugs), but extinction rates subsequently reduced in the very rich group of insects with complete metamorphosis (Holometabola, e.g. beetles). Holometabola show evidence of a recent slow-down in their high net diversification rate, whereas other winged taxa continue to diversify at constant but low rates. These data suggest that wings and complete metamorphosis have had the most effect on family-level insect macroevolution, and point to specific mechanisms by which they have influenced insect diversity through time. PMID:25165766

Fossil Crinoids

Science.gov (United States)

Hess, Hans; Ausich, William I.; Brett, Carlton E.; Simms, Michael J.

2003-01-01

Crinoids have graced the oceans for more than 500 million years. Among the most attractive fossils, crinoids had a key role in the ecology of marine communities through much of the fossil record, and their remains are prominent rock forming constituents of many limestones. This is the first comprehensive volume to bring together their form and function, classification, evolutionary history, occurrence, preservation and ecology. The main part of the book is devoted to assemblages of intact fossil crinoids, which are described in their geological setting in twenty-three chapters ranging from the Ordovician to the Tertiary. The final chapter deals with living sea lilies and feather stars. The volume is exquisitely illustrated with abundant photographs and line drawings of crinoids from sites around the world. This authoritative account recreates a fascinating picture of fossil crinoids for paleontologists, geologists, evolutionary and marine biologists, ecologists and amateur fossil collectors.

Validation and application of fossil DNA as a recorder of past marine ecosystems and environmental conditions

NARCIS (Netherlands)

Boere, A.C.

2010-01-01

The majority of planktonic species, including those that are informative in the reconstructions of past marine environmental conditions, do not produce diagnostic features (e.g., cysts, spores, or lipid biomarkers) and would therefore escape identification from the fossil record using traditional

The fossil history of pseudoscorpions (Arachnida: Pseudoscorpiones

Directory of Open Access Journals (Sweden)

D. Harms

2017-08-01

Full Text Available Pseudoscorpions, given their resemblance to scorpions, have attracted human attention since the time of Aristotle, although they are much smaller and lack the sting and elongated tail. These arachnids have a long evolutionary history but their origins and phylogenetic affinities are still being debated. Here, we summarise their fossil record based on a comprehensive review of the literature and data contained in other sources. Pseudoscorpions are one of the oldest colonisers of the land, with fossils known since the Middle Devonian (ca. 390 Ma. The only arachnid orders with an older fossil record are scorpions, harvestmen and acariform mites, plus two extinct groups. Pseudoscorpions do not fossilise easily, and records from the Mesozoic and Cenozoic consist almost exclusively of amber inclusions. Most Mesozoic fossils come from Archingeay and Burmese ambers (Late Cretaceous and those from the Cenozoic are primarily from Eocene Baltic amber, although additional fossils from, for example, Miocene Dominican and Mexican ambers, are known. Overall, 16 of the 26 families of living pseudoscorpions have been documented from fossils and 49 currently valid species are recognised in the literature. Pseudoscorpions represent a case of morphological stasis and even the Devonian fossils look rather modern. Indeed, most amber fossils are comparable to Recent groups despite a major gap in the fossil record of almost 250 Myr. Baltic amber inclusions indicate palaeofauna inhabiting much warmer climates than today and point to climatic shifts in central Europe since the Eocene. They also indicate that some groups (e.g. Feaellidae and Pseudogarypidae had much wider Eocene distributions. Their present-day occurrence is relictual and highlights past extinction events. Faunas from younger tropical amber deposits (e.g. Dominican and Mexican amber are comparable to Recent ones. Generally, there is a strong bias in the amber record towards groups that live under tree

The fossil record of turtles in colombia; a review of the discoveries research and future challenges

OpenAIRE

Cadena Rueda, Edwin Alberto

2014-01-01

This is a review article on the fossil record of turtles in Colombia that includes: the early Cretaceous turtles from Zapatocaand Villa de Leyva localities; the giant turtles from the Paleocene Cerrejón and Calenturitas Coal Mines; the early Miocene,earliest record of Chelus from Pubenza, Cundinamarca; the early to late Miocene large podocnemids, chelids and testudinidsfrom Castilletes, Alta Guajira and La Venta; and the small late Pleistocene kinosternids from Pubenza, Cundinamarca. I alsodi...

Old stellar populations how to study the fossil record of galaxy formation

CERN Document Server

Cassisi, Santi

2013-01-01

The book discusses the theoretical path to decoding the information gathered from observations of old stellar systems. It focuses on old stellar systems because these are the fossil record of galaxy formation and provide invaluable information ont he evolution of cosmic structures and the universe as a whole. The aim is to present results obtained in the past few years for theoretical developments in low mass star research and in advances in our knowledge of the evolution of old stellar systems. A particularly representative case is the recent discovery of multiple stellar populations in galac

Discovery of the fossil otter Enhydritherium terraenovae (Carnivora, Mammalia) in Mexico reconciles a palaeozoogeographic mystery.

Science.gov (United States)

Tseng, Z Jack; Pacheco-Castro, Adolfo; Carranza-Castañeda, Oscar; Aranda-Gómez, José Jorge; Wang, Xiaoming; Troncoso, Hilda

2017-06-01

The North American fossil otter Enhydritherium terraenovae is thought to be partially convergent in ecological niche with the living sea otter Enhydra lutris , both having low-crowned crushing teeth and a close association with marine environments. Fossil records of Enhydritherium are found in mostly marginal marine deposits in California and Florida; despite presence of very rich records of fossil terrestrial mammals in contemporaneous localities inland, no Enhydritherium fossils are hitherto known in interior North America. Here we report the first occurrence of Enhydritherium outside of Florida and California, in a land-locked terrestrial mammal fauna of the upper Miocene deposits of Juchipila Basin, Zacatecas State, Mexico. This new occurrence of Enhydritherium is at least 200 km from the modern Pacific coastline, and nearly 600 km from the Gulf of Mexico. Besides providing further evidence that Enhydritherium was not dependent on coastal marine environments as originally interpreted, this discovery leads us to propose a new east-to-west dispersal route between the Florida and California Enhydritherium populations through central Mexico. The proximity of the fossil locality to nearby populations of modern neotropical otters Lontra longicaudis suggests that trans-Mexican freshwater corridors for vertebrate species in riparian habitats may have persisted for a prolonged period of time, pre-dating the Great American Biotic Interchange. © 2017 The Author(s).

Caught in the act: the first record of copulating fossil vertebrates.

Science.gov (United States)

Joyce, Walter G; Micklich, Norbert; Schaal, Stephan F K; Scheyer, Torsten M

2012-10-23

The behaviour of fossil organisms can typically be inferred only indirectly, but rare fossil finds can provide surprising insights. Here, we report from the Eocene Messel Pit Fossil Site between Darmstadt and Frankfurt, Germany numerous pairs of the fossil carettochelyid turtle Allaeochelys crassesculpta that represent for the first time among fossil vertebrates couples that perished during copulation. Females of this taxon can be distinguished from males by their relatively shorter tails and development of plastral kinesis. The preservation of mating pairs has important taphonomic implications for the Messel Pit Fossil Site, as it is unlikely that the turtles would mate in poisonous surface waters. Instead, the turtles initiated copulation in habitable surface waters, but perished when their skin absorbed poisons while sinking into toxic layers. The mating pairs from Messel are therefore more consistent with a stratified, volcanic maar lake with inhabitable surface waters and a deadly abyss.

Systematics, phylogeny, and taphonomy of ghost shrimps (Decapoda): a perspective from the fossil record

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Klompmaker, Adiël A.

2016-01-01

Ghost shrimps of Callianassidae and Ctenochelidae are soft-bodied, usually heterochelous decapods representing major bioturbators of muddy and sandy (sub)marine substrates. Ghost shrimps have a robust fossil record spanning from the Early Cretaceous (~ 133 Ma) to the Holocene and their remains are present in most assemblages of Cenozoic decapod crustaceans. Their taxonomic interpretation is in flux, mainly because the generic assignment is hindered by their insufficient preservation and disagreement in the biological classification. Furthermore, numerous taxa are incorrectly classified within the catch-all taxon Callianassa. To show the historical patterns in describing fossil ghost shrimps and to evaluate taphonomic aspects influencing the attribution of ghost shrimp remains to higher level taxa, a database of all fossil species treated at some time as belonging to the group has been compiled: 250 / 274 species are considered valid ghost shrimp taxa herein. More than half of these taxa (160 species, 58.4%) are known only from distal cheliped elements, i.e., dactylus and / or propodus, due to the more calcified cuticle locally. Rarely, ghost shrimps are preserved in situ in burrows or in direct association with them, and several previously unpublished occurrences are reported herein. For generic assignment, fossil material should be compared to living species because many of them have modern relatives. Heterochely, intraspecific variation, ontogenetic changes and sexual dimorphism are all factors that have to be taken into account when working with fossil ghost shrimps. Distal elements are usually more variable than proximal ones. Preliminary results suggest that the ghost shrimp clade emerged not before the Hauterivian (~ 133 Ma). The divergence of Ctenochelidae and Paracalliacinae is estimated to occur within the interval of Hauterivian to Albian (133–100 Ma). Callichirinae and Eucalliacinae likely diverged later during the Late Cretaceous (100–66 Ma

The fossil record, function, and possible origins of shell color patterns in Paleozoic marine invertebrates

Energy Technology Data Exchange (ETDEWEB)

Kobluk, D.R. (Univ. of Toronto, Ontario (Canada)); Mapes, R.H. (Ohio Univ., Athens (USA))

1989-02-01

Fossil invertebrate shells and carapaces displaying preserved original color patterns are among the rarest fossils. The fossil record of color patterns extends into the Middle Cambrian where the trilobite Anomocare displays a fan-like array of stripes on the pygidium. About 180 Paleozic genera are known with patterns, including trilobites, cephalopods, gastropods, brachiopods, bivalves, crinoids, and crustaceans. Based upon an analysis of these taxa, it appears that patterns and pigments in middle and late Paleozoic invertebrates may have served several functions such as warning displays, light screening, camouflage, or waste disposal. However, the presence of color patterns in fossil invertebrates in the early Paleozoic may have developed prior to the evolution of vision sufficiently sophisticated to see them. This suggests that camouflage and warning displays were not the original functions of color patterns, and that in the earliest Paleozoic they may not have been functional. The authors propose a hypothesis that involves three developmental phases in the evolution of invertebrate color patterns: (1) the incorporation of metabolic by-products, perhaps some pigmented and some not pigmented, into shells and carapaces as a means of disposal of dietary or metabolic wastes, (2) use of these pigments and patterns as an environmental adaptation, such as light screening, and (3) display during and following the evolution of vision in predators sufficiently sophisticated to see the patterns.

Fossil Coral Records of ENSO during the Last Glacial Period

Science.gov (United States)

Partin, J. W.; Taylor, F. W.; Shen, C. C.; Edwards, R. L.; Quinn, T. M.; DiNezro, P.

2017-12-01

Only a handful of paleoclimate records exist that can resolve interannual changes, and hence El Nino/Southern Oscillation (ENSO) variability, during the last glacial period, a time of altered mean climate. The few existing data suggest reduced ENSO variability compared to the Holocene, possibly due to a weaker zonal sea surface temperature gradient across the tropical Pacific and/or a deeper thermocline in the eastern tropical Pacific. Our goal is to add crucial data to this extremely limited subset using sub-annually resolved fossil corals that grew during this time period to reconstruct ENSO. We seek to recover fossil corals from Vanuatu, SW Pacific (16°S, 167°E) with the objective of using coral δ18O to reconstruct changes in the ENSO during and near the Last Glacial Maximum (LGM). Modern δ18O coral records from Vanuatu show a high degree of skill in capturing ENSO variability, making it a suitable site for reconstructing ENSO variability. We have custom designed and are building a drill system that can rapidly core many 0-25 m holes resulting in much more meters of penetration than achieved by previous land-based reef drilling. As the new drill system is extremely portable and can be quickly relocated by workers without landing craft or vehicles, it is time and cost efficient. Because the proposed drilling sites have uplifted extremely fast, 7 mm/year, the LGM shoreline has been raised from 120-140 m depth to within a depth range of 10 below to 20 m above present sea level. This enables all the drilling to be within the time range of interest ( 15-25 ka). A last advantage is that the LGM corals either are still submersed in seawater or emerged only within the last 2000 years at the uplift rate of 7 mm/yr. This greatly reduces the chances of disruption of the original climate signal because sea water is less diagenetically damaging than meteoric water in the mixed, phreatic, or vadose zones. LGM coral records will enable us to compare the proxy variability

Fruits and wood of Parinari from the early Miocene of Panama and the fossil record of Chrysobalanaceae.

Science.gov (United States)

Jud, Nathan A; Nelson, Chris W; Herrera, Fabiany

2016-02-01

Chrysobalanaceae are woody plants with over 500 species in 20 genera. They are among the most common trees in tropical forests, but a sparse fossil record has limited our ability to test evolutionary and biogeographic hypotheses, and several previous reports of Chrysobalanaceae megafossils are doubtful. We prepared fossil endocarps and wood collected from the lower Miocene beds along the Panama Canal using the cellulose acetate peel technique and examined them using light microscopy. We compared the fossil endocarps with previously published fossils and with fruits from herbarium specimens. We compared the fossil wood with photographs and descriptions of extant species. Parinari endocarps can be distinguished from other genera within Chrysobalanaceae by a suite of features, i.e., thick wall, a secondary septum, seminal cavities lined with dense, woolly trichomes, and two ovate to lingulate basal germination plugs. Fossil endocarps from the Cucaracha, Culebra, and La Boca Formations confirm that Parinari was present in the neotropics by the early Miocene. The earliest unequivocal evidence of crown-group Chrysobalanaceae is late Oligocene-early Miocene, and the genus Parinari was distinct by at least 19 million years ago. Parinari and other Chrysobalanaceae likely reached the neotropics via long-distance dispersal rather than vicariance. The presence of Parinari in the Cucaracha flora supports the interpretation of a riparian, moist tropical forest environment. Parinari was probably a canopy-dominant tree in the Cucaracha forest and took advantage of the local megafauna for seed dispersal. © 2016 Botanical Society of America.

The celestial factor and the formula to explain or predict all extinctions of the fossil record

NARCIS (Netherlands)

Elewa, A.M.T.

2012-01-01

In reality there are various kinds of explanations for each type of extinction. This paper introduces a new theory to explain and to estimate the size and frequency of all extinctions over the entire period of 600 my of the fossil record. The central point was the search for a common pattern and

High-resolution δ13C record of fossil wood and bulk organic matter from a deep Oligocene lacustrine succession, Bach Long Vi Island, Vietnam

Science.gov (United States)

Rizzi, M.; Schovsbo, N. H.; Fyhn, M. B. W.; Korte, C.

2017-12-01

We present a high-resolution stable isotope record based on bulk organic matter (δ13Corg) and fossil wood (δ13Cwood) originating from Oligocene deep lacustrine sediments cored on the Bach Long Vi Island, northern Gulf of Tonkin, offshore Vietnam. The sediments are exceptionally well preserved. They are thus excellently suited for a detailed stratigraphical analysis of the stable isotope record and as proxy for environmental and climatic changes within this period. The sediments were deposited in rapid subsiding, narrow and elongated fault-bound graben (Fyhn and Phach, 2015) and are represented by deep pelagic lacustrine organic-rich mud interrupted by numerous density-flow deposits (Hovikoski et al., 2016). The density-flow deposits contain abundant fragments of fossil wood. Therefore it was possible to obtain 262 coalified wood fragments together with 1063 bulk organic samples throughout the span of the core. This allowed to establish a high resolution stable C isotope record (δ13Corg and δ13Cwood). In addition 2464 handheld XRF determinations were carried out to further characterize the depositional environment (Rizzi et al., 2017). The organic carbon isotope trend from the 500 m core succession provides insight into the palaeoenvironmental changes of the lake during the Oligocene. Both, global and local factors control the δ13C variations. The aim of the study is to obtain pure global δ13Corg and δ13Cwood signals that would allow comparison of the studied sediments with coeval syn-rift successions in the South China Sea region and other parts of the world. [1] Fyhn and Phach (2015) Tectonics, 34(2): 290-312. [2] Hovikoski et al. (2016) Journal of Sedimentary Research, 86(8): 982-1007. [3] Rizzi et al. (2017) EGU General Assembly Abstract EGU 2017-17584.

Sequences, stratigraphy and scenarios: what can we say about the fossil record of the earliest tetrapods?

Science.gov (United States)

Friedman, Matt; Brazeau, Martin D

2011-02-07

Past research on the emergence of digit-bearing tetrapods has led to the widely accepted premise that this important evolutionary event occurred during the Late Devonian. The discovery of convincing digit-bearing tetrapod trackways of early Middle Devonian age in Poland has upset this orthodoxy, indicating that current scenarios which link the timing of the origin of digited tetrapods to specific events in Earth history are likely to be in error. Inspired by this find, we examine the fossil record of early digit-bearing tetrapods and their closest fish-like relatives from a statistical standpoint. We find that the Polish trackways force a substantial reconsideration of the nature of the early tetrapod record when only body fossils are considered. However, the effect is less drastic (and often not statistically significant) when other reliably dated trackways that were previously considered anachronistic are taken into account. Using two approaches, we find that 95 per cent credible and confidence intervals for the origin of digit-bearing tetrapods extend into the Early Devonian and beyond, spanning late Emsian to mid Ludlow. For biologically realistic diversity models, estimated genus-level preservation rates for Devonian digited tetrapods and their relatives range from 0.025 to 0.073 per lineage-million years, an order of magnitude lower than species-level rates for groups typically considered to have dense records. Available fossils of early digited tetrapods and their immediate relatives are adequate for documenting large-scale patterns of character acquisition associated with the origin of terrestriality, but low preservation rates coupled with clear geographical and stratigraphic sampling biases caution against building scenarios for the origin of digits and terrestrialization tied to the provenance of particular specimens or faunas.

Direct and indirect fossil records of megachilid bees from the Paleogene of Central Europe (Hymenoptera: Megachilidae)

Science.gov (United States)

Wedmann, Sonja; Wappler, Torsten; Engel, Michael S.

2009-06-01

Aside from pollen and nectar, bees of the subfamily Megachilinae are closely associated with plants as a source of materials for nest construction. Megachilines use resins, masticated leaves, trichomes and other plant materials sometimes along with mud to construct nests in cavities or in soil. Among these, the leafcutter bees ( Megachile s.l.) are the most famous for their behaviour to line their brood cells with discs cut from various plants. We report on fossil records of one body fossil of a new non-leafcutting megachiline and of 12 leafcuttings from three European sites—Eckfeld and Messel, both in Germany (Eocene), and Menat, France (Paleocene). The excisions include the currently earliest record of probable Megachile activity and suggest the presence of such bees in the Paleocene European fauna. Comparison with extant leafcuttings permits the interpretation of a minimal number of species that produced these excisions. The wide range of size for the leafcuttings indirectly might suggest at least two species of Megachile for the fauna of Messel in addition to the other megachiline bee described here. The presence of several cuttings on most leaves from Eckfeld implies that the preferential foraging behaviour of extant Megachile arose early in megachiline evolution. These results demonstrate that combined investigation of body and trace fossils complement each other in understanding past biodiversity, the latter permitting the detection of taxa not otherwise directly sampled and inferences on behavioural evolution.

Extending the fossil record of Polytrichaceae: Early Cretaceous Meantoinea alophosioides gen. et sp. nov., permineralized gametophytes with gemma cups from Vancouver Island.

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Bippus, Alexander C; Stockey, Ruth A; Rothwell, Gar W; Tomescu, Alexandru M F

2017-04-01

Diverse in modern ecosystems, mosses are dramatically underrepresented in the fossil record. Furthermore, most pre-Cenozoic mosses are known only from compression fossils, lacking detailed anatomical information. When preserved, anatomy vastly improves resolution in the systematic placement of fossils. Lower Cretaceous deposits at Apple Bay (Vancouver Island, British Columbia, Canada) contain a diverse anatomically preserved flora that includes numerous bryophytes, many of which have yet to be characterized. Among them is a polytrichaceous moss that is described here. Fossil moss gametophytes preserved in four carbonate concretions were studied in serial sections prepared using the cellulose acetate peel technique. We describe Meantoinea alophosioides gen. et sp. nov., a polytrichaceous moss with terminal gemma cups containing stalked, lenticular gemmae. Leaves with characteristic costal anatomy, differentiated into sheathing base and free lamina and bearing photosynthetic lamellae, along with a conducting strand in the stem, place Meantoinea in family Polytrichaceae. The bistratose leaf lamina with an adaxial layer of mamillose cells, short photosynthetic lamellae restricted to the costa, and presence of gemma cups indicate affinities with basal members of the Polytrichaceae, such as Lyellia , Bartramiopsis , and Alophosia . Meantoinea alophosioides enriches the documented moss diversity of an already-diverse Early Cretaceous plant fossil assemblage. This is the third moss described from the Apple Bay plant fossil assemblage and represents the first occurrence of gemma cups in a fossil moss. It is also the oldest unequivocal record of Polytrichaceae, providing a hard minimum age for the group of 136 million years. © 2017 Botanical Society of America.

The completeness of the fossil record of plesiosaurs, marine reptiles from the Mesozoic

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Samuel L. Tutin

2017-09-01

Full Text Available Plesiosaurs were a highly successful group of marine reptiles occurring worldwide in the Jurassic and Cretaceous, but to date few studies have focused on their preservation through time. Here, we conduct the first detailed assessment of the quality of the plesiosaur fossil record. Data was compiled for 178 specimens representing 114 valid species. For each species we calculated the character completeness metric (CCM: percentage of phylogenetic characters from a cladistic dataset that can be scored for that species and the skeletal completeness metric (SCM: percentage of the overall skeleton that is preserved for that species. Average CCM and SCM values were calculated for individual geological stages. A strong significant positive correlation was recovered between CCM and SCM, suggesting that the two metrics are recording the same signal, at least for this clade. Although a significant correlation between changes in sea level and changes in plesiosaur completeness was not recovered, an underlying negative relationship may be present but obscured by poorly sampled time bins. Plesiosaur completeness though time is not significantly correlated with that for contemporary terrestrial groups (sauropods, pterosaurs, birds, but is significantly correlated with that for ichthyosaurs, suggesting common controls on skeletal preservation in the marine realm. Significantly higher median completeness values in plesiosaurs and ichthyosaurs than in contemporary terrestrial groups support the hypothesis that the marine tetrapod fossil record is more complete than that of terrestrial tetrapods. A collector’s curve for plesiosaurs shows a generally slow constant rate of discovery from the latter part of the 19th century until the 1990s, at which point the rate of discovery increased substantially and shows no sign of slowing. A significant but very weak negative correlation between SCM and the year in which a taxon was named suggests a weak tendency for more

The completeness of the fossil record of plesiosaurs, marine reptiles from the Mesozoic.

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Tutin, Samuel L; Butler, Richard J

2017-01-01

Plesiosaurs were a highly successful group of marine reptiles occurring worldwide in the Jurassic and Cretaceous, but to date few studies have focused on their preservation through time. Here, we conduct the first detailed assessment of the quality of the plesiosaur fossil record. Data was compiled for 178 specimens representing 114 valid species. For each species we calculated the character completeness metric (CCM: percentage of phylogenetic characters from a cladistic dataset that can be scored for that species) and the skeletal completeness metric (SCM: percentage of the overall skeleton that is preserved for that species). Average CCM and SCM values were calculated for individual geological stages. A strong significant positive correlation was recovered between CCM and SCM, suggesting that the two metrics are recording the same signal, at least for this clade. Although a significant correlation between changes in sea level and changes in plesiosaur completeness was not recovered, an underlying negative relationship may be present but obscured by poorly sampled time bins. Plesiosaur completeness though time is not significantly correlated with that for contemporary terrestrial groups (sauropods, pterosaurs, birds), but is significantly correlated with that for ichthyosaurs, suggesting common controls on skeletal preservation in the marine realm. Significantly higher median completeness values in plesiosaurs and ichthyosaurs than in contemporary terrestrial groups support the hypothesis that the marine tetrapod fossil record is more complete than that of terrestrial tetrapods. A collector's curve for plesiosaurs shows a generally slow constant rate of discovery from the latter part of the 19 th century until the 1990s, at which point the rate of discovery increased substantially and shows no sign of slowing. A significant but very weak negative correlation between SCM and the year in which a taxon was named suggests a weak tendency for more recently named

The fossil record as a tool in cyclo stratigraphy: the incidence of Milankovitch-scale palaeoenvironmental changes on palaeocommunities

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Rodriguez-Tovar, F. J.

2013-06-01

Cyclo stratigraphic analysis at the Milankovitch scale has to date mainly been approached through the sedimentary record, although palaeontological data (the fossil record) is known to provide useful evidence of orbital-scale cycles of precession, obliquity and eccentricity. Orbit ally induced marine and terrestrial palaeoenvironmental changes determine variable responses on the part of the resident communities. Aside from the disruption of communities, complex evolutionary responses including stasis, speciation and extinction phenomena may take place. Cyclic variations in the marine past-biota at the community level, or in some particular taxa, have often been associated with orbit ally induced changes in palaeoenvironmental parameters. Cyclo stratigraphic research into foraminifera, radiol aria and nanno fossil data, mainly from Cretaceous sediments, may contribute significantly to our understanding of the planktonic community's response, whereas the response of the benthic community, deriving mainly from benthic foraminifera and trace fossils, has been studied to a lesser extent. Recognition of Milankovitch cycles from terrestrial palaeocommunities is relatively scarce and based mainly on the study of Pliocene-Miocene pollen assemblages. Astronomical forced climate changes determine well known variations in the distribution of terrestrial vegetation, but can also affect the terrestrial animal community, including hominid populations (migration, dispersion and colonisation). (Author)

First fossil insectivores from Flores

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Hoek Ostende, van den L.W.; Berch, van der G.; Awe Due, R.

2006-01-01

The hominid bearing strata from the Liang Bua cave on Flores have yielded a large amount of microvertebrate remains. Among these are three mandibles of shrews, the first record of fossil insectivores from the island. The fossils, representing two different species, are not referable to any of the

Testing the Molecular Clock Using the Best Fossil Record: Case Studies from the Planktic Foraminifera

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Steel, B. A.; Kucera, M.; Darling, K.

2004-12-01

Criticism of molecular clock studies often centres on inadequate calibration and a perceived lack of correlation between reproductive isolation and recognisable morphological evolution. Since many major groups (e.g. birds, mammals, reptiles) have a poor fossil record, it is often difficult to test and refute these limitations. Planktic foraminifera represent an exception to this rule. Deep-sea sediments are super-abundant in foraminifera, and large numbers of specimens and occurrences are easily garnered from Ocean Drilling Programme cores. Planktic foraminifera therefore represent an ideal model group with which to test and refine molecular clock studies. Since the 1990AƒAøAøâ_sA¬Aøâ_zAøs, genetic sequences (principally 18S r-RNA) have been extracted from living planktic foraminifera, and a large genetic library has developed. Our study attempts to contextualise and test molecular data, particularly AƒAøAøâ_sA¬Agenetic studies have suggested that these two AƒAøAøâ_sA¬A<Å"super-speciesAƒAøAøâ_sA¬Aøâ_zAø in fact consist of a number of isolated forms, with contrasting ecologies and longevities, which in Recent and sub-Recent sediments can be distinguished either on the basis of pore ultrastructure (Gl. siphonifera) or test colouration (Gs. ruber). In both cases, molecular clock estimates are indicative of ancient (7-11 Ma) intra-species cryptic divergences, which seem to be considerably older than fossil dates. In particular, the calculated molecular split between the two forms of Gs. ruber (AƒAøAøâ_sA¬A<Å"whiteAƒAøAøâ_sA¬Aøâ_zAø and AƒAøAøâ_sA¬A<Å"pinkAƒAøAøâ_sA¬Aøâ_zAø) of around 11 Ma is considerably discordant with the fossil date of around 0.7 Ma. At first glance, this may appear to be a classic case of molecular over-estimation, often a feature of clock models, especially where, as in the foraminifera, substitution rates may vary widely. However, there is good reason to suspect that fossil range of the

A fossils detector

International Nuclear Information System (INIS)

Buffetaut, E.

1998-01-01

Because fossil bones are often rich in uraninite they can be detected using a portable gamma-ray detector run over the prospected site. Zones with higher radioactivity are possible accumulations of bones or skeletons. This method invented by R. Jones from the University of Utah (Salt Lake City, USA) has been successfully used in the field and led to the discovery of new dinosaur skeletons. Short paper. (J.S.)

The taphonomy of unmineralised Palaeozoic fossils preserved as siliciclastic moulds and casts, and their utility in assessing the interaction between environmental change and the fossil record

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MacGabhann, Breandán; Schiffbauer, James; Hagadorn, James; Van Roy, Peter; Lynch, Edward; Morrsion, Liam; Murray, John

2015-04-01

biopolymers, and that these tissues were preferentially fossilised by the formation of an early diagenic mould directly on the organic surfaces. Excess divalent iron ions, produced during decay of more labile tissues by means of bacterial iron reduction, would have adsorbed to anionic functional groups in the biopolymeric tissues. This would have provided a ready substrate for the formation and growth of such an early diagenic mineralised mould, including aluminosilicate minerals produced via reaction with seawater silica and metal ions, and iron sulphide minerals produced via reaction with hydrogen sulphide and free sulphur produced from seawater sulphate through bacterial sulphate reduction associated with further decay. Subsequent weathering would have oxidised such iron sulphides to oxides and oxyhydroxides. This taphonomic model supports the lack of utility of the eldonid palaeobiological record in analysing environmental influence on biological communities, due to the lack of preservation of key anatomical components. However, it also suggests that the very occurrence of fossils preserved in this style is dependent on extrinsic palaeoenvironmental factors - including pH, Eh, and the concentration of other ions in the contemporaneous seawater. Analyses of the distribution of fossils preserved in this style may therefore provide information on ambient conditions which may have affected the distribution of contemporaneous mineralised fossils, potentially allowing a more complete analysis of the effects of palaeoenvironmental change on fossil ecosystems.

Fossil evidence of the zygomycetous fungi

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Krings, M.; Taylor, T.N.; Dotzler, N.

2013-01-01

Molecular clock data indicate that the first zygomycetous fungi occurred on Earth during the Precambrian, however, fossil evidence of these organisms has been slow to accumulate. In this paper, the fossil record of the zygomycetous fungi is compiled, with a focus on structurally preserved

Review of the fossil matamata turtles: earliest well-dated record and hypotheses on the origin of their present geographical distribution

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Ferreira, Gabriel S.; Rincón, Ascanio D.; Solórzano, Andrés; Langer, Max C.

2016-04-01

The matamata ( Chelus fimbriatus) is a highly aquatic chelid turtle known exclusively from northern South America. Due to its extremely modified morphology, it is well circumscribed among living taxa, but that is not the case of the two extinct species ascribed to the taxon, Chelus colombianus and Chelus lewisi. These were originally described for the Miocene of Colombia and Venezuela, respectively, and are known mostly from post-cranial material. Few traits have been considered diagnostic for these fossil taxa, and their shared geographic and temporal distributions raise doubts about their distinctiveness. Here, we describe new turtle remains from the early Miocene Castillo Formation, at Cerro la Cruz, northwestern Venezuela, assigning them to C. colombianus. We also review the taxonomy and diagnostic features of the fossil species of Chelus, comparing them with the variation recognized within C. fimbriatus. All alleged differences between the fossil Chelus species were found in our sample of the extant species, and may represent intraspecific variation of a single fossil species. Further, we reviewed the fossil record of Chelus spp. and proposed a paleobiogeographic hypothesis to explain its present geographic range.

Evolutionary History of the Asian Horned Frogs (Megophryinae): Integrative Approaches to Timetree Dating in the Absence of a Fossil Record.

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Mahony, Stephen; Foley, Nicole M; Biju, S D; Teeling, Emma C

2017-03-01

Molecular dating studies typically need fossils to calibrate the analyses. Unfortunately, the fossil record is extremely poor or presently nonexistent for many species groups, rendering such dating analysis difficult. One such group is the Asian horned frogs (Megophryinae). Sampling all generic nomina, we combined a novel ∼5 kb dataset composed of four nuclear and three mitochondrial gene fragments to produce a robust phylogeny, with an extensive external morphological study to produce a working taxonomy for the group. Expanding the molecular dataset to include out-groups of fossil-represented ancestral anuran families, we compared the priorless RelTime dating method with the widely used prior-based Bayesian timetree method, MCMCtree, utilizing a novel combination of fossil priors for anuran phylogenetic dating. The phylogeny was then subjected to ancestral phylogeographic analyses, and dating estimates were compared with likely biogeographic vicariant events. Phylogenetic analyses demonstrated that previously proposed systematic hypotheses were incorrect due to the paraphyly of genera. Molecular phylogenetic, morphological, and timetree results support the recognition of Megophryinae as a single genus, Megophrys, with a subgenus level classification. Timetree results using RelTime better corresponded with the known fossil record for the out-group anuran tree. For the priorless in-group, it also outperformed MCMCtree when node date estimates were compared with likely influential historical biogeographic events, providing novel insights into the evolutionary history of this pan-Asian anuran group. Given a relatively small molecular dataset, and limited prior knowledge, this study demonstrates that the computationally rapid RelTime dating tool may outperform more popular and complex prior reliant timetree methodologies. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For

First direct evidence of a vertebrate three-level trophic chain in the fossil record.

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Kriwet, Jürgen; Witzmann, Florian; Klug, Stefanie; Heidtke, Ulrich H J

2008-01-22

We describe the first known occurrence of a Permian shark specimen preserving two temnospondyl amphibians in its digestive tract as well as the remains of an acanthodian fish, which was ingested by one of the temnospondyls. This exceptional find provides for the first time direct evidence of a vertebrate three-level food chain in the fossil record with the simultaneous preservation of three trophic levels. Our analysis shows that small-sized Lower Permian xenacanthid sharks of the genus Triodus preyed on larval piscivorous amphibians. The recorded trophic interaction can be explained by the adaptation of certain xenacanthids to fully freshwater environments and the fact that in these same environments, large temnospondyls occupied the niche of modern crocodiles. This unique faunal association has not been documented after the Permian and Triassic. Therefore, this Palaeozoic three-level food chain provides strong and independent support for changes in aquatic trophic chain structures through time.

Primate diversification inferred from phylogenies and fossils.

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Herrera, James P

2017-12-01

Biodiversity arises from the balance between speciation and extinction. Fossils record the origins and disappearance of organisms, and the branching patterns of molecular phylogenies allow estimation of speciation and extinction rates, but the patterns of diversification are frequently incongruent between these two data sources. I tested two hypotheses about the diversification of primates based on ∼600 fossil species and 90% complete phylogenies of living species: (1) diversification rates increased through time; (2) a significant extinction event occurred in the Oligocene. Consistent with the first hypothesis, analyses of phylogenies supported increasing speciation rates and negligible extinction rates. In contrast, fossils showed that while speciation rates increased, speciation and extinction rates tended to be nearly equal, resulting in zero net diversification. Partially supporting the second hypothesis, the fossil data recorded a clear pattern of diversity decline in the Oligocene, although diversification rates were near zero. The phylogeny supported increased extinction ∼34 Ma, but also elevated extinction ∼10 Ma, coinciding with diversity declines in some fossil clades. The results demonstrated that estimates of speciation and extinction ignoring fossils are insufficient to infer diversification and information on extinct lineages should be incorporated into phylogenetic analyses. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

The early Eocene birds of the Messel fossil site: a 48 million-year-old bird community adds a temporal perspective to the evolution of tropical avifaunas.

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Mayr, Gerald

2017-05-01

Birds play an important role in studies addressing the diversity and species richness of tropical ecosystems, but because of the poor avian fossil record in all extant tropical regions, a temporal perspective is mainly provided by divergence dates derived from calibrated molecular analyses. Tropical ecosystems were, however, widespread in the Northern Hemisphere during the early Cenozoic, and the early Eocene German fossil site Messel in particular has yielded a rich avian fossil record. The Messel avifauna is characterized by a considerable number of flightless birds, as well as a high diversity of aerial insectivores and the absence of large arboreal birds. With about 70 currently known species in 42 named genus-level and at least 39 family-level taxa, it approaches extant tropical biotas in terms of species richness and taxonomic diversity. With regard to its taxonomic composition and presumed ecological characteristics, the Messel avifauna is more similar to the Neotropics, Madagascar, and New Guinea than to tropical forests in continental Africa and Asia. Because the former regions were geographically isolated during most of the Cenozoic, their characteristics may be due to the absence of biotic factors, especially those related to the diversification of placental mammals, which impacted tropical avifaunas in Africa and Asia. The crown groups of most avian taxa that already existed in early Eocene forests are species-poor. This does not support the hypothesis that the antiquity of tropical ecosystems is key to the diversity of tropical avifaunas, and suggests that high diversification rates may be of greater significance. © 2016 Cambridge Philosophical Society.

Organic preservation of fossil musculature with ultracellular detail.

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McNamara, Maria; Orr, Patrick J; Kearns, Stuart L; Alcalá, Luis; Anadón, Pere; Peñalver-Mollá, Enrique

2010-02-07

The very labile (decay-prone), non-biomineralized, tissues of organisms are rarely fossilized. Occurrences thereof are invaluable supplements to a body fossil record dominated by biomineralized tissues, which alone are extremely unrepresentative of diversity in modern and ancient ecosystems. Fossil examples of extremely labile tissues (e.g. muscle) that exhibit a high degree of morphological fidelity are almost invariably replicated by inorganic compounds such as calcium phosphate. There is no consensus as to whether such tissues can be preserved with similar morphological fidelity as organic remains, except when enclosed inside amber. Here, we report fossilized musculature from an approximately 18 Myr old salamander from lacustrine sediments of Ribesalbes, Spain. The muscle is preserved organically, in three dimensions, and with the highest fidelity of morphological preservation yet documented from the fossil record. Preserved ultrastructural details include myofilaments, endomysium, layering within the sarcolemma, and endomysial circulatory vessels infilled with blood. Slight differences between the fossil tissues and their counterparts in extant amphibians reflect limited degradation during fossilization. Our results provide unequivocal evidence that high-fidelity organic preservation of extremely labile tissues is not only feasible, but likely to be common. This is supported by the discovery of similarly preserved tissues in the Eocene Grube Messel biota.

Revisiting the origin and diversification of vascular plants through a comprehensive Bayesian analysis of the fossil record.

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Silvestro, Daniele; Cascales-Miñana, Borja; Bacon, Christine D; Antonelli, Alexandre

2015-07-01

Plants have a long evolutionary history, during which mass extinction events dramatically affected Earth's ecosystems and its biodiversity. The fossil record can shed light on the diversification dynamics of plant life and reveal how changes in the origination-extinction balance have contributed to shaping the current flora. We use a novel Bayesian approach to estimate origination and extinction rates in plants throughout their history. We focus on the effect of the 'Big Five' mass extinctions and on estimating the timing of origin of vascular plants, seed plants and angiosperms. Our analyses show that plant diversification is characterized by several shifts in origination and extinction rates, often matching the most important geological boundaries. The estimated origin of major plant clades predates the oldest macrofossils when considering the uncertainties associated with the fossil record and the preservation process. Our findings show that the commonly recognized mass extinctions have affected each plant group differently and that phases of high extinction often coincided with major floral turnovers. For instance, after the Cretaceous-Paleogene boundary we infer negligible shifts in diversification of nonflowering seed plants, but find significantly decreased extinction in spore-bearing plants and increased origination rates in angiosperms, contributing to their current ecological and evolutionary dominance. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Bayesian phylogenetic estimation of fossil ages.

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Drummond, Alexei J; Stadler, Tanja

2016-07-19

Recent advances have allowed for both morphological fossil evidence and molecular sequences to be integrated into a single combined inference of divergence dates under the rule of Bayesian probability. In particular, the fossilized birth-death tree prior and the Lewis-Mk model of discrete morphological evolution allow for the estimation of both divergence times and phylogenetic relationships between fossil and extant taxa. We exploit this statistical framework to investigate the internal consistency of these models by producing phylogenetic estimates of the age of each fossil in turn, within two rich and well-characterized datasets of fossil and extant species (penguins and canids). We find that the estimation accuracy of fossil ages is generally high with credible intervals seldom excluding the true age and median relative error in the two datasets of 5.7% and 13.2%, respectively. The median relative standard error (RSD) was 9.2% and 7.2%, respectively, suggesting good precision, although with some outliers. In fact, in the two datasets we analyse, the phylogenetic estimate of fossil age is on average less than 2 Myr from the mid-point age of the geological strata from which it was excavated. The high level of internal consistency found in our analyses suggests that the Bayesian statistical model employed is an adequate fit for both the geological and morphological data, and provides evidence from real data that the framework used can accurately model the evolution of discrete morphological traits coded from fossil and extant taxa. We anticipate that this approach will have diverse applications beyond divergence time dating, including dating fossils that are temporally unconstrained, testing of the 'morphological clock', and for uncovering potential model misspecification and/or data errors when controversial phylogenetic hypotheses are obtained based on combined divergence dating analyses.This article is part of the themed issue 'Dating species divergences using

Time-averaged molluscan death assemblages: Palimpsests of richness, snapshots of abundance

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Kidwell, Susan M.

2002-09-01

Field tests that compare living communities to associated dead remains are the primary means of estimating the reliability of biological information in the fossil record; such tests also provide insights into the dynamics of skeletal accumulation. Contrary to expectations, molluscan death assemblages capture a strong signal of living species' rank-order abundances. This finding, combined with independent evidence for exponential postmortem destruction of dead cohorts, argues that, although the species richness of a death assemblage may be a time-averaged palimpsest of the habitat (molluscan death assemblages contain, on average, ˜25% more species than any single census of the local live community, after sample-size standardization), species' relative-abundance data from the same assemblage probably constitute a much higher acuity record dominated by the most recent dead cohorts (e.g., from the past few hundred years or so, rather than the several thousand years recorded by the total assemblage and usually taken as the acuity of species-richness information). The pervasive excess species richness of molluscan death assemblages requires further analysis and modeling to discriminate among possible sources. However, time averaging alone cannot be responsible unless rare species (species with low rates of dead-shell production) are collectively more durable (have longer taphonomic half-lives) than abundant species. Species richness and abundance data thus appear to present fundamentally different taphonomic qualities for paleobiological analysis. Relative- abundance information is more snapshot-like and thus taphonomically more straightforward than expected, especially compared to the complex origins of dead-species richness.

Fossil record of stem groups employed in evaluating the chronogram of insects (Arthropoda: Hexapoda)

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Wang, Yan-hui; Engel, Michael S.; Rafael, José A.; Wu, Hao-yang; Rédei, Dávid; Xie, Qiang; Wang, Gang; Liu, Xiao-guang; Bu, Wen-jun

2016-01-01

Insecta s. str. (=Ectognatha), comprise the largest and most diversified group of living organisms, accounting for roughly half of the biodiversity on Earth. Understanding insect relationships and the specific time intervals for their episodes of radiation and extinction are critical to any comprehensive perspective on evolutionary events. Although some deeper nodes have been resolved congruently, the complete evolution of insects has remained obscure due to the lack of direct fossil evidence. Besides, various evolutionary phases of insects and the corresponding driving forces of diversification remain to be recognized. In this study, a comprehensive sample of all insect orders was used to reconstruct their phylogenetic relationships and estimate deep divergences. The phylogenetic relationships of insect orders were congruently recovered by Bayesian inference and maximum likelihood analyses. A complete timescale of divergences based on an uncorrelated log-normal relaxed clock model was established among all lineages of winged insects. The inferred timescale for various nodes are congruent with major historical events including the increase of atmospheric oxygen in the Late Silurian and earliest Devonian, the radiation of vascular plants in the Devonian, and with the available fossil record of the stem groups to various insect lineages in the Devonian and Carboniferous. PMID:27958352

New Biogeographic insight into Bauhinia s.l. (Leguminosae): integration from fossil records and molecular analyses.

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Meng, Hong-Hu; Jacques, Frédéric Mb; Su, Tao; Huang, Yong-Jiang; Zhang, Shi-Tao; Ma, Hong-Jie; Zhou, Zhe-Kun

2014-08-10

Given that most species that have ever existed on earth are extinct, it stands to reason that the evolutionary history can be better understood with fossil taxa. Bauhinia is a typical genus of pantropical intercontinental disjunction among the Asian, African, and American continents. Geographic distribution patterns are better recognized when fossil records and molecular sequences are combined in the analyses. Here, we describe a new macrofossil species of Bauhinia from the Upper Miocene Xiaolongtan Formation in Wenshan County, Southeast Yunnan, China, and elucidate the biogeographic significance through the analyses of molecules and fossils. Morphometric analysis demonstrates that the leaf shapes of B. acuminata, B. championii, B. chalcophylla, B. purpurea, and B. podopetala closely resemble the leaf shapes of the new finding fossil. Phylogenetic relationships among the Bauhinia species were reconstructed using maximum parsimony and Bayesian inference, which inferred that species in Bauhinia species are well-resolved into three main groups. Divergence times were estimated by the Bayesian Markov chain Monte Carlo (MCMC) method under a relaxed clock, and inferred that the stem diversification time of Bauhinia was ca. 62.7 Ma. The Asian lineage first diverged at ca. 59.8 Ma, followed by divergence of the Africa lineage starting during the late Eocene, whereas that of the neotropical lineage starting during the middle Miocene. Hypotheses relying on vicariance or continental history to explain pantropical disjunct distributions are dismissed because they require mostly Palaeogene and older tectonic events. We suggest that Bauhinia originated in the middle Paleocene in Laurasia, probably in Asia, implying a possible Tethys Seaway origin or an "Out of Tropical Asia", and dispersal of legumes. Its present pantropical disjunction resulted from disruption of the boreotropical flora by climatic cooling after the Paleocene-Eocene Thermal Maximum (PETM). North Atlantic land

Evaluation of the fossil fish-specific diversity in a chadian continental assemblage: Exploration of morphological continuous variation in Synodontis (Ostariophysi, Siluriformes).

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Pinton, Aurélie; Le Fur, Soizic; Otero, Olga

2016-11-01

In the fossil record, the quantification of continuous morphological variation has become a central issue when dealing with species identification and speciation. In this context, fossil taxa with living representatives hold great promise, because of the potential to characterise patterns of intraspecific morphological variation in extant species prior to any interpretation in the fossil record. The vast majority of catfish families fulfil this prerequisite, as most of them are represented by extant genera. However, although they constitute a major fish group in terms of distribution, and ecological and taxonomic diversity, the quantitative study of their past morphological variation has been neglected, as fossil specimens are generally identified based on the scarcest remains, that is, complete neurocrania that bear discrete characters. Consequently, a part of freshwater catfish history is unprospected and unknown. In this study, we explored the morphological continuous variation of the humeral plate shape in Synodontis catfishes using Elliptic Fourier Analysis (EFA), and compared extant members and fossil counterparts. We analysed 153 extant specimens of 11 Synodontis species present in the Chad basin, in addition to 23 fossil specimens from the Chadian fossiliferous area of Toros Menalla which is dated around 7 Ma. This highly speciose genus, which is one of the most diversified in Africa, exhibits a rich fossil record with several hundred remains mostly identified as Synodontis sp. The analysis of the outline of the humeral plate reveals that some living morphological types were already represented in the Chad Basin 7 My ago, and allows for the discovery of extinct species. Beside illuminating the complex Neogene evolutionary history of Synodontis, these results underline the interest in the ability of isolated remains to reconstruct a past dynamic history and to validate the relevance of EFA as a tool to explore specific diversity through time. J. Morphol. 277

Individual to Community-Level Faunal Responses to Environmental Change from a Marine Fossil Record of Early Miocene Global Warming

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Belanger, Christina L.

2012-01-01

Modern climate change has a strong potential to shift earth systems and biological communities into novel states that have no present-day analog, leaving ecologists with no observational basis to predict the likely biotic effects. Fossil records contain long time-series of past environmental changes outside the range of modern observation, which are vital for predicting future ecological responses, and are capable of (a) providing detailed information on rates of ecological change, (b) illuminating the environmental drivers of those changes, and (c) recording the effects of environmental change on individual physiological rates. Outcrops of Early Miocene Newport Member of the Astoria Formation (Oregon) provide one such time series. This record of benthic foraminiferal and molluscan community change from continental shelf depths spans a past interval environmental change (∼20.3-16.7 mya) during which the region warmed 2.1–4.5°C, surface productivity and benthic organic carbon flux increased, and benthic oxygenation decreased, perhaps driven by intensified upwelling as on the modern Oregon coast. The Newport Member record shows that (a) ecological responses to natural environmental change can be abrupt, (b) productivity can be the primary driver of faunal change during global warming, (c) molluscs had a threshold response to productivity change while foraminifera changed gradually, and (d) changes in bivalve body size and growth rates parallel changes in taxonomic composition at the community level, indicating that, either directly or indirectly through some other biological parameter, the physiological tolerances of species do influence community change. Ecological studies in modern and fossil records that consider multiple ecological levels, environmental parameters, and taxonomic groups can provide critical information for predicting future ecological change and evaluating species vulnerability. PMID:22558424

Mesozoic Coleopteran Faunas from Argentina: Geological Context, Diversity, Taphonomic Observations, and Comparison with Other Fossil Insect Records

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María Belén Lara

2012-01-01

Full Text Available The order Coleoptera is the most diversified group of the Class Insecta and is the largest group of the Animal Kingdom. This contribution reviews the Mesozoic insects and especially the coleopteran records from Argentina, based on bibliographical and unpublished materials (86 described species, 526 collected specimens. The material came from different geological units from the late Middle Triassic to the Late Triassic (Bermejo, Cuyo, and Malargüe basins to the Middle-Late Jurassic and Early Cretaceous (Deseado Massif, Cañadón Asfalto, and San Luís Basin. The coleopteran record is composed of 29 described species with 262 collected specimens (isolated elytra mainly represented by Triassic species and only four specimens recorded in Jurassic units, all of them currently unpublished. These fossil coleopterans provide fundamental information about the evolution of insects in the Southern Hemisphere and confirm the Triassic Argentinean insect deposits to be among the most important in the world.

Preservation of three-dimensional anatomy in phosphatized fossil arthropods enriches evolutionary inference.

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Schwermann, Achim H; Dos Santos Rolo, Tomy; Caterino, Michael S; Bechly, Günter; Schmied, Heiko; Baumbach, Tilo; van de Kamp, Thomas

2016-02-05

External and internal morphological characters of extant and fossil organisms are crucial to establishing their systematic position, ecological role and evolutionary trends. The lack of internal characters and soft-tissue preservation in many arthropod fossils, however, impedes comprehensive phylogenetic analyses and species descriptions according to taxonomic standards for Recent organisms. We found well-preserved three-dimensional anatomy in mineralized arthropods from Paleogene fissure fillings and demonstrate the value of these fossils by utilizing digitally reconstructed anatomical structure of a hister beetle. The new anatomical data facilitate a refinement of the species diagnosis and allowed us to reject a previous hypothesis of close phylogenetic relationship to an extant congeneric species. Our findings suggest that mineralized fossils, even those of macroscopically poor preservation, constitute a rich but yet largely unexploited source of anatomical data for fossil arthropods.

A new fossil cichlid from the Middle Miocene in the East African Rift Valley (Tugen Hills, Central Kenya: First record of a putative Ectodini

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Melanie Altner

2015-11-01

Full Text Available Identification of fossil cichlids is difficult, because the currently used diagnostic morphological characters for living cichlids are mostly soft tissue based and such characters are hardly preserved in fossils. During our recent fieldwork in the Central Kenya Rift (E-Africa, we discovered several exceptionally well-preserved fossil cichlids, which can be assigned to different lineages among the African Pseudocrenilabrinae. Here we present one of those new specimens. Its most conspicuous character is a lateral line divided into three segments. This specimen was found in the lacustrine sediments of the Middle Miocene site Waril, Tugen Hills, Kenya. The site represents the deposits of an ancient freshwater lake ca. 9-10 million years ago. Previous work on fossil leaves from the same site allow for the reconstruction of open vegetation surrounding the lake and pronounced dry seasons. Among the main further characteristics of the new fossil cichlid is a lachrimal with six lateral line canals, big cycloid scales and a low number of dorsal fin spines (XIII. The latter two characters are traceable in several members of tribes within the Pseudocrenilabrinae. However, a lachrimal with six lateral line canals is exclusively found in certain tribes of the EAR (East African Radiation within the Pseudocrenilabrinae. Moreover, the unique lateral line pattern is solely present in two genera of the EAR tribe Ectodini. However, the fossil shows cycloid scales, while modern Ectodini have ctenoid scales. Taken all evidence together, this fossil may perhaps represent an ancient lineage related to the Ectodini. Up to date, there is no definite fossil record of the members of the EAR. Our fossil may represent the first reliable calibration point for this group, which would be consistent with the previously reconstructed diversification time of the H-lineage (EAR tribes, except Boulengerochromini, Bathybatini, Trematocarini and Lamprologini and the Lamprologini ca

Radiocarbon Records of Fossil Fuel Emissions From Urban Trees in the Greater Salt Lake Valley From Mid-Century to Present.

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Chritz, K.; Buchert, M.; Walker, J. C.; Mendoza, D.; Pataki, D. E.; Xu, X.; Lin, J. C.

2017-12-01

Generating long term records of fossil fuel emissions of urban environments is complicated by the fact that direct observations of emissions and urban atmospheric CO2 concentrations were only collected in the recent past. Radiocarbon (14C) in tree rings from urban trees can provide archives of fossil fuel emissions that may track population growth over time, as higher population density is typically correlated with increased vehicular traffic and associated CO2 emissions, which are radiocarbon dead. We present radiocarbon measurements (n=125) from five roadside green ash trees (Fraxinus pennsylvanica) located in three cities of northern Utah - Salt Lake City (urban, 2016 population: 193,744), Logan City (agricultural, 2016 population: 49,110) and Heber (rural, 2016 population: 14,969). Urban trees were cored in four cardinal directions and ring widths were measured and counted to establish a chronology. One ring from every third year in a single core from each tree was removed and holocellulose was extracted from bulk wood of individual rings for 14C analysis. Fraction CO2 from fossil fuel burning (CO2-ff) was calculated using a simple mass-balance calculation from measured 14C values and remote background atmospheric 14CO2 values for NH Zone 2. The data from all three cities indicate a general trend of increasing CO2-ff uptake by the trees from 1980s to present, as expected with increased population growth and vehicular traffic. However, records in all three cities show unique elevated CO2-ff prior to the 1980s, assuming similar climate patterns through time, diverging from historic population size. We employed atmospheric simulations from the STILT (Stochastic Time-Inverted Lagrangian Transport) models for each of these trees to create footprints to determine source areas for CO2. These footprints reveal that atmospheric sampling areas can be large for certain trees, and other sources of 14C dead carbon, such as coal and natural gas from industrial emissions

Microbe-like inclusions in tree resins and implications for the fossil record of protists in amber.

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Thiel, V; Lausmaa, J; Sjövall, P; Ragazzi, E; Seyfullah, L J; Schmidt, A R

2016-07-01

During the past two decades, a plethora of fossil micro-organisms have been described from various Triassic to Miocene ambers. However, in addition to entrapped microbes, ambers commonly contain microscopic inclusions that sometimes resemble amoebae, ciliates, microfungi, and unicellular algae in size and shape, but do not provide further diagnostic features thereof. For a better assessment of the actual fossil record of unicellular eukaryotes in amber, we studied equivalent inclusions in modern resin of the Araucariaceae; this conifer family comprises important amber-producers in Earth history. Using time-of-flight secondary ion mass spectrometry (ToF-SIMS), we investigated the chemical nature of the inclusion matter and the resin matrix. Whereas the matrix, as expected, showed a more hydrocarbon/aromatic-dominated composition, the inclusions contain abundant salt ions and polar organics. However, the absence of signals characteristic for cellular biomass, namely distinctive proteinaceous amino acids and lipid moieties, indicates that the inclusions do not contain microbial cellular matter but salts and hydrophilic organic substances that probably derived from the plant itself. Rather than representing protists or their remains, these microbe-like inclusions, for which we propose the term 'pseudoinclusions', consist of compounds that are immiscible with the terpenoid resin matrix and were probably secreted in small amounts together with the actual resin by the plant tissue. Consequently, reports of protists from amber that are only based on the similarity of the overall shape and size to extant taxa, but do not provide relevant features at light-microscopical and ultrastructural level, cannot be accepted as unambiguous fossil evidence for these particular groups. © 2016 John Wiley & Sons Ltd.

Paleovegetation changes recorded by n-alkyl lipids bound in macromolecules of plant fossils and kerogens from the Cretaceous sediments in Japan

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Miyata, Y.; Sawada, K.; Nakamura, H.; Takashima, R.; Takahashi, M.

2014-12-01

Resistant macromolecules composing living plant tissues tend to be preserved through degradation and diagenesis, hence constituate major parts of sedimentary plant-derived organic matter (kerogen), and their monomer compositions vary widely among different plant taxa, organs and growth stages. Thus, analysis of such macromolecule may serve as new technique for paleobotanical evaluation distinctive from classical paleobotnical studies depends on morphological preservation of fossils. In the present study, we analyzed plant fossils and kerogens in sediments from the Cretaceous strata in Japan to examine chemotaxonomic characteristics of fossil macromolecules and to reconstruct paleovegetation change by kerogen analysis. The kerogens were separated from the powdered sediments of Cretaceous Yezo Group, Hokkaido, Japan. All kerogens have been confirmed to be mostly originated from land plant tissues by microscopic observation. Mummified angiosperm and gymnosperm fossil leaves were separated from carbonaceous sandstone of the Cretaceous Ashizawa Formation, Futaba Group. The kerogens and plant fossils were extracted with methanol and dichloromethane, and were subsequently refluxed under 110°C to remove free compounds completely. The residues are hydrolyzed by KOH/methanol under 110°C. These released compounds are analyzed by GC-MS. As main hydrolyzed products (ester-bound molecular units) from all kerogens, C10-C28 n-alkanoic acids and C10-C30 n-alkanols were detected. Recent studies on the hydrolysis products of plant tissues suggested the long chain (>C20) n-alkanols were predominantly abundant in deciduous broadleaved angiosperms. Correspondingly, the stratigraphic variation of the ratios of long chain (>C20) n-alkanols to fatty acids was concordant with the variation of angiosperm/gymnosperm ratios recorded by land plant-derived terpenoid biomarkers. In addition, we found that the long chain n-alkanols/fatty acids ratio in the angiosperm fossil leaf was

The oldest Mahonia (Berberidaceae) fossil from East Asia and its biogeographic implications.

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Huang, Jian; Su, Tao; Lebereton-Anberrée, Julie; Zhang, Shi-Tao; Zhou, Zhe-Kun

2016-03-01

Interpretation of the biogeography of the genus Mahonia (Berberidaceae) is limited by the lack of fossil records in East Asia. Compressed fossil foliage, described here as Mahonia mioasiatica sp. nov., were collected from the Upper Miocene Xiaolongtan Formation in Wenshan, Yunnan, southwest China. These specimens represent the oldest reliable fossil record of Mahonia in East Asia. This new fossil species shows a general similarity to Group Orientales and is most similar to the extant eastern Asian Mahonia conferta. Considering other fossil evidence of Mahonia, we propose a migration route of this genus to Asia over the North Atlantic Land Bridge rather than the Bering Land Bridge. Our results also suggest that North America, Europe and East Asia have been successive centers of diversity for the genus, as a consequence of diversification in Group Orientales potentially related to historical climate change.

New fossil seeds of Eurya (Theaceae from East Asia and their paleobiogeographic implications

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Hai Zhu

2016-06-01

Full Text Available Eurya has an excellent fossil record in Europe, but it has only a few fossil occurrences in East Asia though this vast area houses the highest modern diversity of the genus. In this study, three-dimensionally preserved fossil seeds of Eurya stigmosa (Ludwig Mai from the late Pliocene of northwestern Yunnan, southwestern China are described. The seeds are compressed and flattened, slightly campylotropous, and nearly circular to slightly angular in shape. The surface of the seeds is sculptured by a distinctive foveolate pattern, consisting of funnel-shaped and finely pitted cells. Each seed valve contains a reniform or horseshoe-shaped embryo cavity, a characteristic condyle structure and an internal raphe. These fossil seeds represent one of the few fossil records of Eurya in East Asia. This new finding therefore largely extends the distributional ranges of Eurya during Neogene. Fossil records summarized here show that Eurya persisted in Europe until the early Pleistocene, but disappeared thereafter. The genus might have first appeared in East Asia no later than the late Oligocene, and dispersed widely in regions such as Japan, Nepal, and southwestern China.

The fossil record of phenotypic integration and modularity: A deep-time perspective on developmental and evolutionary dynamics.

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Goswami, Anjali; Binder, Wendy J; Meachen, Julie; O'Keefe, F Robin

2015-04-21

Variation is the raw material for natural selection, but the factors shaping variation are still poorly understood. Genetic and developmental interactions can direct variation, but there has been little synthesis of these effects with the extrinsic factors that can shape biodiversity over large scales. The study of phenotypic integration and modularity has the capacity to unify these aspects of evolutionary study by estimating genetic and developmental interactions through the quantitative analysis of morphology, allowing for combined assessment of intrinsic and extrinsic effects. Data from the fossil record in particular are central to our understanding of phenotypic integration and modularity because they provide the only information on deep-time developmental and evolutionary dynamics, including trends in trait relationships and their role in shaping organismal diversity. Here, we demonstrate the important perspective on phenotypic integration provided by the fossil record with a study of Smilodon fatalis (saber-toothed cats) and Canis dirus (dire wolves). We quantified temporal trends in size, variance, phenotypic integration, and direct developmental integration (fluctuating asymmetry) through 27,000 y of Late Pleistocene climate change. Both S. fatalis and C. dirus showed a gradual decrease in magnitude of phenotypic integration and an increase in variance and the correlation between fluctuating asymmetry and overall integration through time, suggesting that developmental integration mediated morphological response to environmental change in the later populations of these species. These results are consistent with experimental studies and represent, to our knowledge, the first deep-time validation of the importance of developmental integration in stabilizing morphological evolution through periods of environmental change.

Corrected placement of Mus-Rattus fossil calibration forces precision in the molecular tree of rodents.

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Kimura, Yuri; Hawkins, Melissa T R; McDonough, Molly M; Jacobs, Louis L; Flynn, Lawrence J

2015-09-28

Time calibration derived from the fossil record is essential for molecular phylogenetic and evolutionary studies. Fossil mice and rats, discovered in the Siwalik Group of Pakistan, have served as one of the best-known fossil calibration points in molecular phylogenic studies. Although these fossils have been widely used as the 12 Ma date for the Mus/Rattus split or a more basal split, conclusive paleontological evidence for the nodal assignments has been absent. This study analyzes newly recognized characters that demonstrate lineage separation in the fossil record of Siwalik murines and examines the most reasonable nodal placement of the diverging lineages in a molecular phylogenetic tree by ancestral state reconstruction. Our specimen-based approach strongly indicates that Siwalik murines of the Karnimata clade are fossil members of the Arvicanthini-Otomyini-Millardini clade, which excludes Rattus and its relatives. Combining the new interpretation with the widely accepted hypothesis that the Progonomys clade includes Mus, the lineage separation event in the Siwalik fossil record represents the Mus/Arvicanthis split. Our test analysis on Bayesian age estimates shows that this new calibration point provides more accurate estimates of murine divergence than previous applications. Thus, we define this fossil calibration point and refine two other fossil-based points for molecular dating.

From Fossil Parasitoids to Vectors: Insects as Parasites and Hosts.

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Nagler, Christina; Haug, Joachim T

2015-01-01

Within Metazoa, it has been proposed that as many as two-thirds of all species are parasitic. This propensity towards parasitism is also reflected within insects, where several lineages independently evolved a parasitic lifestyle. Parasitic behaviour ranges from parasitic habits in the strict sense, but also includes parasitoid, phoretic or kleptoparasitic behaviour. Numerous insects are also the host for other parasitic insects or metazoans. Insects can also serve as vectors for numerous metazoan, protistan, bacterial and viral diseases. The fossil record can report this behaviour with direct (parasite associated with its host) or indirect evidence (insect with parasitic larva, isolated parasitic insect, pathological changes of host). The high abundance of parasitism in the fossil record of insects can reveal important aspects of parasitic lifestyles in various evolutionary lineages. For a comprehensive view on fossil parasitic insects, we discuss here different aspects, including phylogenetic systematics, functional morphology and a direct comparison of fossil and extant species. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fossilized Mammalian Erythrocytes Associated With a Tick Reveal Ancient Piroplasms.

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Poinar, George

2017-07-01

Ticks transmit a variety of pathogenic organisms to vertebrates, especially mammals. The fossil record of such associations is extremely rare. An engorged nymphal tick of the genus Ambylomma in Dominican amber was surrounded by erythrocytes from its mammalian host. Some of the exposed erythrocytes contained developmental stages of a hemoprotozoan resembling members of the Order Piroplasmida. The fossil piroplasm is described, its stages compared with those of extant piroplasms, and reasons provided why the mammalian host could have been a primate. The parasites were also found in the gut epithelial cells and body cavity of the fossil tick. Aside from providing the first fossil mammalian red blood cells and the first fossil intraerythrocytic hemoparasites, the present discovery shows that tick-piroplasm associations were already well established in the Tertiary. This discovery provides a timescale that can be used in future studies on the evolution of the Piroplasmida. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com Version of Record, first published online March 20, 2017 with fixed content and layout in compliance with Art. 8.1.3.2 ICZN.

Borneo: a quantitative analysis of botanical richness, endemicity and floristic regions based on herbarium records

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Raes, Niels

2009-01-01

Based on the digitized herbarium records housed at the National Herbarium of the Netherlands I developed high spatial resolution patterns of Borneo's botanical richness, endemicity, and the floristic regions. The patterns are derived from species distribution models which predict a species occurrence based on the identified relationships between species recorded presences and the ecological circumstances at those localities. A new statistical method was developed to test the species distribut...

From Fossils to Astrobiology Records of Life on Earth and Search for Extraterrestrial Biosignatures

CERN Document Server

Seckbach, Joseph

2008-01-01

From Fossils to Astrobiology reviews developments in paleontology and geobiology that relate to the rapidly-developing field of Astrobiology, the study of life in the Universe. Many traditional areas of scientific study, including astronomy, chemistry and planetary science, contribute to Astrobiology, but the study of the record of life on planet Earth is critical in guiding investigations in the rest of the cosmos. In this varied book, expert scientists from 15 countries present peer-reviewed, stimulating reviews of paleontological and astrobiological studies. The overviews of established and emerging techniques for studying modern and ancient microorganisms on Earth and beyond, will be valuable guides to evaluating biosignatures which could be found in the extraterrestrial surface or subsurface within the Solar System and beyond. This volume also provides discussion on the controversial reports of "nanobacteria" in the Martian meteorite ALH84001. It is a unique volume among Astrobiology monographs in focusi...

Borneo : a quantitative analysis of botanical richness, endemicity and floristic regions based on herbarium records

NARCIS (Netherlands)

Raes, Niels

2009-01-01

Based on the digitized herbarium records housed at the National Herbarium of the Netherlands I developed high spatial resolution patterns of Borneo's botanical richness, endemicity, and the floristic regions. The patterns are derived from species distribution models which predict a species

First forensic records of termite activity on non-fossilized human bones in Brazil

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R. A. Queiroz

Full Text Available Abstract The aim of this study was to describe the first records of termite activity on non-fossilized human bones in Brazil. The cases reported in this study resulted from forensic analysis of six human skeletons found in northeastern Brazil between 2012 and 2014. Traces of tunnels and nests commonly produced by termites were found on several human bone surfaces as well as the specimens and characteristic signs of osteophagic activity. In four cases, the species were identified: Amitermes amifer Silvestri, 1901, Nasutitermes corniger (Motschulsky, 1855 (on two skeletons, and Microcerotermes indistinctus Mathews, 1977. In two other cases, the activity of termites on bone surfaces was evidenced by remains of nests and tunnels produced by these insects. At least in the samples of human remains available for this report, the number of termites collected was greater on bones found during autumn, the rainy season in the Northeast of Brazil. The human bones examined showed termites like insects with lots of strength at bone degradation, capable of continuing the process of decomposition of human remains even in completely skeletonized bodies.

First fossil record of Alphonsea Hk. f. & T. (Annonaceae from the Late Oligocene sediments of Assam, India and comments on its phytogeography.

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Gaurav Srivastava

Full Text Available A new fossil leaf impression of Alphonsea Hk. f. & T. of the family Annonaceae is described from the Late Oligocene sediments of Makum Coalfield, Assam, India. This is the first authentic record of the fossil of Alphonsea from the Tertiary rocks of South Asia. The Late Oligocene was the time of the last significant globally warm climate and the fossil locality was at 10°-15°N palaeolatitude. The known palaeoflora and sedimentological studies indicate a fluvio-marine deltaic environment with a mosaic of mangrove, fluvial, mire and lacustrine depositional environments. During the depositional period the suturing between the Indian and Eurasian plates was not complete to facilitate the plant migration. The suturing was over by the end of the Late Oligocene/beginning of Early Miocene resulting in the migration of the genus to Southeast Asia where it is growing profusely at present. The present study is in congruence with the earlier published palaeofloral and molecular phylogenetic data. The study also suggests that the Indian plate was not only a biotic ferry during its northward voyage from Gondwana to Asia but also a place for the origin of several plant taxa.

Fossil Hunting: Intracluster Stars in Virgo

NARCIS (Netherlands)

Murphy, Eric; Bridge, Carrie; Desai, Vandana; Kenney, Jeffrey; Krick, Jessica; Surace, Jason; van Gorkom, Jacqueline

2009-01-01

In dense clusters, galaxy interactions and mergers play a significant role in galaxy evolution. During these interactions, tidal forces can lead to the ejection of stars from their parent galaxies; these stars are a fossil record of environmentally-driven galaxy evolution. We propose to map the

Fossil isotope records of seasonal climate and ecology: Straight from the horse's mouth

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Sharp, Z. D.; Cerling, T. E.

1998-03-01

Isotope analysis of a bulk fossil tooth gives a “snapshot” impression of paleoclimatic conditions—a single point in time. However, hypsodont teeth grow over a period of a year or more, so that stable carbon and oxygen isotope variations along their length are a “tape recorder” of short-term seasonal variations from the distant past. We have used a new in situ micro-laser sampling method to determine submillimeter carbon and oxygen isotope variations in the enamel of individual fossil horse teeth to assess ancient annual meteoric water variations and feeding patterns. The δ18O values from a 6.8 Ma fossil horse tooth (Astrohippus ansae) from Texas vary cyclically along the 6 cm length of the tooth with a smoothed amplitude of >4‰, similar to the monthly averaged amplitude measured in modern meteoric waters from the region. The seasonal δ18O values are ˜3‰ to 4‰ higher than those calculated from modern meteoric water data, suggesting either a higher local meteoric water value in the Miocene of Texas, or that the animal received a high proportion of its dietary water from plants or highly evaporated water. A Holocene horse tooth from the shores of Glacial Lake Agassiz, North Dakota (Equus sp.), also has isotopic variations with the same 35 mm periodicity, but a smoothed amplitude of only 2‰. This horse most likely had a buffered drinking supply. The calculated δ18O of the water in equilibrium with this tooth is the same as the modern measured annual average. The variations within a single tooth can be as large as those generally observed in entire stratigraphic sections of fossil teeth analyzed by bulk methods. The new method provides an important technique for evaluating fossil diagenesis; conventional bulk analyses of teeth fragments may not be representative of the whole tooth, thus explaining analytical scatter that has been previously attributed to diagenesis.

Evaluation of sustainability by a population living near fossil fuel resources in Northwestern Greece.

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Vatalis, Konstantinos I

2010-12-01

The emergence of sustainability as a goal in the management of fossil fuel resources is a result of the growing global environmental concern, and highlights some of the issues expected to be significant in coming years. In order to secure social acceptance, the mining industry has to face these challenges by engaging its many different stakeholders and examining their sustainability concerns. For this reason a questionnaire was conducted involving a simple random sampling of inhabitants near an area rich in fossil fuel resources, in order to gather respondents' views on social, economic and environmental benefits. The study discusses new subnational findings on public attitudes to regional sustainability, based on a quantitative research design. The site of the study was the energy-rich Greek region of Kozani, Western Macedonia, one of the country's energy hubs. The paper examines the future perspectives of the area. The conclusions can form a useful framework for energy policy in the wider Balkan area, which contains important fossil fuel resources. Copyright © 2010 Elsevier Ltd. All rights reserved.

Reconstructing Carotenoid-Based and Structural Coloration in Fossil Skin.

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McNamara, Maria E; Orr, Patrick J; Kearns, Stuart L; Alcalá, Luis; Anadón, Pere; Peñalver, Enrique

2016-04-25

Evidence of original coloration in fossils provides insights into the visual communication strategies used by ancient animals and the functional evolution of coloration over time [1-7]. Hitherto, all reconstructions of the colors of reptile integument and the plumage of fossil birds and feathered dinosaurs have been of melanin-based coloration [1-6]. Extant animals also use other mechanisms for producing color [8], but these have not been identified in fossils. Here we report the first examples of carotenoid-based coloration in the fossil record, and of structural coloration in fossil integument. The fossil skin, from a 10 million-year-old colubrid snake from the Late Miocene Libros Lagerstätte (Teruel, Spain) [9, 10], preserves dermal pigment cells (chromatophores)-xanthophores, iridophores, and melanophores-in calcium phosphate. Comparison with chromatophore abundance and position in extant reptiles [11-15] indicates that the fossil snake was pale-colored in ventral regions; dorsal and lateral regions were green with brown-black and yellow-green transverse blotches. Such coloration most likely functioned in substrate matching and intraspecific signaling. Skin replicated in authigenic minerals is not uncommon in exceptionally preserved fossils [16, 17], and dermal pigment cells generate coloration in numerous reptile, amphibian, and fish taxa today [18]. Our discovery thus represents a new means by which to reconstruct the original coloration of exceptionally preserved fossil vertebrates. Copyright © 2016 Elsevier Ltd. All rights reserved.

New methods reveal oldest known fossil epiphyllous moss: Bryiidites utahensis gen. et sp. nov. (Bryidae).

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Barclay, Richard S; McElwain, Jennifer C; Duckett, Jeffrey G; van Es, Maarten H; Mostaert, Anika S; Pressel, Silvia; Sageman, Bradley B

2013-12-01

Epiphyllous bryophytes are a highly characteristic feature of many humid tropical forest ecosystems. In contrast to the extensive fossil record for the leaves of their host plants, the record is virtually nonexistent for the epiphylls themselves, despite a fossil record for mosses that begins in the Middle Carboniferous Period, 330 million years ago. Epifluorescence optical microscopy, scanning electron microscopy, and atomic force microscopy were employed to investigate an intimate association between a newly discovered epiphyllous moss and a Lauraceae plant host from the middle Cretaceous. We describe the oldest fossil specimen of an epiphyllous moss, Bryiidites utahensis gen. et sp. nov., identified from an individual specimen only 450 µm long, situated on an approximately one millimeter square fossil leaf fragment. The moss epiphyll is exquisitely preserved as germinating spores and short-celled protonemata with transverse and oblique cross-walls closely matching those of extant epiphyllous mosses on the surface of the plant-leaf hosts. The extension of the epiphyll record back to the middle Cretaceous provides fossil evidence for the appearance of epiphyllous mosses during the diversification of flowering plants, at least 95 million years ago. It also provides substantive evidence for a tropical maritime climate in central North America during the middle Cretaceous.

Implications of a fossil stickleback assemblage for Darwinian gradualism.

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Bell, M A

2009-11-01

Darwin postulated that a complete fossil record would contain numerous gradual transitions between ancestral and descendant species, but 150 years after publication of The Origin of Species, few such transitions have materialized. The fossil stickleback Gasterosteus doryssus and the deposit in which it occurs provide excellent conditions to detect such transitions. Abundant, well-preserved fossils occur in a stratigraphic setting with fine temporal resolution. The paleoecology of G. doryssus resembles the ecology of modern lakes that harbour the phenotypically similar three-spined stickleback Gasterosteus aculeatus. Gasterosteus aculeatus are primitively highly armoured, but G. doryssus comprised two contemporaneous biological species with relatively weak armour, including a near-shore, benthic feeder (benthic) and an offshore planktivore (limnetic). The benthic species expanded its range into the limnetic zone of the lake, where it apparently switched to planktivory and evolved reduced armour within c. 5000 years in response to directional selection. Although gradual evolution of mean phenotypes occurred, a single major gene caused much of evolutionary change of the pelvic skeleton. Thus, Darwin's expectation that transitions between species in the fossil record would be gradual was met at a fine time scale, but for pelvic structure, a well-studied trait, his expectation that gradual change would depend entirely on numerous, small, heritable differences among individuals was incorrect.

Fossil birds in the National Museum of Natural History, Sofia: composition, development and scientific value

NARCIS (Netherlands)

Boev, Z.N.

2005-01-01

A review of the fossil and subfossil avian record kept in Bulgaria is presented. The only collection of fossil birds in Bulgaria was established in the 1980s. 99.6% originates from 98 localities throughout Bulgaria. Foreign fossils originate from Azerbaijan, Greece, Hungary, Namibia and New Zealand.

Testing the effect of the rock record on diversity: a multidisciplinary approach to elucidating the generic richness of sauropodomorph dinosaurs through time.

Science.gov (United States)

Mannion, Philip D; Upchurch, Paul; Carrano, Matthew T; Barrett, Paul M

2011-02-01

The accurate reconstruction of palaeobiodiversity patterns is central to a detailed understanding of the macroevolutionary history of a group of organisms. However, there is increasing evidence that diversity patterns observed directly from the fossil record are strongly influenced by fluctuations in the quality of our sampling of the rock record; thus, any patterns we see may reflect sampling biases, rather than genuine biological signals. Previous dinosaur diversity studies have suggested that fluctuations in sauropodomorph palaeobiodiversity reflect genuine biological signals, in comparison to theropods and ornithischians whose diversity seems to be largely controlled by the rock record. Most previous diversity analyses that have attempted to take into account the effects of sampling biases have used only a single method or proxy: here we use a number of techniques in order to elucidate diversity. A global database of all known sauropodomorph body fossil occurrences (2024) was constructed. A taxic diversity curve for all valid sauropodomorph genera was extracted from this database and compared statistically with several sampling proxies (rock outcrop area and dinosaur-bearing formations and collections), each of which captures a different aspect of fossil record sampling. Phylogenetic diversity estimates, residuals and sample-based rarefaction (including the first attempt to capture 'cryptic' diversity in dinosaurs) were implemented to investigate further the effects of sampling. After 'removal' of biases, sauropodomorph diversity appears to be genuinely high in the Norian, Pliensbachian-Toarcian, Bathonian-Callovian and Kimmeridgian-Tithonian (with a small peak in the Aptian), whereas low diversity levels are recorded for the Oxfordian and Berriasian-Barremian, with the Jurassic/Cretaceous boundary seemingly representing a real diversity trough. Observed diversity in the remaining Triassic-Jurassic stages appears to be largely driven by sampling effort. Late

Estimating Age-Dependent Extinction: Contrasting Evidence from Fossils and Phylogenies.

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Hagen, Oskar; Andermann, Tobias; Quental, Tiago B; Antonelli, Alexandre; Silvestro, Daniele

2018-05-01

The estimation of diversification rates is one of the most vividly debated topics in modern systematics, with considerable controversy surrounding the power of phylogenetic and fossil-based approaches in estimating extinction. Van Valen's seminal work from 1973 proposed the "Law of constant extinction," which states that the probability of extinction of taxa is not dependent on their age. This assumption of age-independent extinction has prevailed for decades with its assessment based on survivorship curves, which, however, do not directly account for the incompleteness of the fossil record, and have rarely been applied at the species level. Here, we present a Bayesian framework to estimate extinction rates from the fossil record accounting for age-dependent extinction (ADE). Our approach, unlike previous implementations, explicitly models unobserved species and accounts for the effects of fossil preservation on the observed longevity of sampled lineages. We assess the performance and robustness of our method through extensive simulations and apply it to a fossil data set of terrestrial Carnivora spanning the past 40 myr. We find strong evidence of ADE, as we detect the extinction rate to be highest in young species and declining with increasing species age. For comparison, we apply a recently developed analogous ADE model to a dated phylogeny of extant Carnivora. Although the phylogeny-based analysis also infers ADE, it indicates that the extinction rate, instead, increases with increasing taxon age. The estimated mean species longevity also differs substantially, with the fossil-based analyses estimating 2.0 myr, in contrast to 9.8 myr derived from the phylogeny-based inference. Scrutinizing these discrepancies, we find that both fossil and phylogeny-based ADE models are prone to high error rates when speciation and extinction rates increase or decrease through time. However, analyses of simulated and empirical data show that fossil-based inferences are more

An extraordinary gobioid fish fossil from Southern France.

Directory of Open Access Journals (Sweden)

Christoph Gierl

Full Text Available BACKGROUND: The classification of gobioid fishes is still under discussion. Several lineages, including the Eleotridae and Butidae, remain difficult to characterize because synapomorphies are rare (Eleotridae or have not yet been determined (Butidae. Moreover, the fossil record of these groups is scarce. RESULTS: Exceptionally well-preserved fish fossils with otoliths in situ from uppermost Oligocene sediments (≈23-24 Mio. y. ago in Southern France provide the most in-depth description of a fossil gobioid to date. The species was initially described as Cottus aries Agassiz, then transferred to †Lepidocottus Sauvage, and subsequently assigned to Gobius. Based on a comparative analysis of meristic, osteological and otolith data, this species most likely is a member of the family Butidae. This discovery is important because it represents the first record of a fossil butid fish based on articulated skeletons from Europe. SIGNIFICANCE: The Butidae and Eleotridae are currently distributed in W-Africa, Madagascar, Asia and Australia, but they do not appear in Europe and also not in the Mediterranean Sea. The new results indicate that several species of the Butidae thrived in Europe during the Oligocene and Early Miocene. Similar to the recent Butidae and Eleotridae, these fishes were adapted to a wide range of salinities and thrived in freshwater, brackish and marginal marine habitats. The fossil Butidae disappeared from Europe and the Mediterranean and Paratethys areas during the Early Miocene, due probably to their lack of competitiveness compared to other Gobioidei that radiated during this period of time. In addition, this study documents the great value of otoliths for gobioid systematics.

Neotropical mammal diversity and the Great American Biotic Interchange: spatial and temporal variation in South America's fossil record

Science.gov (United States)

Carrillo, Juan D.; Forasiepi, Analía; Jaramillo, Carlos; Sánchez-Villagra, Marcelo R.

2015-01-01

The vast mammal diversity of the Neotropics is the result of a long evolutionary history. During most of the Cenozoic, South America was an island continent with an endemic mammalian fauna. This isolation ceased during the late Neogene after the formation of the Isthmus of Panama, resulting in an event known as the Great American Biotic Interchange (GABI). In this study, we investigate biogeographic patterns in South America, just before or when the first immigrants are recorded and we review the temporal and geographical distribution of fossil mammals during the GABI. We performed a dissimilarity analysis which grouped the faunal assemblages according to their age and their geographic distribution. Our data support the differentiation between tropical and temperate assemblages in South America during the middle and late Miocene. The GABI begins during the late Miocene (~10–7 Ma) and the putative oldest migrations are recorded in the temperate region, where the number of GABI participants rapidly increases after ~5 Ma and this trend continues during the Pleistocene. A sampling bias toward higher latitudes and younger records challenges the study of the temporal and geographic patterns of the GABI. PMID:25601879

First records of crocodyle and pterosaur tracks in the Upper Jurassic of Portugal

DEFF Research Database (Denmark)

Mateus, Octavio; Milàn, Jesper

2010-01-01

The Upper Jurassic of Portugal has a rich vertebrate fauna well documented from both body and trace fossils. Although the occurrence of crocodyles and pterosaurs is well documented from body fossils, trace fossils from both groups were unknown until now. Here we describe an isolated crocodyle-lik...

The Fossil Calibration Database-A New Resource for Divergence Dating.

Science.gov (United States)

Ksepka, Daniel T; Parham, James F; Allman, James F; Benton, Michael J; Carrano, Matthew T; Cranston, Karen A; Donoghue, Philip C J; Head, Jason J; Hermsen, Elizabeth J; Irmis, Randall B; Joyce, Walter G; Kohli, Manpreet; Lamm, Kristin D; Leehr, Dan; Patané, Josés L; Polly, P David; Phillips, Matthew J; Smith, N Adam; Smith, Nathan D; Van Tuinen, Marcel; Ware, Jessica L; Warnock, Rachel C M

2015-09-01

Fossils provide the principal basis for temporal calibrations, which are critical to the accuracy of divergence dating analyses. Translating fossil data into minimum and maximum bounds for calibrations is the most important-often least appreciated-step of divergence dating. Properly justified calibrations require the synthesis of phylogenetic, paleontological, and geological evidence and can be difficult for nonspecialists to formulate. The dynamic nature of the fossil record (e.g., new discoveries, taxonomic revisions, updates of global or local stratigraphy) requires that calibration data be updated continually lest they become obsolete. Here, we announce the Fossil Calibration Database (http://fossilcalibrations.org), a new open-access resource providing vetted fossil calibrations to the scientific community. Calibrations accessioned into this database are based on individual fossil specimens and follow best practices for phylogenetic justification and geochronological constraint. The associated Fossil Calibration Series, a calibration-themed publication series at Palaeontologia Electronica, will serve as a key pipeline for peer-reviewed calibrations to enter the database. © The Author(s) 2015. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Integrating developmental biology and the fossil record of reptiles.

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Skawiński, Tomasz; Tałanda, Mateusz

2014-01-01

Numerous new discoveries and new research techniques have influenced our understanding of reptile development from a palaeontological perspective. They suggest for example that transition from mineralized to leathery eggshells and from oviparity to viviparity appeared much more often in the evolution of reptiles than was previously thought. Most marine reptiles evolved from viviparous terrestrial ancestors and had probably genetic sex determination. Fossil forms often display developmental traits absent or rare among modern ones such as polydactyly, hyperphalangy, the presence of ribcage armour, reduction of head ornamentation during ontogeny, extreme modifications of vertebral count or a wide range of feather-like structures. Thus, they provide an empirical background for many morphogenetic considerations.

First report of fossil "keratose" demosponges in Phanerozoic carbonates: preservation and 3-D reconstruction.

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Luo, Cui; Reitner, Joachim

2014-06-01

Fossil record of Phanerozoic non-spicular sponges, beside of being important with respect to the lineage evolution per se, could provide valuable references for the investigation of Precambrian ancestral animal fossils. However, although modern phylogenomic studies resolve non-spicular demosponges as the sister group of the remaining spiculate demosponges, the fossil record of the former is extremely sparse or unexplored compared to that of the latter; the Middle Cambrian Vauxiidae Walcott 1920, is the only confirmed fossil taxon of non-spicular demosponges. Here, we describe carbonate materials from Devonian (Upper Givetian to Lower Frasnian) bioherms of northern France and Triassic (Anisian) microbialites of Poland that most likely represent fossil remnants of keratose demosponges. These putative fossils of keratose demosponges are preserved as automicritic clumps. They are morphologically distinguishable from microbial fabrics but similar to other spiculate sponge fossils, except that the skeletal elements consist of fibrous networks instead of assembled spicules. Consistent with the immunological behavior of sponges, these fibrous skeletons often form a rim at the edge of the automicritic aggregate, separating the inner part of the aggregate from foreign objects. To confirm the architecture of these fibrous networks, two fossil specimens and a modern thorectid sponge for comparison were processed for three-dimensional (3-D) reconstruction using serial grinding tomography. The resulting fossil reconstructions are three-dimensionally anastomosing, like modern keratose demosponges, but their irregular and nonhierarchical meshes indicate a likely verongid affinity, although a precise taxonomic conclusion cannot be made based on the skeletal architecture alone. This study is a preliminary effort, but an important start to identify fossil non-spicular demosponges in carbonates and to re-evaluate their fossilization potential.

Precambrian evolution and the rock record

Science.gov (United States)

Awramik, S.

1985-01-01

The Precambrian time which refers to geological time prior to the first appearance of animals with mineralized hard parts was investigated. Best estimates for this event are around 570 million years ago. Because the rock record begins some 3,800 million years ago the Precambrian encompasses about 84% of geologic time. The fossil record for this immense span of time is dominated by prokaryotes and the sedimentary structures produced by them. The first fossil remains that are considered eukaryotic are found in 1,000 million year old rocks. The first animals may be as old as 700 million years. The fossil records of the first 84% of the Earth's history are collected and described.

Fossil Explorers

Science.gov (United States)

Moran, Sean; McLaughlin, Cheryl; MacFadden, Bruce; Jacobbe, Elizabeth; Poole, Michael

2015-01-01

Many young learners are fascinated with fossils, particularly charismatic forms such as dinosaurs and giant sharks. Fossils provide tangible, objective evidence of life that lived millions of years ago. They also provide a timescale of evolution not typically appreciated by young learners. Fossils and the science of paleontology can, therefore,…

New Mesozoic and Cenozoic fossils from Ecuador: Invertebrates, vertebrates, plants, and microfossils

Science.gov (United States)

Cadena, Edwin A.; Mejia-Molina, Alejandra; Brito, Carla M.; Peñafiel, Sofia; Sanmartin, Kleber J.; Sarmiento, Luis B.

2018-04-01

Ecuador is well known for its extensive extant biodiversity, however, its paleobiodiversity is still poorly explored. Here we report seven new Mesozoic and Cenozoic fossil localities from the Pacific coast, inter-Andean depression and Napo basin of Ecuador, including vertebrates, invertebrates, plants, and microfossils. The first of these localities is called El Refugio, located near the small town of Chota, Imbabura Province, from where we report several morphotypes of fossil leaves and a mycetopodid freshwater mussel of the Upper Miocene Chota Formation. A second site is also located near the town of Chota, corresponding to potentially Pleistocene to Holocene lake deposits from which we report the occurrence of leaves and fossil diatoms. A third locality is at the Pacific coast of the country, near Rocafuerte, a town in Esmeraldas Province, from which we report a late Miocene palm leaf. We also report the first partially articulated skull with teeth from a Miocene scombridid (Mackerels) fish from El Cruce locality, and completely preserved seeds from La Pila locality, both sites from Manabí Province. Two late Cretaceous fossil sites from the Napo Province, one near Puerto Napo showing a good record of fossil shrimps and a second near the town of Loreto shows the occurrence of granular amber and small gymnosperms seeds and cuticles. All these new sites and fossils show the high potential of the sedimentary sequences and basins of Ecuador for paleontological studies and for a better understanding of the fossil record of the country and northern South America.

Atmospheric methane isotopic record favors fossil sources flat in 1980s and 1990s with recent increase

Science.gov (United States)

Rice, Andrew L.; Butenhoff, Christopher L.; Teama, Doaa G.; Röger, Florian H.; Khalil, M. Aslam K.; Rasmussen, Reinhold A.

2016-09-01

Observations of atmospheric methane (CH4) since the late 1970s and measurements of CH4 trapped in ice and snow reveal a meteoric rise in concentration during much of the twentieth century. Since 1750, levels of atmospheric CH4 have more than doubled to current globally averaged concentration near 1,800 ppb. During the late 1980s and 1990s, the CH4 growth rate slowed substantially and was near or at zero between 1999 and 2006. There is no scientific consensus on the drivers of this slowdown. Here, we report measurements of the stable isotopic composition of atmospheric CH4 (13C/12C and D/H) from a rare air archive dating from 1977 to 1998. Together with more modern records of isotopic atmospheric CH4, we performed a time-dependent retrieval of methane fluxes spanning 25 y (1984-2009) using a 3D chemical transport model. This inversion results in a 24 [18, 27] Tg y-1 CH4 increase in fugitive fossil fuel emissions since 1984 with most of this growth occurring after year 2000. This result is consistent with some bottom-up emissions inventories but not with recent estimates based on atmospheric ethane. In fact, when forced with decreasing emissions from fossil fuel sources our inversion estimates unreasonably high emissions in other sources. Further, the inversion estimates a decrease in biomass-burning emissions that could explain falling ethane abundance. A range of sensitivity tests suggests that these results are robust.

Corrected placement of Mus-Rattus fossil calibration forces precision in the molecular tree of rodents

OpenAIRE

Kimura, Yuri; Hawkins, Melissa T. R.; McDonough, Molly M.; Jacobs, Louis L.; Flynn, Lawrence J.

2015-01-01

Time calibration derived from the fossil record is essential for molecular phylogenetic and evolutionary studies. Fossil mice and rats, discovered in the Siwalik Group of Pakistan, have served as one of the best-known fossil calibration points in molecular phylogenic studies. Although these fossils have been widely used as the 12 Ma date for the Mus/Rattus split or a more basal split, conclusive paleontological evidence for the nodal assignments has been absent. This study analyzes newly reco...

A rich Pleistocene-Holocene avifaunal sequence from Te Waka no. 1 : terrestrial fossil vertebrate faunas from inland Hawke's Bay, North Island, New Zealand. Part 2

International Nuclear Information System (INIS)

Worthy, T.H.; Holdaway, R.N.; Alloway, B.V.; Jones, J.; Winn, J.; Turner, D.

2002-01-01

The results of 13 m 2 of new excavations in the rockshelter called Te Waka no. 1, 900 m above sea level in inland Hawke's Bay, North Island, New Zealand, are presented. The site is shown to have an unparalleled continuous faunal record in sediments about 3 m deep that spans the period from the Kawakawa eruption 22,600 14 C yrs BP to the present. Good temporal control is afforded by clear stratigraphy, three obvious tephras (Taupo Ignimbrite, one unidentified, Kawakawa Tephra (Oruanui Ignimbrite)), seven AMS radiocarbon ages, and one uranium-series age. Three frog species, a tuatara, five lizards, 42 birds, and three bats are represented in the 2490 identified bones from the combined faunas from W.H. Hartree's late 1950s and our 1999-2000 excavations. The fauna is interpreted as being mainly derived from the prey remains of Falco novaeseelandiae; it includes the first fossil records of Garrodia nereis and Charadrius bicinctus from the North Island. The presence in the fossil avifauna of species that live only in shrubland or forest indicates that such vegetation was present on Te Waka between 22,600 14 C yrs BP and the Late Glacial Maximum (LGM, 18,000 14 C yrs BP). Pterodroma cookii ceased to breed on Te Waka over the LGM. The absence of this species (which nests solely under forest), the lack of forest passerines, and the presence of species characteristic of open vegetation indicate a substantial loss of vegetation around the site at that time. The sedimentary and faunal record indicate that the area was reafforested about 14,000 14 C yrs BP. (author). 75 refs., 9 figs., 6 tabs

Dental development in living and fossil orangutans.

Science.gov (United States)

Smith, Tanya M

2016-05-01

Numerous studies have investigated molar development in extant and fossil hominoids, yet relatively little is known about orangutans, the only great ape with an extensive fossil record. This study characterizes aspects of dental development, including cuspal enamel daily secretion rate, long-period line periodicities, cusp-specific molar crown formation times and extension rates, and initiation and completion ages in living and fossil orangutan postcanine teeth. Daily secretion rate and periodicities in living orangutans are similar to previous reports, while crown formation times often exceed published values, although direct comparisons are limited. One wild Bornean individual died at 4.5 years of age with fully erupted first molars (M1s), while a captive individual and a wild Sumatran individual likely erupted their M1s around five or six years of age. These data underscore the need for additional samples of orangutans of known sex, species, and developmental environment to explore potential sources of variation in molar emergence and their relationship to life history variables. Fossil orangutans possess larger crowns than living orangutans, show similarities in periodicities, and have faster daily secretion rate, longer crown formation times, and slower extension rates. Molar crown formation times exceed reported values for other fossil apes, including Gigantopithecus blacki. When compared to African apes, both living and fossil orangutans show greater cuspal enamel thickness values and periodicities, resulting in longer crown formation times and slower extension rates. Several of these variables are similar to modern humans, representing examples of convergent evolution. Molar crown formation does not appear to be equivalent among extant great apes or consistent within living and fossil members of Pongo or Homo. Copyright © 2016 The Author. Published by Elsevier Ltd.. All rights reserved.

Terrestrial Origin of Viviparity in Mesozoic Marine Reptiles Indicated by Early Triassic Embryonic Fossils

OpenAIRE

Motani, Ryosuke; Jiang, Da-yong; Tintori, Andrea; Rieppel, Olivier; Chen, Guan-bao

2014-01-01

Viviparity in Mesozoic marine reptiles has traditionally been considered an aquatic adaptation. We report a new fossil specimen that strongly contradicts this traditional interpretation. The new specimen contains the oldest fossil embryos of Mesozoic marine reptile that are about 10 million years older than previous such records. The fossil belongs to Chaohusaurus (Reptilia, Ichthyopterygia), which is the oldest of Mesozoic marine reptiles (ca. 248 million years ago, Early Triassic). This exc...

Flood rich periods, flood poor periods and the need to look beyond instrumental records

Science.gov (United States)

Lane, S. N.

2009-04-01

For many, the later 20th Century and early 21st Century has become synonymous with a growing experience of flood risk. Scientists, politicians and the media have ascribed this to changing climate and there are good hypothetical reasons for human-induced climate change to be impacting upon the magnitude and frequency of extreme weather events. In this paper, I will interrogate this claim more carefully, using the UK's instrumental records of river flow, most of which begin after 1960, but a smaller number of which extend back into the 19th Century. Those records that extent back to the 19th Century suggest that major flood events tend to cluster into periods that are relatively flood rich and relatively flood poor, most notably in larger drainage basins: i.e. there is a clear scale issue. The timing (inset, duration, termination) of these periods varies systematically by region although there is a marked flood poor period for much of the UK during the late 1960s, 1970s and 1980s. It follows that at least some of the current experience of flooding, including why it has taken so many policy-makers and flood victims by surprise, may reflect a transition from a flood poor to a flood rich period, exacerbated by possible climate change impacts. These results point to the need to rethink how we think through what drives flood risk. First, it points to the need to look at some of the fundamental oscillations in core atmospheric drivers, such as the North Atlantic Multidecadal Oscillation, in explaining what drives flood risk. Consideration of precipitation, as opposed to river flow, is more advanced in this respect, and those of us working in rivers need to engage much more thoughtfully with atmospheric scientists. Second, it points to the severe inadequacies in using records of only a few decades duration. Even where these are pooled across adjacent sub-catchments, there is likely to be a severe bias in the estimation of flood return periods when we look at instrumental

Pollen-vegetation richness and diversity relationships in the tropics

NARCIS (Netherlands)

Gosling, W.D.; Julier, A.C.M.; Adu-Bredu, S.; Djagbletey, G.D.; Fraser, W.T.; Jardine, P.E.; Lomax, B.H.; Malhi, Y.; Manu, E.A.; Mayle, F.E.; Moore, S.

Tracking changes in biodiversity through time requires an understanding of the relationship between modern diversity and how this diversity is preserved in the fossil record. Fossil pollen is one way in which past vegetation diversity can be reconstructed. However, there is limited understanding of

Fossilization History of Fossil Resin from Jambi Province (Sumatra, Indonesia Based on Physico-Chemical Studies

Directory of Open Access Journals (Sweden)

Beata Naglik

2018-03-01

Full Text Available A unique specimen of fossil resin originating from the Dipterocarpaceae tree family found in Miocene brown coal deposits in Jambi Province (Sumatra, Indonesia was investigated via microscopic observations, microhardness testing and infrared and Raman spectroscopic methods. Its form is rare in nature, being an aggregate of three varieties of resin differing in colour, transparency and internal structure. This suggests the formation of the resins at different stages. Further alteration processes, including fossilization and maturation of the resin in a swamp environment resulted in stepwise aromatization of the cyclohexane ring in steroids and cross-linking through formation of ester bonds as well as carbon–carbon bonds between steroid molecules. The various environmental and geological conditions affecting the formation processes of the resins were recorded in their physico-chemical properties. Additionally, heating conditions accelerated by volcanism were proposed as a factor determining the maturation grade of the resin.

A minute fossil phoretic mite recovered by phase-contrast X-ray computed tomography.

Science.gov (United States)

Dunlop, Jason A; Wirth, Stefan; Penney, David; McNeil, Andrew; Bradley, Robert S; Withers, Philip J; Preziosi, Richard F

2012-06-23

High-resolution phase-contrast X-ray computed tomography (CT) reveals the phoretic deutonymph of a fossil astigmatid mite (Acariformes: Astigmata) attached to a spider's carapace (Araneae: Dysderidae) in Eocene (44-49 Myr ago) Baltic amber. Details of appendages and a sucker plate were resolved, and the resulting three-dimensional model demonstrates the potential of tomography to recover morphological characters of systematic significance from even the tiniest amber inclusions without the need for a synchrotron. Astigmatids have an extremely sparse palaeontological record. We confirm one of the few convincing fossils, potentially the oldest record of Histiostomatidae. At 176 µm long, we believe this to be the smallest arthropod in amber to be CT-scanned as a complete body fossil, extending the boundaries for what can be recovered using this technique. We also demonstrate a minimum age for the evolution of phoretic behaviour among their deutonymphs, an ecological trait used by extant species to disperse into favourable environments. The occurrence of the fossil on a spider is noteworthy, as modern histiostomatids tend to favour other arthropods as carriers.

A minute fossil phoretic mite recovered by phase-contrast X-ray computed tomography

Science.gov (United States)

Dunlop, Jason A.; Wirth, Stefan; Penney, David; McNeil, Andrew; Bradley, Robert S.; Withers, Philip J.; Preziosi, Richard F.

2012-01-01

High-resolution phase-contrast X-ray computed tomography (CT) reveals the phoretic deutonymph of a fossil astigmatid mite (Acariformes: Astigmata) attached to a spider's carapace (Araneae: Dysderidae) in Eocene (44–49 Myr ago) Baltic amber. Details of appendages and a sucker plate were resolved, and the resulting three-dimensional model demonstrates the potential of tomography to recover morphological characters of systematic significance from even the tiniest amber inclusions without the need for a synchrotron. Astigmatids have an extremely sparse palaeontological record. We confirm one of the few convincing fossils, potentially the oldest record of Histiostomatidae. At 176 µm long, we believe this to be the smallest arthropod in amber to be CT-scanned as a complete body fossil, extending the boundaries for what can be recovered using this technique. We also demonstrate a minimum age for the evolution of phoretic behaviour among their deutonymphs, an ecological trait used by extant species to disperse into favourable environments. The occurrence of the fossil on a spider is noteworthy, as modern histiostomatids tend to favour other arthropods as carriers. PMID:22072283

Parasites in the fossil record: a Cretaceous fauna with isopod-infested decapod crustaceans, infestation patterns through time, and a new ichnotaxon.

Directory of Open Access Journals (Sweden)

Adiël A Klompmaker

Full Text Available Parasites are common in modern ecosystems and are also known from the fossil record. One of the best preserved and easily recognisable examples of parasitism in the fossil record concerns isopod-induced swellings in the branchial chamber of marine decapod crustaceans. However, very limited quantitative data on the variability of infestation percentages at the species, genus, and family levels are available. Here we provide this type of data for a mid-Cretaceous (upper Lower Cretaceous, upper Albian reef setting at Koskobilo, northern Spain, on the basis of 874 specimens of anomurans and brachyurans. Thirty-seven specimens (4.2%, arranged in ten species, are infested. Anomurans are more heavily infested than brachyurans, variability can be high within genera, and a relationship may exist between the number of specimens and infestation percentage per taxon, possibly suggesting host-specificity. We have also investigated quantitative patterns of infestation through geological time based on 88 infested species (25 anomurans, 55 brachyurans, seven lobsters, and one shrimp, to show that the highest number of infested species can be found in the Late Jurassic, also when corrected for the unequal duration of epochs. The same Late Jurassic peak is observed for the percentage of infested decapod species per epoch. This acme is caused entirely by infested anomurans and brachyurans. Biases (taphonomic and otherwise and causes of variability with regard to the Koskobilo assemblage and infestation patterns through time are discussed. Finally, a new ichnogenus and -species, Kanthyloma crusta, are erected to accommodate such swellings or embedment structures (bioclaustrations.

The consequences of time averaging for measuring temporal species turnover in the fossil record

Science.gov (United States)

Tomašových, Adam; Kidwell, Susan

2010-05-01

Modeling time averaging effects with simple simulations allows us to evaluate the magnitude of change in temporal species turnover that is expected to occur in long (paleoecological) time series with fossil assemblages. Distinguishing different modes of metacommunity dynamics (such as neutral, density-dependent, or trade-off dynamics) with time-averaged fossil assemblages requires scaling-up time-averaging effects because the decrease in temporal resolution and the decrease in temporal inter-sample separation (i.e., the two main effects of time averaging) substantially increase community stability relative to assemblages without or with weak time averaging. Large changes in temporal scale that cover centuries to millennia can lead to unprecedented effects on temporal rate of change in species composition. Temporal variation in species composition monotonically decreases with increasing duration of time-averaging in simulated fossil assemblages. Time averaging is also associated with the reduction of species dominance owing to the temporal switching in the identity of dominant species. High degrees of time averaging can cause that community parameters of local fossil assemblages converge to parameters of metacommunity rather that to parameters of individual local non-averaged communities. We find that the low variation in species composition observed among mollusk and ostracod subfossil assemblages can be explained by time averaging alone, and low temporal resolution and reduced temporal separation among assemblages in time series can thus explain a substantial part of the reduced variation in species composition relative to unscaled predictions of neutral model (i.e., species do not differ in birth, death, and immigration rates on per capita basis). The structure of time-averaged assemblages can thus provide important insights into processes that act over larger temporal scales, such as evolution of niches and dispersal, range-limit dynamics, taxon cycles, and

Fossil Flora of the John Day Basin, Oregon

Science.gov (United States)

Knowlton, Frank Hall

1902-01-01

expedition into this region made under the auspices of the University of California. When these plants were submitted to me for study, it was thought possible to present their description, together with a revision of our knowledge of the previously known forms, within a space sufficiently small to permit the publication of the matter as an appendix to a paper on the general geology of the area, then in preparation by Dr. Merriam. But it soon became apparent that this could not be adequately done within the space available, and a short preliminary report was prepared for and published by Dr. Merriam. The results of a complete restudy of all available fossil plant material from the John Day Basin are now presented. I wish to record my great indebtedness to Dr. Merriam, who not only accompanied me at a considerable personal sacrifice on a trip through the region in 1901, but placed unreservedly at my disposal all material bearing in any way on the problem then in the paleontological museum of the University of California. To Dr. Arthur Hollick I am indebted for the loan of all material from the John Day region belonging to Columbia University, and now deposited in the New York Botanical Garden at Bronx Park. This material, together with the rich collections belonging to the United States National Museum, represents practically all now known to have come from the John Day Basin.

The fossil record of evolution: Analysis of extinction

Science.gov (United States)

Raup, D. M.

1986-01-01

There is increasing evidence that events in space have had direct effects on Earth history and on the history of life on Earth. Nowhere is this more evident than in mass extinction. The biosphere has undergone repeated devastation caused by relatively short-lived environmental stress, with species kill rates up to 80 and 95%. For five of the mass extinctions, geochemical or other evidence was reported suggesting large body impact as the cause of the environmental stress producing the extinctions. It was argued on statistical ground that the major extinction events are uniformly periodic in geological time. If it is true that large body impact is a principal cause of mass extinctions and if the periodicity is real, than a cosmic driving mechanism is inescapable. Paleontological data sets were developed which detail the ranges in geological time of about 4,000 families and 25,000 genera of fossil marine organisms. Analyses to date have concentrated on the most recent 250 million years. Associated with these studies are analyses of other aspects of Earth history which may have signatures indicative of extraterrestrial effects.

Calcium-phosphate biomineralization induced by alkaline phosphatase activity in Escherichia coli: localization, kinetics and potential signatures in the fossil record

Science.gov (United States)

Cosmidis, Julie; Benzerara, Karim; Guyot, François; Skouri-Panet, Fériel; Duprat, Elodie; Férard, Céline; Guigner, Jean-Michel; Babonneau, Florence; Coelho, Cristina

2015-12-01

Bacteria are thought to play an important role in the formation of calcium-phosphate minerals composing marine phosphorites, as supported by the common occurrence of fossil microbes in these rocks. Phosphatase enzymes may play a key role in this process. Indeed, they may increase the supersaturation with respect to Ca-phosphates by releasing orthophosphate ions following hydrolysis of organic phosphorus. However, several questions remain unanswered about the cellular-level mechanisms involved in this model, and its potential signatures in the mineral products. We studied Ca-phosphate precipitation by different strains of Escherichia coli which were genetically modified to differ in the abundance and cellular localization of the alkaline phosphatase (PHO A) produced. The mineral precipitated by either E. coli or purified PHO A was invariably identified as a carbonate-free non-stoichiometric hydroxyapatite. However, the bacterial precipitates could be discriminated from the ones formed by purified PHO A at the nano-scale. PHO A localization was shown to influence the pattern of Ca-phosphate nucleation and growth. Finally, the rate of calcification was proved to be consistent with the PHO A enzyme kinetics. Overall, this study provides mechanistic keys to better understand phosphogenesis in the environment, and experimental references to better interpret the microbial fossil record in phosphorites.

The Fossile Episode

OpenAIRE

Hassler, John; Sinn, Hans-Werner

2012-01-01

We build a two-sector dynamic general equilibrium model with one-sided substitutability between fossil carbon and biocarbon. One shock only, the discovery of the technology to use fossil fuels, leads to a transition from an inital pre-industrial phase to three following phases: a pure fossil carbon phase, a mixed fossil and biocarbon phase and an absorbing biocarbon phase. The increased competition for biocarbon during phase 3 and 4 leads to increasing food prices. We provide closed form expr...

The Fossil Episode

OpenAIRE

John Hassler; Hans-Werner Sinn

2012-01-01

We build a two-sector dynamic general equilibrium model with one-sided substitutability between fossil carbon and biocarbon. One shock only, the discovery of the technology to use fossil fuels, leads to a transition from an initial pre-industrial phase to three following phases: a pure fossil carbon phase, a mixed fossil and biocarbon phase and an absorbing biocarbon phase. The increased competition for biocarbon during phase 3 and 4 leads to increasing food prices. We provide closed form exp...

Fossil nutlets of Boraginaceae from the continental Eocene of Hamada of Méridja (southwestern Algeria): The first fossil of the Borage family in Africa.

Science.gov (United States)

Hammouda, Sid Ahmed; Weigend, Maximilian; Mebrouk, Fateh; Chacón, Juliana; Bensalah, Mustapha; Ensikat, Hans-Jürgen; Adaci, Mohammed

2015-12-01

The Paleogene deposits of the Hamada of Méridja, southwestern Algeria, are currently dated as lower-to-middle Eocene in age based on fossil gastropods and charophytes. Here we report the presence of fruits that can be assigned to the Boraginaceae s.str., apparently representing the first fossil record for this family in Africa, shedding new light on the historical biogeography of this group. Microscopic studies of the fossil nutlets were carried out and compared to extant Boraginaceae nutlets, and to types reported in the literature for this family. The fossils are strikingly similar in general size and morphology, particularly in the finer details of the attachment scar and ornamentation, to nutlets of extant representatives of the Boraginaceae tribe Echiochileae, and especially the genus Ogastemma. We believe that these nutlets represent an extinct member of this lineage. The Ogastemma-like fossils indicate that the Echiochileae, which are most diverse in northern Africa and southwestern Asia, have a long history in this region, dating back to the Eocene. This tribe corresponds to the basal-most clade in Boraginaceae s.str., and the fossils described here agree well with an assumed African origin of the family and the Boraginales I, providing an important additional calibration point for dating the phylogenies of this clade. © 2015 Botanical Society of America.

Putting fossils on the map: Applying a geographical information system to heritage resources

Directory of Open Access Journals (Sweden)

Merrill van der Walt

2015-11-01

Full Text Available A geographical information system (GIS database was compiled of Permo-Triassic tetrapod fossils from the Karoo Supergoup in South African museum collections. This database is the first of its kind and has great time applicability for understanding tetrapod biodiversity change though time more than 200 million years ago. Because the museum catalogues all differed in recorded information and were not compliant with field capture requirements, this information had to be standardised to a format that could be utilised for archival and research application. Our paper focuses on the processes involved in building the GIS project, capturing metadata on fossil collections and formulating future best practices. The result is a multi-layered GIS database of the tetrapod fossil record of the Beaufort Group of South Africa for use as an accurate research tool in palaeo- and geoscience research with applications for ecology, ecosystems, stratigraphy and basin development.

The first fossil salmonfly (Insecta: Plecoptera: Pteronarcyidae), back to the Middle Jurassic.

Science.gov (United States)

Cui, Yingying; Béthoux, Olivier; Kondratieff, Boris; Shih, Chungkun; Ren, Dong

2016-10-18

The fossil record of Plecoptera (stoneflies) is considered relatively complete, with stem-groups of each of the three major lineages, viz. Antarctoperlaria, Euholognatha and Systellognatha (and some of their families) represented in the Mesozoic. However, the family Pteronarcyidae (the salmonflies; including two genera, Pteronarcys and Pteronarcella) has no fossil record to date, and the family has been suggested to have diverged recently. In this paper, we report on a set of specimens belonging to a new fossil species of stonefly, discovered from the Middle Jurassic Daohugou locality (China). Our comparative analysis of wing venation and body characters demonstrates that the new species belongs to the Pteronarcyidae, and is more closely related to Pteronarcys than to Pteronarcella. However, it differs from all known species of the former genus. It is therefore assigned to a new genus and named Pteroliriope sinitshenkovae gen. et sp. nov. under the traditional nomenclatural procedure. The cladotypic nomenclatural procedure is also employed, with the resulting combination Pteroliriope nec Pteronarcys sinitshenkovae sp. nov. The first discovery of a fossil member of the Pteronarcyidae demonstrates that the corresponding lineage is not a very recent offshoot but was already present ca. 165 million years ago. This discovery concurs with the view that divergence of most stonefly families took place very early, probably in the Triassic, or even in the Permian. This contribution demonstrates the need for (re-)investigations of the systematics of fossil stoneflies to refine divergence date estimates for Plecoptera lineages.

A dating success story: genomes and fossils converge on placental mammal origins

Directory of Open Access Journals (Sweden)

Goswami Anjali

2012-08-01

Full Text Available Abstract The timing of the placental mammal radiation has been a source of contention for decades. The fossil record of mammals extends over 200 million years, but no confirmed placental mammal fossils are known prior to 64 million years ago, which is approximately 1.5 million years after the Cretaceous-Paleogene (K-Pg mass extinction that saw the end of non-avian dinosaurs. Thus, it came as a great surprise when the first published molecular clock studies suggested that placental mammals originated instead far back in the Cretaceous, in some cases doubling divergence estimates based on fossils. In the last few decades, more than a hundred new genera of Mesozoic mammals have been discovered, and molecular divergence studies have grown from simple clock-like models applied to a few genes to sophisticated analyses of entire genomes. Yet, molecular and fossil-based divergence estimates for placental mammal origins have remained remote, with knock-on effects for macro-scale reconstructions of mammal evolution. A few recent molecular studies have begun to converge with fossil-based estimates, and a new phylogenomic study in particular shows that the palaeontological record was mostly correct; most placental mammal orders diversified after the K-Pg mass extinction. While a small gap still remains for Late Cretaceous supraordinal divergences, this study has significantly improved the congruence between molecular and palaeontological data and heralds a broader integration of these fields of evolutionary science.

Uranium concentration in fossils

International Nuclear Information System (INIS)

Okano, J.; Uyeda, C.

1988-01-01

Recently it is known that fossil bones tend to accumulate uranium. The uranium concentration, C u in fossils has been measured so far by γ ray spectroscopy or by fission track method. The authors applied secondary ion mass spectrometry, SIMS, to detect the uranium in fossil samples. The purpose of this work is to investigate the possibility of semi-quantitative analyses of uranium in fossils, and to study the correlation between C u and the age of fossil bones. The further purpose of this work is to apply SIMS to measure the distribution of C u in fossil teeth

A Total-Evidence Approach to Dating with Fossils, Applied to the Early Radiation of the Hymenoptera

Science.gov (United States)

Ronquist, Fredrik; Klopfstein, Seraina; Vilhelmsen, Lars; Schulmeister, Susanne; Murray, Debra L.; Rasnitsyn, Alexandr P.

2012-01-01

Abstract Phylogenies are usually dated by calibrating interior nodes against the fossil record. This relies on indirect methods that, in the worst case, misrepresent the fossil information. Here, we contrast such node dating with an approach that includes fossils along with the extant taxa in a Bayesian total-evidence analysis. As a test case, we focus on the early radiation of the Hymenoptera, mostly documented by poorly preserved impression fossils that are difficult to place phylogenetically. Specifically, we compare node dating using nine calibration points derived from the fossil record with total-evidence dating based on 343 morphological characters scored for 45 fossil (4--20 complete) and 68 extant taxa. In both cases we use molecular data from seven markers (∼5 kb) for the extant taxa. Because it is difficult to model speciation, extinction, sampling, and fossil preservation realistically, we develop a simple uniform prior for clock trees with fossils, and we use relaxed clock models to accommodate rate variation across the tree. Despite considerable uncertainty in the placement of most fossils, we find that they contribute significantly to the estimation of divergence times in the total-evidence analysis. In particular, the posterior distributions on divergence times are less sensitive to prior assumptions and tend to be more precise than in node dating. The total-evidence analysis also shows that four of the seven Hymenoptera calibration points used in node dating are likely to be based on erroneous or doubtful assumptions about the fossil placement. With respect to the early radiation of Hymenoptera, our results suggest that the crown group dates back to the Carboniferous, ∼309 Ma (95% interval: 291--347 Ma), and diversified into major extant lineages much earlier than previously thought, well before the Triassic. [Bayesian inference; fossil dating; morphological evolution; relaxed clock; statistical phylogenetics.] PMID:22723471

Modes of fossil preservation

Science.gov (United States)

Schopf, J.M.

1975-01-01

The processes of geologic preservation are important for understanding the organisms represented by fossils. Some fossil differences are due to basic differences in organization of animals and plants, but the interpretation of fossils has also tended to be influenced by modes of preservation. Four modes of preservation generally can be distinguished: (1) Cellular permineralization ("petrifaction") preserves anatomical detail, and, occasionally, even cytologic structures. (2) Coalified compression, best illustrated by structures from coal but characteristic of many plant fossils in shale, preserves anatomical details in distorted form and produces surface replicas (impressions) on enclosing matrix. (3) Authigenic preservation replicates surface form or outline (molds and casts) prior to distortion by compression and, depending on cementation and timing, may intergrade with fossils that have been subject to compression. (4) Duripartic (hard part) preservation is characteristic of fossil skeletal remains, predominantly animal. Molds, pseudomorphs, or casts may form as bulk replacements following dissolution of the original fossil material, usually by leaching. Classification of the kinds of preservation in fossils will aid in identifying the processes responsible for modifying the fossil remains of both animals and plants. ?? 1975.

Global patterns of insect diversification: towards a reconciliation of fossil and molecular evidence?

Science.gov (United States)

Condamine, Fabien L; Clapham, Matthew E; Kergoat, Gael J

2016-01-18

Macroevolutionary studies of insects at diverse taxonomic scales often reveal dynamic evolutionary patterns, with multiple inferred diversification rate shifts. Responses to major past environmental changes, such as the Cretaceous Terrestrial Revolution, or the development of major key innovations, such as wings or complete metamorphosis are usually invoked as potential evolutionary triggers. However this view is partially contradicted by studies on the family-level fossil record showing that insect diversification was relatively constant through time. In an attempt to reconcile both views, we investigate large-scale insect diversification dynamics at family level using two distinct types of diversification analyses on a molecular timetree representing ca. 82% of the extant families, and reassess the insect fossil diversity using up-to-date records. Analyses focusing on the fossil record recovered an early burst of diversification, declining to low and steady rates through time, interrupted by extinction events. Phylogenetic analyses showed that major shifts of diversification rates only occurred in the four richest holometabolous orders. Both suggest that neither the development of flight or complete metamorphosis nor the Cretaceous Terrestrial Revolution environmental changes induced immediate changes in diversification regimes; instead clade-specific innovations likely promoted the diversification of major insect orders.

Investments in Fossil Energy Technology: How the Government's Fossil Energy R&D Program Has Made a Difference

Science.gov (United States)

1997-03-01

America has the technological capacity to change its energy future. There is no reason, for example, why our nation must continue following a path of rising oil imports when billions of barrels of crude oil remain in domestic oil fields. There is no reason why we cannot continue to use our abundant supplies of high-value, low-cost coal when we have the scientific know-how to remove virtually all of its pollutants and reduce greenhouse gas emissions. There is no reason why we cannot turn increasingly to clean-burning natural gas and tap the huge supplies we know exist within our borders. We remain a nation rich in the fuels that have powered economic growth. Today 85 percent of the energy we use to heat our homes and businesses, generate our electricity, and fuel our vehicles comes from coal, petroleum and natural gas. As we move toward a new century, the contributions of these fuels will grow. By 2015, the United States is likely to require nearly 20 percent more energy than it uses today, and fossil fuels are projected to supply almost 88 percent of the energy Americans will consume. We have the scientific know-how to continue using our fossil fuel wealth without fear of environmental damage or skyrocketing costs. The key is technology - developing cutting edge concepts that are beyond the private sector's current capabilities. Some of the most important innovations in America's energy industry are the results of investments in the Federal government's fossil energy research and development programs. Today, our air and water are cleaner, our economy is stronger, and our industries are more competitive in the global market because these programs have produced results. This booklet summarizes many of these achievements. It is not a comprehensive list by any means. Still, it provides solid evidence that the taxpayers' investment in government fossil energy research has paid real and measurable dividends.

Present knowledge on the fossil mammals record from Chile; Estado actual del conocimiento de los mamiferos fosiles de Chile

Energy Technology Data Exchange (ETDEWEB)

Canto, J.; Yanez, J.; Rovira, J.

2010-07-01

An updated revision is presented regarding fossil mammals of aquatic and terrestrial environments. This update includes up to year 2008. Those registrations of doubtful assignation or that couldn't be confirmed were not considered in this review. These new registrations are classified in four groups of time that extend from the Late Eocene-Early Oligocene to the Pleistocene-Recent. The evidence shows that the greatest quantity of fossils are concentrated from the Early Miocene to the Middle Miocene reaching 37 (41.5%) genus of a total of 77 and 54 (49.5%) fossil species of a total of 89. It is observed a significant increase in works devoted to paleontology of mammal fossils in Chile between 1981-2008. (Author)

Multiple Nebular Gas Reservoirs Recorded by Oxygen Isotope Variation in a Spinel-Rich CAI in CO3 MIL 090019

Science.gov (United States)

Simon, J. I.; Simon, S. B.; Nguyen, A. N.; Ross, D. K.; Messenger, S.

2017-07-01

We conducted NanoSIMS ion imaging studies of a primitive spinel-rich CAI from the MIL 090019 CO3 chondrite. It records radial O-isotopic heterogeneity among multiple occurrences of the same mineral, reflecting distinct nebular O-isotopic reservoirs.

Trace Fossil Evidence of Trematode-Bivalve Parasite-Host Interactions in Deep Time.

Science.gov (United States)

Huntley, John Warren; De Baets, Kenneth

2015-01-01

Parasitism is one of the most pervasive phenomena amongst modern eukaryotic life and yet, relative to other biotic interactions, almost nothing is known about its history in deep time. Digenean trematodes (Platyhelminthes) are complex life cycle parasites, which have practically no body fossil record, but induce the growth of characteristic malformations in the shells of their bivalve hosts. These malformations are readily preserved in the fossil record, but, until recently, have largely been overlooked by students of the fossil record. In this review, we present the various malformations induced by trematodes in bivalves, evaluate their distribution through deep time in the phylogenetic and ecological contexts of their bivalve hosts and explore how various taphonomic processes have likely biased our understanding of trematodes in deep time. Trematodes are known to negatively affect their bivalve hosts in a number of ways including castration, modifying growth rates, causing immobilization and, in some cases, altering host behaviour making the host more susceptible to their own predators. Digeneans are expected to be significant agents of natural selection. To that end, we discuss how bivalves may have adapted to their parasites via heterochrony and suggest a practical methodology for testing such hypotheses in deep time. Copyright © 2015 Elsevier Ltd. All rights reserved.

Fossil preservation and the stratigraphic ranges of taxa

Science.gov (United States)

Foote, M.; Raup, D. M.

1996-01-01

The incompleteness of the fossil record hinders the inference of evolutionary rates and patterns. Here, we derive relationships among true taxonomic durations, preservation probability, and observed taxonomic ranges. We use these relationships to estimate original distributions of taxonomic durations, preservation probability, and completeness (proportion of taxa preserved), given only the observed ranges. No data on occurrences within the ranges of taxa are required. When preservation is random and the original distribution of durations is exponential, the inference of durations, preservability, and completeness is exact. However, reasonable approximations are possible given non-exponential duration distributions and temporal and taxonomic variation in preservability. Thus, the approaches we describe have great potential in studies of taphonomy, evolutionary rates and patterns, and genealogy. Analyses of Upper Cambrian-Lower Ordovician trilobite species, Paleozoic crinoid genera, Jurassic bivalve species, and Cenozoic mammal species yield the following results: (1) The preservation probability inferred from stratigraphic ranges alone agrees with that inferred from the analysis of stratigraphic gaps when data on the latter are available. (2) Whereas median durations based on simple tabulations of observed ranges are biased by stratigraphic resolution, our estimates of median duration, extinction rate, and completeness are not biased.(3) The shorter geologic ranges of mammalian species relative to those of bivalves cannot be attributed to a difference in preservation potential. However, we cannot rule out the contribution of taxonomic practice to this difference. (4) In the groups studied, completeness (proportion of species [trilobites, bivalves, mammals] or genera [crinoids] preserved) ranges from 60% to 90%. The higher estimates of completeness at smaller geographic scales support previous suggestions that the incompleteness of the fossil record reflects loss of

The first record of a trans-oceanic sister-group relationship between obligate vertebrate troglobites.

Directory of Open Access Journals (Sweden)

Prosanta Chakrabarty

Full Text Available We show using the most complete phylogeny of one of the most species-rich orders of vertebrates (Gobiiformes, and calibrations from the rich fossil record of teleost fishes, that the genus Typhleotris, endemic to subterranean karst habitats in southwestern Madagascar, is the sister group to Milyeringa, endemic to similar subterranean systems in northwestern Australia. Both groups are eyeless, and our phylogenetic and biogeographic results show that these obligate cave fishes now found on opposite ends of the Indian Ocean (separated by nearly 7,000 km are each others closest relatives and owe their origins to the break up of the southern supercontinent, Gondwana, at the end of the Cretaceous period. Trans-oceanic sister-group relationships are otherwise unknown between blind, cave-adapted vertebrates and our results provide an extraordinary case of Gondwanan vicariance.

Miocene Fossils Reveal Ancient Roots for New Zealand's Endemic Mystacina (Chiroptera and Its Rainforest Habitat.

Directory of Open Access Journals (Sweden)

Suzanne J Hand

Full Text Available The New Zealand endemic bat family Mystacinidae comprises just two Recent species referred to a single genus, Mystacina. The family was once more diverse and widespread, with an additional six extinct taxa recorded from Australia and New Zealand. Here, a new mystacinid is described from the early Miocene (19-16 Ma St Bathans Fauna of Central Otago, South Island, New Zealand. It is the first pre-Pleistocene record of the modern genus and it extends the evolutionary history of Mystacina back at least 16 million years. Extant Mystacina species occupy old-growth rainforest and are semi-terrestrial with an exceptionally broad omnivorous diet. The majority of the plants inhabited, pollinated, dispersed or eaten by modern Mystacina were well-established in southern New Zealand in the early Miocene, based on the fossil record from sites at or near where the bat fossils are found. Similarly, many of the arthropod prey of living Mystacina are recorded as fossils in the same area. Although none of the Miocene plant and arthropod species is extant, most are closely related to modern taxa, demonstrating potentially long-standing ecological associations with Mystacina.

Mummified fossil woods of Fagaceae from the upper Oligocene of Guangxi, South China

Science.gov (United States)

Huang, Luliang; Jin, Jianhua; Quan, Cheng; Oskolski, Alexei A.

2018-02-01

Three new fossil species, two attributed to the genus Castanopsis (C. nanningensis and C. guangxiensis) and one to the organ genus Lithocarpoxylon (L. nanningensis) are described on the basis of well-preserved mummified wood from the upper Oligocene of Yongning Formation in the Nanning Basin, Guangxi Province, South China. The two species of Castanopsis represent the most ancient reliable wood record of this genus in China and also southeastern Asia, which is the center of diversity of extant species. The fossil leaf records of Castanopsis indicated this genus has migrated to South China in the late Eocene. This fossil wood evidence confirms the presence and persistence of Castanopsis in this region in the late Oligocene. In the Yongning Formation, the presence of numerous Fagaceae woods with faint or absent growth ring boundaries (in C. nanningensis) occasionally associated with prominent ring-porous patterns, suggests that Guangxi (South China) had a seasonal (probably monsoonal) tropical climate during the late Oligocene.

The fossil Osmundales (Royal Ferns)—a phylogenetic network analysis, revised taxonomy, and evolutionary classification of anatomically preserved trunks and rhizomes

OpenAIRE

Benjamin Bomfleur; Guido W. Grimm; Stephen McLoughlin

2017-01-01

The Osmundales (Royal Fern order) originated in the late Paleozoic and is the most ancient surviving lineage of leptosporangiate ferns. In contrast to its low diversity today (less than 20 species in six genera), it has the richest fossil record of any extant group of ferns. The structurally preserved trunks and rhizomes alone are referable to more than 100 fossil species that are classified in up to 20 genera, four subfamilies, and two families. This diverse fossil record constitutes an exce...

Cryptic iridescence in a fossil weevil generated by single diamond photonic crystals.

Science.gov (United States)

McNamara, Maria E; Saranathan, Vinod; Locatelli, Emma R; Noh, Heeso; Briggs, Derek E G; Orr, Patrick J; Cao, Hui

2014-11-06

Nature's most spectacular colours originate in integumentary tissue architectures that scatter light via nanoscale modulations of the refractive index. The most intricate biophotonic nanostructures are three-dimensional crystals with opal, single diamond or single gyroid lattices. Despite intense interest in their optical and structural properties, the evolution of such nanostructures is poorly understood, due in part to a lack of data from the fossil record. Here, we report preservation of single diamond (Fd-3m) three-dimensional photonic crystals in scales of a 735,000 year old specimen of the brown Nearctic weevil Hypera diversipunctata from Gold Run, Canada, and in extant conspecifics. The preserved red to green structural colours exhibit near-field brilliancy yet are inconspicuous from afar; they most likely had cryptic functions in substrate matching. The discovery of pristine fossil examples indicates that the fossil record is likely to yield further data on the evolution of three-dimensional photonic nanostructures and their biological functions. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

An evaluation of fossil tip-dating versus node-age calibrations in tetraodontiform fishes (Teleostei: Percomorphaceae).

Science.gov (United States)

Arcila, Dahiana; Alexander Pyron, R; Tyler, James C; Ortí, Guillermo; Betancur-R, Ricardo

2015-01-01

Time-calibrated phylogenies based on molecular data provide a framework for comparative studies. Calibration methods to combine fossil information with molecular phylogenies are, however, under active development, often generating disagreement about the best way to incorporate paleontological data into these analyses. This study provides an empirical comparison of the most widely used approach based on node-dating priors for relaxed clocks implemented in the programs BEAST and MrBayes, with two recently proposed improvements: one using a new fossilized birth-death process model for node dating (implemented in the program DPPDiv), and the other using a total-evidence or tip-dating method (implemented in MrBayes and BEAST). These methods are applied herein to tetraodontiform fishes, a diverse group of living and extinct taxa that features one of the most extensive fossil records among teleosts. Previous estimates of time-calibrated phylogenies of tetraodontiforms using node-dating methods reported disparate estimates for their age of origin, ranging from the late Jurassic to the early Paleocene (ca. 150-59Ma). We analyzed a comprehensive dataset with 16 loci and 210 morphological characters, including 131 taxa (95 extant and 36 fossil species) representing all families of fossil and extant tetraodontiforms, under different molecular clock calibration approaches. Results from node-dating methods produced consistently younger ages than the tip-dating approaches. The older ages inferred by tip dating imply an unlikely early-late Jurassic (ca. 185-119Ma) origin for this order and the existence of extended ghost lineages in their fossil record. Node-based methods, by contrast, produce time estimates that are more consistent with the stratigraphic record, suggesting a late Cretaceous (ca. 86-96Ma) origin. We show that the precision of clade age estimates using tip dating increases with the number of fossils analyzed and with the proximity of fossil taxa to the node under

FOSSIL2 energy policy model documentation: FOSSIL2 documentation

Energy Technology Data Exchange (ETDEWEB)

None

1980-10-01

This report discusses the structure, derivations, assumptions, and mathematical formulation of the FOSSIL2 model. Each major facet of the model - supply/demand interactions, industry financing, and production - has been designed to parallel closely the actual cause/effect relationships determining the behavior of the United States energy system. The data base for the FOSSIL2 program is large, as is appropriate for a system dynamics simulation model. When possible, all data were obtained from sources well known to experts in the energy field. Cost and resource estimates are based on DOE data whenever possible. This report presents the FOSSIL2 model at several levels. Volumes II and III of this report list the equations that comprise the FOSSIL2 model, along with variable definitions and a cross-reference list of the model variables. Volume II provides the model equations with each of their variables defined, while Volume III lists the equations, and a one line definition for equations, in a shorter, more readable format.

Taxonomic revision of the fossil pulmonate mollusks of Itaboraí Basin (Paleocene, Brazil

Directory of Open Access Journals (Sweden)

Rodrigo Brincalepe Salvador

2013-01-01

Full Text Available The limestones of Itaboraí Basin (Middle Paleocene, Rio de Janeiro, Brazil, harbor a rich fossil molluscan fauna consisting exclusively of pulmonate snails, both terrestrial and freshwater. An extensive taxonomic revision of this paleofauna is conducted here. A new genus, Cortana, is described as well as two new species, Eoborus fusiforme and Gastrocopta itaboraiensis. The revised classification is as follows: Austrodiscus lopesi (Charopidae; Biomphalaria itaboraiensis (Planorbidae; "Brachypodella" britoi (Urocoptidae; Brasilennea arethusae, Brasilennea guttula, Brasilennea minor (Cerionidae; Bulimulus fazendicus, Bulimulus trindadeae, Cortana carvalhoi, Cyclodontina coelhoi, Itaborahia lamegoi, Leiostracus ferreirai, Plagiodontes aff. dentatus (Orthalicidae; Cecilioides sommeri (Ferussaciidae; Eoborus rotundus, Eoborus sanctijosephi, Eoborus fusiforme (Strophocheilidae; Gastrocopta mezzalirai, Gastrocopta itaboraiensis (Gastrocoptidae; Temesa magalhaesi (Clausiliidae. The species Strobilopsis mauryae was considered a synonym of Brasilennea arethusae; Bulimulus sommeri a synonym of Itaborahia lamegoi; and Vorticifex fluminensis a synonym of Eoborus sanctijosephi. Itaboraí Basin has the most ancient records of the families Orthalicidae, Gastrocoptidae, Ferussaciidae and Strophocheilidae. Moreover, the basin's records of Charopidae, Clausiliidae, Cerionidae, and Urocoptidae are among the most ancient in the world and, among these, those of Cerionidae, Clausiliidae and Urocoptidae deserve special attention since they are greatly removed from these families' current distribution. Additionally, Itaboraí has the most ancient records for the genera Austrodiscus, Brachypodella, Bulimulus, Cecilioides, Cyclodontina, Eoborus, Gastrocopta, Leiostracus, Plagiodontes and Temesa. There are three endemic genera in the basin: Brasilennea, Cortana and Itaborahia. Further discussion on paleobiogeography and evolution of this paleofauna is also provided.

Automation of Presentation Record Production Based on Rich-Media Technology Using SNT Petri Nets Theory

Directory of Open Access Journals (Sweden)

Ivo Martiník

2015-01-01

Full Text Available Rich-media describes a broad range of digital interactive media that is increasingly used in the Internet and also in the support of education. Last year, a special pilot audiovisual lecture room was built as a part of the MERLINGO (MEdia-rich Repository of LearnING Objects project solution. It contains all the elements of the modern lecture room determined for the implementation of presentation recordings based on the rich-media technologies and their publication online or on-demand featuring the access of all its elements in the automated mode including automatic editing. Property-preserving Petri net process algebras (PPPA were designed for the specification and verification of the Petri net processes. PPPA does not need to verify the composition of the Petri net processes because all their algebraic operators preserve the specified set of the properties. These original PPPA are significantly generalized for the newly introduced class of the SNT Petri process and agent nets in this paper. The PLACE-SUBST and ASYNC-PROC algebraic operators are defined for this class of Petri nets and their chosen properties are proved. The SNT Petri process and agent nets theory were significantly applied at the design, verification, and implementation of the programming system ensuring the pilot audiovisual lecture room functionality.

The Late Pleistocene-Holocene community development in Central and SE-Europe in direct fossil record: scope of the approach, common patterns and inter-regional differences.

Science.gov (United States)

Horacek, Ivan; Lozek, Vojen

2010-05-01

The information provided by modern instrumental approaches (molecular phylogeography, ancient DNA analyses, large scale radiocarbon datings etc.) refined the knowledge on Late Quaternary faunal development and range history of particular taxa in essential way. Nevertheless, the direct fossil record remains still an essential substrate in study of that topics, and to reveal all the information, that it may provide, and integrate it with the outputs of the other approaches presents one of the essential aim of the present meeting. Unfortunately, the immediate use of fossil record for the paleoecologic and paleobiogeographic inferences is often limited by its fragmentarity (both in temporal and spatial respects), taphonomic influences and/or locally specific post-sedimentary effects which all may bias it in a considerable degree. Hence, each particular record is to be carefully reexamined in respect to all factor which may bias it - unfortunately, often it is not too easy to respond that task, particularly when the record is retrived from secondary sources. It should also be remembered that the records representing narrow time slices without a robust lithostratigraphic context do not provide any information on the historical and contextual setting of the respective faunal situation. Such information that is essential for reconstructions of paleobiogeography of community development and similar locally-sensitive phenomena can only be retrived from the continuous sedimentary series which establish the sequence of particular faunal events by direct superposition. A sufficiently dense network of such series provides than a possibility of direct inter-regional comparisons and a high resolution information on the paleobiogeography of the Late Pleistocene-Holocene rearrangements of mammalian communities, local variation in history of particular species and its community context. We illustrate productivity of such approach on with aid of the fossil record obtained from

Fossil Fuels.

Science.gov (United States)

Crank, Ron

This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with fossil fuels. Some topics covered are historic facts, development of fuels, history of oil production, current and future trends of the oil industry, refining fossil fuels, and environmental problems. Material in each unit may…

Total-Evidence Dating under the Fossilized Birth-Death Process.

Science.gov (United States)

Zhang, Chi; Stadler, Tanja; Klopfstein, Seraina; Heath, Tracy A; Ronquist, Fredrik

2016-03-01

Bayesian total-evidence dating involves the simultaneous analysis of morphological data from the fossil record and morphological and sequence data from recent organisms, and it accommodates the uncertainty in the placement of fossils while dating the phylogenetic tree. Due to the flexibility of the Bayesian approach, total-evidence dating can also incorporate additional sources of information. Here, we take advantage of this and expand the analysis to include information about fossilization and sampling processes. Our work is based on the recently described fossilized birth-death (FBD) process, which has been used to model speciation, extinction, and fossilization rates that can vary over time in a piecewise manner. So far, sampling of extant and fossil taxa has been assumed to be either complete or uniformly at random, an assumption which is only valid for a minority of data sets. We therefore extend the FBD process to accommodate diversified sampling of extant taxa, which is standard practice in studies of higher-level taxa. We verify the implementation using simulations and apply it to the early radiation of Hymenoptera (wasps, ants, and bees). Previous total-evidence dating analyses of this data set were based on a simple uniform tree prior and dated the initial radiation of extant Hymenoptera to the late Carboniferous (309 Ma). The analyses using the FBD prior under diversified sampling, however, date the radiation to the Triassic and Permian (252 Ma), slightly older than the age of the oldest hymenopteran fossils. By exploring a variety of FBD model assumptions, we show that it is mainly the accommodation of diversified sampling that causes the push toward more recent divergence times. Accounting for diversified sampling thus has the potential to close the long-discussed gap between rocks and clocks. We conclude that the explicit modeling of fossilization and sampling processes can improve divergence time estimates, but only if all important model aspects

New findings of Pleistocene fossil turtles (Geoemydidae, Kinosternidae and Chelydridae from Santa Elena Province, Ecuador

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Edwin A. Cadena

2017-04-01

Full Text Available New Pleistocene fossilized turtle remains from five localities of western Ecuador (Santa Elena Province are described here. All these shell (carapace and plastron fossil remains come from the Tablazo Formation and belong to three different lineages of cryptodires (“hidden-necked” turtles. The most abundant remains belong to geoemydids, attributed here to the genus Rhinoclemmys (indeterminate species. Less abundant in occurrence are the kinosternidids, attributed to Kinosternon (indeterminate species, and the first fossil record of chelydrids, Chelydra(indeterminate species, in the entirety of Central and South America.

RX J1548.9+0851, a fossil cluster?

Science.gov (United States)

Eigenthaler, P.; Zeilinger, W. W.

2012-04-01

Vaucouleurs r1/4 law without a cD envelope. Symmetric shells are revealed along the major axis of the galaxy indicating a recent minor merger. RX J1548.9+0851 shows a steep, increasing luminosity function with a faint-end slope of α = -1.4 ± 0.1. Satellite galaxies show a clear spatial segregation with respect to their stellar populations - objects with old stars are confined to an elongated, central distribution aligned with the major axis of the central elliptical. Conclusions: Although RX J1548.9+0851 shows similar properties compared to other fossils studied recently, it might not be a fossil at all, being dominated by 2 bright central ellipticals. Comparing RX J1548.9+0851 with scaling relations from ordinary poor groups and clusters confirm the idea that fossils might simply be normal clusters with the richness and optical luminosity of poor groups.

REVISITING THE FOSSIL GROUP CANDIDATES UGC 842 AND NGC 6034

International Nuclear Information System (INIS)

De Oliveira, R. Lopes; De Oliveira, C. Mendes; Bortoletto, D. R.; Cypriano, E.; Sodre, L.; Neto, G B. Lima; Carrasco, E. R.

2010-01-01

We present a new insight on NGC 6034 and UGC 842, two groups of galaxies previously reported in the literature as being fossil groups. The study is based on optical photometry and spectroscopy obtained with the CTIO Blanco telescope and Sloan Digital Sky Survey archival data. We find that NGC 6034 is embedded in a large structure, dominated by three rich clusters and other small groups. Its first and next four ranked galaxies have magnitude differences in the r band and projected distances which violate the optical criteria to classify it as a fossil group. We confirm that the UGC 842 group is a fossil group, but with about half the velocity dispersion that is reported in previous works. The velocity distribution of its galaxies reveals the existence of two structures in its line of sight, one with σ v ∼ 223 km s -1 and another with σ v ∼ 235 km s -1 , with a difference in velocity of ∼820 km s -1 . The main structure is dominated by passive galaxies, while these represent ∼60% of the second structure. The X-ray temperature for the intragroup medium of a group with such a velocity dispersion is expected to be kT ∼0.5-1 keV, against the observed value of kT ∼1.9 keV reported in the literature. This result makes UGC 842 a special case among fossil groups because (1) it represents more likely the interaction between two small groups, which warms the intragroup medium and/or (2) it could constitute evidence that member galaxies lost energy in the process of spiraling toward the group center, and decreased the velocity dispersion of the system. As far as we know, UGC 842 is the first low-mass fossil group studied in detail.

Checklist of fossil decapod crustaceans from tropical America. Part I: Anomura and Brachyura

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Javier Luque

2017-10-01

Full Text Available Abstract Our knowledge of fossil crustaceans from the tropics has increased considerably during recent decades, thanks to novel findings and the re-examination of museum specimens. However, several previous records have been misidentified, numerous museum specimens have never been reported, and many new discoveries are yet to be published. Here, we present a detailed, up-to-date, and revised checklist for every marine, terrestrial, or freshwater fossil decapod crustacean occurrence from tropical America known to us, including their age, geographic occurrences, and related literature. We recognize the occurrence of at least 32 superfamilies, 69 families, 190 genera, and 415 species of brachyurans (‘true’ crabs, and anomurans (‘false’ crabs, hermit crabs, squat lobsters, and allies, several of them previously unknown. The checklist comprises records from three main geographic regions: 1 northern South America (Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela; 2 Central America and southern North America (Belize, Costa Rica, Honduras, Panama, Mexico, southern and central Florida; and 3 the Caribbean Islands + Bermuda (Anguilla, Antigua, Aruba, Bahamas, Barbados, Bermuda, Bonaire, Cuba, Curaçao, Dominican Republic, The Grenadines, Haiti, Jamaica, Puerto Rico, Saint Bartélemy, Saint Martin, Trinidad. Previous findings, new occurrences, and the revised systematic placement for several problematic/misidentified records, indicate that the fossil record of anomurans and brachyurans in tropical America is more diverse than previously envisioned, with a considerable degree of endemism at the genus- and species-levels.

Challenges in estimating past plant diversity from fossil pollen data: statistical assessment, problems, and possible solutions.

NARCIS (Netherlands)

Weng, C.; Hooghiemstra, H.; Duivenvoorden, J.F.

2006-01-01

Fossil pollen data from sediment cores may be used as a measure for past plant diversity. According to the theory of probability, palynological richness is positively related to the pollen count. In a low pollen count, only common taxa are detected, whereas rare taxa are only detected by chance. The

FIRST RECORD OF FOSSIL CYSTOPHORINAE (CARNIVORA, PHOCIDAE: MIDDLE MIOCENE SEALS FROM THE NORTHERN PARATETHYS

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IRINA A. KORETSKY

2013-11-01

Full Text Available Despite a long history of phocid studies, no fossil members of the Subfamily Cystophorinae have ever been described. New fossil material from the Middle Sarmatian (11.2-12.3 Ma in the Paratethyan Basin of Ukraine allows emended diagnoses and redescriptions to help clarify phylogenetic relationships within the Family Phocidae. After cladistic and morphological analyses of the material, a new genus ( Pachyphoca  was erected, with two new species of extinct fossil true seals ( Pachyphoca ukrainica and Pachyphoca chapskii , belonging to the Subfamily Cystophorinae. This new material shows exceptional pachyosteosclerotic bones, which is uncommon for the family as a whole. The new Miocene genus shares numerous characters with several Recent species of Cystophora and Mirounga , providing the first opportunity to study sexual dimorphism of limb bones and mandibles in the Subfamily Cystophorinae. Sexual dimorphism in postcranial bones and mandibles in living members of Cystophorinae is more obvious than in other representatives of true seals. Examination of anatomical traits demonstrated that both new species are more primitive and better adapted for terrestrial locomotion than any living representatives of Cystophorinae. The smaller Pachyphoca ukrainica is more adapted to terrestrial locomotion than its larger relative, P . chapskii . Phylogenetic analysis suggests that seals with 10 incisors (Phocinae are more primitive than those with 8 (Monachinae, and that Monachinae are more primitive than seals with 6 incisors (Cystophorinae.These findings indicate that the Subfamily Cystophorinae includes not only elephant and hooded seals, but also the two new Middle Sarmatian pachyosteosclerotic seals. 

Avian fossils from the Early Miocene Moghra Formation of Egypt ...

African Journals Online (AJOL)

Avian remains from the Early Miocene (~17 Ma) Moghra Formation of Egypt include new records of 'waterbirds' (storks, herons, pelicans and allies) and a ratite. Only a single avian fossil has been previously reported from Wadi Moghra and, thus, additional knowledge of the avifauna complements previously documented ...

A fossil brain from the Cretaceous of European Russia and avian sensory evolution.

Science.gov (United States)

Kurochkin, Evgeny N; Dyke, Gareth J; Saveliev, Sergei V; Pervushov, Evgeny M; Popov, Evgeny V

2007-06-22

Fossils preserving traces of soft anatomy are rare in the fossil record; even rarer is evidence bearing on the size and shape of sense organs that provide us with insights into mode of life. Here, we describe unique fossil preservation of an avian brain from the Volgograd region of European Russia. The brain of this Melovatka bird is similar in shape and morphology to those of known fossil ornithurines (the lineage that includes living birds), such as the marine diving birds Hesperornis and Enaliornis, but documents a new stage in avian sensory evolution: acute nocturnal vision coupled with well-developed hearing and smell, developed by the Late Cretaceous (ca 90Myr ago). This fossil also provides insights into previous 'bird-like' brain reconstructions for the most basal avian Archaeopteryx--reduction of olfactory lobes (sense of smell) and enlargement of the hindbrain (cerebellum) occurred subsequent to Archaeopteryx in avian evolution, closer to the ornithurine lineage that comprises living birds. The Melovatka bird also suggests that brain enlargement in early avians was not correlated with the evolution of powered flight.

Borassodendron (Palmae) in the Southeast Asian fossil pollen record

NARCIS (Netherlands)

Maloney, B.K.

2000-01-01

Borassodendron machadonis pollen occurred throughout the Holocene pollen record of Nong Thale Song Hong, Thailand, until about 4000 BP. It was also present in one sample from Khok Phanom Di, Thailand, and in the Mahakam Delta, Kalimantan, records, but B. machadonis has not been reported from the

A fossil unicorn crestfish (Teleostei, Lampridiformes, Lophotidae) from the Eocene of Iran.

Science.gov (United States)

Davesne, Donald

2017-01-01

Lophotidae, or crestfishes, is a family of rare deep-sea teleosts characterised by an enlarged horn-like crest on the forehead. They are poorly represented in the fossil record, by only three described taxa. One specimen attributed to Lophotidae has been described from the pelagic fauna of the middle-late Eocene Zagros Basin, Iran. Originally considered as a specimen of the fossil lophotid † Protolophotus , it is proposed hereby as a new genus and species † Babelichthys olneyi , gen. et sp. nov., differs from the other fossil lophotids by its relatively long and strongly projecting crest, suggesting a close relationship with the modern unicorn crestfish, Eumecichthys . This new taxon increases the diversity of the deep-sea teleost fauna to which it belongs, improving our understanding of the taxonomic composition of the early Cenozoic mesopelagic ecosystems.

The fossilized birth–death process for coherent calibration of divergence-time estimates

Science.gov (United States)

Heath, Tracy A.; Huelsenbeck, John P.; Stadler, Tanja

2014-01-01

Time-calibrated species phylogenies are critical for addressing a wide range of questions in evolutionary biology, such as those that elucidate historical biogeography or uncover patterns of coevolution and diversification. Because molecular sequence data are not informative on absolute time, external data—most commonly, fossil age estimates—are required to calibrate estimates of species divergence dates. For Bayesian divergence time methods, the common practice for calibration using fossil information involves placing arbitrarily chosen parametric distributions on internal nodes, often disregarding most of the information in the fossil record. We introduce the “fossilized birth–death” (FBD) process—a model for calibrating divergence time estimates in a Bayesian framework, explicitly acknowledging that extant species and fossils are part of the same macroevolutionary process. Under this model, absolute node age estimates are calibrated by a single diversification model and arbitrary calibration densities are not necessary. Moreover, the FBD model allows for inclusion of all available fossils. We performed analyses of simulated data and show that node age estimation under the FBD model results in robust and accurate estimates of species divergence times with realistic measures of statistical uncertainty, overcoming major limitations of standard divergence time estimation methods. We used this model to estimate the speciation times for a dataset composed of all living bears, indicating that the genus Ursus diversified in the Late Miocene to Middle Pliocene. PMID:25009181

A high-elevation, multi-proxy biotic and environmental record of MIS 6-4 from the Ziegler Reservoir fossil site, Snowmass Village, Colorado, USA

Science.gov (United States)

Miller, Ian M.; Pigati, Jeffrey S.; Anderson, R. Scott; Johnson, Kirk R.; Mahan, Shannon; Ager, Thomas A.; Baker, Richard G.; Blaauw, Maarten; Bright, Jordon; Brown, Peter M.; Bryant, Bruce; Calamari, Zachary T.; Carrara, Paul E.; Michael D., Cherney; Demboski, John R.; Elias, Scott A.; Fisher, Daniel C.; Gray, Harrison J.; Haskett, Danielle R.; Honke, Jeffrey S.; Jackson, Stephen T.; Jiménez-Moreno, Gonzalo; Kline, Douglas; Leonard, Eric M.; Lifton, Nathaniel A.; Lucking, Carol; McDonald, H. Gregory; Miller, Dane M.; Muhs, Daniel R.; Nash, Stephen E.; Newton, Cody; Paces, James B.; Petrie, Lesley; Plummer, Mitchell A.; Porinchu, David F.; Rountrey, Adam N.; Scott, Eric; Sertich, Joseph J. W.; Sharpe, Saxon E.; Skipp, Gary L.; Strickland, Laura E.; Stucky, Richard K.; Thompson, Robert S.; Wilson, Jim

2014-01-01

In North America, terrestrial records of biodiversity and climate change that span Marine Oxygen Isotope Stage (MIS) 5 are rare. Where found, they provide insight into how the coupling of the ocean–atmosphere system is manifested in biotic and environmental records and how the biosphere responds to climate change. In 2010–2011, construction at Ziegler Reservoir near Snowmass Village, Colorado (USA) revealed a nearly continuous, lacustrine/wetland sedimentary sequence that preserved evidence of past plant communities between ~ 140 and 55 ka, including all of MIS 5. At an elevation of 2705 m, the Ziegler Reservoir fossil site also contained thousands of well-preserved bones of late Pleistocene megafauna, including mastodons, mammoths, ground sloths, horses, camels, deer, bison, black bear, coyotes, and bighorn sheep. In addition, the site contained more than 26,000 bones from at least 30 species of small animals including salamanders, otters, muskrats, minks, rabbits, beavers, frogs, lizards, snakes, fish, and birds. The combination of macro- and micro-vertebrates, invertebrates, terrestrial and aquatic plant macrofossils, a detailed pollen record, and a robust, directly dated stratigraphic framework shows that high-elevation ecosystems in the Rocky Mountains of Colorado are climatically sensitive and varied dramatically throughout MIS 5.

The First Galaxies and the Likely Discovery of Their Fossils in the Local Group

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Massimo Ricotti

2010-01-01

Full Text Available The lower bound for the mass of a galaxy is unknown, as are the typical luminosity of the smallest galaxies and their numbers. The answers depend on the extent to which star formation in the first population of small mass halos may be suppressed by radiative feedback loops. If early populations of dwarf galaxies did form in significant number before reionization, their “fossils” should be found today in the Local Group. This paper reviews our ongoing efforts to simulate and identify fossil dwarfs in the Local Group. It is widely believed that reionization stopped star formation in fossil dwarfs. However, here we dispute this idea and discuss a physical mechanism whereby recent episodes of star formation would be produced in some fossil dwarfs that, hence, may characterized by a bimodal star formation history. The same mechanism could turn dark halos that failed to form stars before reionization into gas-rich “dark galaxies”. We believe that current observational data supports the thesis that a fraction of the new ultra-faint dwarfs discovered in the Local Group are fossil dwarfs and we predict the existence of a population of ultra-faint dwarfs with lower surface brightness than currently observed.

New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens

OpenAIRE

Hublin, Jean-Jacques; Ben-Ncer, Abdelouahed; Bailey, Shara E.; Freidline, Sarah E.; Neubauer, Simon; Skinner, Matthew M.; Bergmann, Inga; Le Cabec, Adeline; Benazzi, Stefano; Harvati, Katerina; Gunz, Philipp

2017-01-01

Fossil evidence points to an African origin of Homo sapiens from a group called either H. heidelbergensis or H. rhodesiensis. However, the exact place and time of emergence of H. sapiens remain obscure because the fossil record is scarce and the chronological age of many key specimens remains uncertain. In particular, it is unclear whether the present day ‘modern’ morphology rapidly emerged approximately 200 thousand years ago (ka) among earlier representatives of H. sapiens1 or evolved gradu...

[The fossil record of the Eurasian Neogene insectivores (Erinaceomorpha, Soricomorpha, Mammalia) : Part I / L.W. van den Hoek Ostende, C.S. Doukas and J.W.F. Reumer (editors)]: Czech Republic and Slovak Republic

NARCIS (Netherlands)

Fejfar, O.; Sabol, M.

2005-01-01

Introduction The fossil record of insectivores in Czech Republic comes from two different settings: A. in the stratified deposits in the North Bohemian tectonic rift (the sites; Tuchořice, the Open Mine Merkur-Nord near Chomutov, Dolnice and Františkovy Lázně (Franzensbad), and Β. in the karstic

Biomineralization and biosignatures of coralloid-type speleothems from lava tubes of Galapagos Islands: evidences on the fossil record of prokaryotes

Science.gov (United States)

Miller, Ana Z.; Garcia-Sanchez, Angela M.; Pereira, Manuel F. C.; Gazquez, Fernando; Calaforra, José M.; Forti, Paolo; Toulkeridis, Theofilos; Martínez-Frías, Jesús; Saiz-Jimenez, Cesareo

2016-04-01

, whereas the final stage mainly consists of low crystalline calcite. FESEM-EDS analysis revealed mineralized bacterial filaments rich in Si on the coralloid samples, as well as minerals precipitation associated with extracellular polymeric substances (EPS), which serve as nuclei for preferential precipitation on the extracellular sheaths. This suggests that biological activity played a major role in the development of these speleothems. In addition, imprints of filamentous cells and microboring readily preserved on siliceous minerals were observed on the coralloid speleothems. These features are recognized as biosignatures valuable for astrobiology and may represent modern analogs of the fossil record of prokaryotes. DNA-based analyses showed that bacteria belonging to Actinobacteria (31%) Gemmatimonadetes (25%) and Proteobacteria (24%) phyla dominated in this cave ecosystem, followed by Acidobacteria, Firmicutes and Nitrospirae. Most of the identified phylotypes were affiliated to chemoautotrophs, including thermophilic bacteria such as Ferrithrix thermotolerans, and other mineral utilizing microorganisms like Aciditerrimonas ferrireducens, Desulfuromonas sp. and Desulfovibrio sp., indicating that Galapagos lava tubes host highly specialized subsurface biosphere dominated by microorganisms able to interact with minerals and promote biomineralization. Acknowledgments: This work has been supported by the project PC-65-14 from the Ministry of Environment of Ecuador. AZM acknowledges the support from the Marie Curie Fellowship of the 7th EC Framework Programme (PIEF-GA-2012-328689-DECAVE). The authors acknowledge the Spanish Ministry of Economy and Competitiveness (project CGL2013-41674-P) and FEDER funds for financial support.

FINDING FOSSIL GROUPS: OPTICAL IDENTIFICATION AND X-RAY CONFIRMATION

Energy Technology Data Exchange (ETDEWEB)

Miller, Eric D. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 (United States); Rykoff, Eli S. [E.O. Lawrence Berkeley National Lab, 1 Cyclotron Rd., Berkeley, CA 94720 (United States); Dupke, Renato A. [Department of Astronomy, University of Michigan, 500 Church St., Ann Arbor, MI 48109 (United States); Mendes de Oliveira, Claudia; Proctor, Robert N. [Departamento de Astronomia, Instituto de Astronomia, Geofisica e Ciencias Atmosfericas da Universidade de Sao Paulo, Rua do Matao 1226, Cidade Universitaria, 05508-090 Sao Paulo (Brazil); Lopes de Oliveira, Raimundo [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Caixa Postal 369, 13560-970 Sao Carlos, SP (Brazil); Garmire, Gordon P. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Koester, Benjamin P. [Department of Astronomy and Astrophysics, The University of Chicago, Chicago, IL 60637 (United States); McKay, Timothy A., E-mail: milleric@mit.edu [Department of Physics, University of Michigan, 450 Church St., Ann Arbor, MI 48109 (United States)

2012-03-10

We report the discovery of 12 new fossil groups (FGs) of galaxies, systems dominated by a single giant elliptical galaxy and cluster-scale gravitational potential, but lacking the population of bright galaxies typically seen in galaxy clusters. These FGs, selected from the maxBCG optical cluster catalog, were detected in snapshot observations with the Chandra X-ray Observatory. We detail the highly successful selection method, with an 80% success rate in identifying 12 FGs from our target sample of 15 candidates. For 11 of the systems, we determine the X-ray luminosity, temperature, and hydrostatic mass, which do not deviate significantly from expectations for normal systems, spanning a range typical of rich groups and poor clusters of galaxies. A small number of detected FGs are morphologically irregular, possibly due to past mergers, interaction of the intra-group medium with a central active galactic nucleus (AGN), or superposition of multiple massive halos. Two-thirds of the X-ray-detected FGs exhibit X-ray emission associated with the central brightest cluster galaxy (BCG), although we are unable to distinguish between AGN and extended thermal galaxy emission using the current data. This sample representing a large increase in the number of known FGs, will be invaluable for future planned observations to determine FG temperature, gas density, metal abundance, and mass distributions, and to compare to normal (non-fossil) systems. Finally, the presence of a population of galaxy-poor systems may bias mass function determinations that measure richness from galaxy counts. When used to constrain power spectrum normalization and {Omega}{sub m}, these biased mass functions may in turn bias these results.

A fossil unicorn crestfish (Teleostei, Lampridiformes, Lophotidae from the Eocene of Iran

Directory of Open Access Journals (Sweden)

Donald Davesne

2017-06-01

Full Text Available Lophotidae, or crestfishes, is a family of rare deep-sea teleosts characterised by an enlarged horn-like crest on the forehead. They are poorly represented in the fossil record, by only three described taxa. One specimen attributed to Lophotidae has been described from the pelagic fauna of the middle-late Eocene Zagros Basin, Iran. Originally considered as a specimen of the fossil lophotid †Protolophotus, it is proposed hereby as a new genus and species †Babelichthys olneyi, gen. et sp. nov., differs from the other fossil lophotids by its relatively long and strongly projecting crest, suggesting a close relationship with the modern unicorn crestfish, Eumecichthys. This new taxon increases the diversity of the deep-sea teleost fauna to which it belongs, improving our understanding of the taxonomic composition of the early Cenozoic mesopelagic ecosystems.

Status of fossil fuel reserves; Etat des reserves des combustibles fossiles

Energy Technology Data Exchange (ETDEWEB)

Laherrere, J

2005-07-01

Reserves represent the sum of past and future productions up to the end of production. In most countries the reserve data of fields are confidential. Therefore, fossil fuel reserves are badly known because the published data are more political than technical and many countries make a confusion between resources and reserves. The cumulated production of fossil fuels represents only between a third and a fifth of the ultimate reserves. The production peak will take place between 2020 and 2050. In the ultimate reserves, which extrapolate the past, the fossil fuels represent three thirds of the overall energy. This document analyses the uncertainties linked with fossil fuel reserves: reliability of published data, modeling of future production, comparison with other energy sources, energy consumption forecasts, reserves/production ratio, exploitation of non-conventional hydrocarbons (tar sands, extra-heavy oils, bituminous shales, coal gas, gas shales, methane in overpressure aquifers, methane hydrates), technology impacts, prices impact, and reserves growth. (J.S.)

Biofuel: an alternative to fossil fuel for alleviating world energy and economic crises.

Science.gov (United States)

Bhattarai, Keshav; Stalick, Wayne M; McKay, Scott; Geme, Gija; Bhattarai, Nimisha

2011-01-01

The time has come when it is desirable to look for alternative energy resources to confront the global energy crisis. Consideration of the increasing environmental problems and the possible crisis of fossil fuel availability at record high prices dictate that some changes will need to occur sooner rather than later. The recent oil spill in the Gulf of Mexico is just another example of the environmental threats that fossil fuels pose. This paper is an attempt to explore various bio-resources such as corn, barley, oat, rice, wheat, sorghum, sugar, safflower, and coniferous and non-coniferous species for the production of biofuels (ethanol and biodiesel). In order to assess the potential production of biofuel, in this paper, countries are organized into three groups based on: (a) geographic areas; (b) economic development; and(c) lending types, as classified by the World Bank. First, the total fossil fuel energy consumption and supply and possible carbon emission from burning fossil fuel is projected for these three groups of countries. Second, the possibility of production of biofuel from grains and vegetative product is projected. Third, a comparison of fossil fuel and biofuel is done to examine energy sustainability issues.

Upward revision of global fossil fuel methane emissions based on isotope database.

Science.gov (United States)

Schwietzke, Stefan; Sherwood, Owen A; Bruhwiler, Lori M P; Miller, John B; Etiope, Giuseppe; Dlugokencky, Edward J; Michel, Sylvia Englund; Arling, Victoria A; Vaughn, Bruce H; White, James W C; Tans, Pieter P

2016-10-06

Methane has the second-largest global radiative forcing impact of anthropogenic greenhouse gases after carbon dioxide, but our understanding of the global atmospheric methane budget is incomplete. The global fossil fuel industry (production and usage of natural gas, oil and coal) is thought to contribute 15 to 22 per cent of methane emissions to the total atmospheric methane budget. However, questions remain regarding methane emission trends as a result of fossil fuel industrial activity and the contribution to total methane emissions of sources from the fossil fuel industry and from natural geological seepage, which are often co-located. Here we re-evaluate the global methane budget and the contribution of the fossil fuel industry to methane emissions based on long-term global methane and methane carbon isotope records. We compile the largest isotopic methane source signature database so far, including fossil fuel, microbial and biomass-burning methane emission sources. We find that total fossil fuel methane emissions (fossil fuel industry plus natural geological seepage) are not increasing over time, but are 60 to 110 per cent greater than current estimates owing to large revisions in isotope source signatures. We show that this is consistent with the observed global latitudinal methane gradient. After accounting for natural geological methane seepage, we find that methane emissions from natural gas, oil and coal production and their usage are 20 to 60 per cent greater than inventories. Our findings imply a greater potential for the fossil fuel industry to mitigate anthropogenic climate forcing, but we also find that methane emissions from natural gas as a fraction of production have declined from approximately 8 per cent to approximately 2 per cent over the past three decades.

Fossils and living taxa agree on patterns of body mass evolution: a case study with Afrotheria.

Science.gov (United States)

Puttick, Mark N; Thomas, Gavin H

2015-12-22

Most of life is extinct, so incorporating some fossil evidence into analyses of macroevolution is typically seen as necessary to understand the diversification of life and patterns of morphological evolution. Here we test the effects of inclusion of fossils in a study of the body size evolution of afrotherian mammals, a clade that includes the elephants, sea cows and elephant shrews. We find that the inclusion of fossil tips has little impact on analyses of body mass evolution; from a small ancestral size (approx. 100 g), there is a shift in rate and an increase in mass leading to the larger-bodied Paenungulata and Tubulidentata, regardless of whether fossils are included or excluded from analyses. For Afrotheria, the inclusion of fossils and morphological character data affect phylogenetic topology, but these differences have little impact upon patterns of body mass evolution and these body mass evolutionary patterns are consistent with the fossil record. The largest differences between our analyses result from the evolutionary model, not the addition of fossils. For some clades, extant-only analyses may be reliable to reconstruct body mass evolution, but the addition of fossils and careful model selection is likely to increase confidence and accuracy of reconstructed macroevolutionary patterns. © 2015 The Authors.

Wildfire Activity Across the Triassic-Jurassic Boundary in the Polish Basin: Evidence from New Fossil Charcoal & Carbon-isotope Data

Science.gov (United States)

Pointer, R.; Belcher, C.; Hesselbo, S. P.; Hodbod, M.; Pieńkowski, G.

2017-12-01

New fossil charcoal abundance and carbon-isotope data from two sedimentary cores provide new evidence of extreme environmental conditions in the Polish Basin during the Latest Triassic to Earliest Jurassic. Sedimentary cores from the Polish Basin provide an excellent record of terrestrial environmental conditions across the Triassic-Jurassic Boundary, a time of climatic extremes. Previous work has shown that the marine realm was affected by a large perturbation to the carbon cycle across the Triassic-Jurassic Boundary (manifested by large negative and positive carbon-isotope excursions) and limited records of charcoal abundance and organic geochemistry have indicated important changes in fire regime in the coeval ecosystems. Here we present two new carbon-isotope records generated from fossil plant matter across the Triassic-Jurassic boundary, and present new charcoal records. The charcoal abundance data confirm that there was variation in wildfire activity during the Late Triassic-Early Jurassic in the Polish Basin. Peaks in the number of fossil charcoal fragments present occur in both sedimentary cores, and increases in fossil charcoal abundance are linked to wildfires, signalling a short-lived rise in wildfire activity. Fossil charcoal abundance does not appear to be fully controlled by total organic matter content, depositional environment or bioturbation. We argue that increased wildfire activity is likely caused by an increase in ignition of plant material as a result of an elevated number of lightning strikes. Global warming (caused by a massive input of carbon into the atmosphere, as indicated by carbon-isotope data) can increase storm activity, leading to increased numbers of lightning strikes. Previous Triassic-Jurassic Boundary wildfire studies have found fossil charcoal abundance peaks at other northern hemisphere sites (Denmark & Greenland), and concluded that they represent increases in wildfire activity in the earliest Jurassic. Our new charcoal and

The carbon curse: Are fuel rich countries doomed to high CO2 intensities?

International Nuclear Information System (INIS)

Friedrichs, Jörg; Inderwildi, Oliver R.

2013-01-01

The carbon curse is a new theory, related to but distinct from the resource curse. It states that fossil-fuel rich countries tend to follow more carbon-intensive developmental pathways than [if they were] fossil-fuel poor countries, due to a hitherto unappreciated syndrome of causal mechanisms. First, fuel rich countries emit significant amounts of CO 2 in the extraction of fuel and through associated wasteful practices such as gas flaring. Second, easy access to domestic fuel in such countries leads to crowding-out effects for their energy mix and economic structure (for example, abundant oil may displace other fuels from the energy mix and lead to the “Dutch Disease”). Third, fuel abundance weakens the economic incentive to invest in energy efficiency. Fourth, governments in fuel rich countries are under considerable pressure to grant uneconomic fuel consumption subsidies, which further augments the carbon intensity of their economic output. Due to the combined effect of these causal mechanisms, it is genuinely difficult for fuel rich countries to evade carbon-intensive developmental pathways. And yet there are remarkable exceptions like Norway. Such positive outliers indicate that the carbon curse is not destiny when appropriate policies are adopted. - Highlights: • Fuel rich countries appear doomed to high carbon intensity, for four reasons. • First, extractive emissions; and, second, fuel-related crowding-out effects. • Third, weaker incentives to invest in improvements of energy efficiency. • Fourth, significant pressure to grant uneconomic fuel consumption subsidies. • But the carbon curse is not destiny, as indicated by positive outliers like Norway

Biogeographic distribution and metric dental variation of fossil and living orangutans (Pongo spp.).

Science.gov (United States)

Tshen, Lim Tze

2016-01-01

The genus Pongo has a relatively richer Quaternary fossil record than those of the African great apes. Fossil materials are patchy in terms of anatomical parts represented, limited almost exclusively to isolated teeth, jaw and bone fragments. Fossil evidence indicates that the genus Pongo had a broadly continuous distribution across the southern part of the Indomalayan biogeographic region, ranging in time from Early Pleistocene to Holocene: southern China (77 fossil sites), Vietnam (15), Laos (6), Cambodia (2), Thailand (4), Peninsular Malaysia (6), Sumatra (4), Borneo (6) and Java (4). Within this distribution range, there are major geographical gaps with no known orangutan fossils, notably central and southern Indochina, central and southern Thailand, eastern Peninsular Malaysia, northern and southern Sumatra, and Kalimantan. The geological time and place of origin of the genus remain unresolved. Fossil orangutan assemblages usually show greater extent of dental metrical variation than those of modern-day populations. Such variability shown in prehistoric populations has partially contributed to confusion regarding past taxonomic diversity and systematic relationships among extinct and living forms. To date, no fewer than 14 distinct taxa have been identified and named for Pleistocene orangutans. Clear cases suggestive of predation by prehistoric human are few in number, and limited to terminal Pleistocene-Early Holocene sites in Borneo and a Late Pleistocene site in Vietnam.

Sediment core fossils in ancient Lake Ohrid: testing for faunal change since the Last Interglacial

Directory of Open Access Journals (Sweden)

C. Albrecht

2010-11-01

Full Text Available Ancient Lake Ohrid is probably of early Pleistocene or Pliocene origin and amongst the few lakes in the world harbouring an outstanding degree of endemic biodiversity. Although there is a long history of evolutionary research in Lake Ohrid, particularly on molluscs, a mollusc fossil record has been missing up to date. For the first time, gastropod and bivalve fossils are reported from the basal, calcareous part of a 2.6 m long sediment succession (core Co1200 from the north-eastern part of Lake Ohrid. Electron spin resonance (ESR dating of mollusc shells from the same stratigraphic level yielded an age of 130 ± 28 ka. Lithofacies III sediments, i.e. a stratigraphic subdivision comprising the basal succession of core Co1200 between 181.5–263 cm, appeared solid, greyish-white, and consisted almost entirely of silt-sized endogenic calcite (CaCO₃>70% and intact and broken mollusc shells. Here we compare the faunal composition of the thanatocoenosis with recent mollusc associations in Lake Ohrid. A total of 13 mollusc species (9 gastropod and 4 bivalve species could be identified within Lithofacies III sediments. The value of sediment core fossils for reconstructing palaeoenvironmental settings was evaluated and the agreement between sediment and palaeontological proxies was tested.

The study also aims at investigating major faunal changes since the Last Interglacial and searching for signs of extinction events.

The combined findings of the ecological study and the sediment characteristics suggest deposition in a shallow water environment during the Last Interglacial. The fossil fauna exclusively included species also found in the present fauna, i.e. no extinction events are evident for this site since the Last Interglacial. The thanatocoenosis showed the highest similarity with recent Intermediate Layer (5–25 m water depth mollusc assemblages. The demonstrated existence of a mollusc fossil record in Lake Ohrid

Slow and steady: the evolution of cranial disparity in fossil and recent turtles.

Science.gov (United States)

Foth, Christian; Joyce, Walter G

2016-11-30

Turtles (Testudinata) are a diverse group of amniotes that have a rich fossil record that extends back to the Late Triassic, but little is known about global patterns of disparity through time. We here investigate the cranial disparity of 172 representatives of the turtle lineage and their ancestors grouped into 20 time bins ranging from the Late Triassic until the Recent using two-dimensional geometric morphometrics. Three evolutionary phases are apparent in all three anatomical views investigated. In the first phase, disparity increases gradually from the Late Triassic to the Palaeogene with only a minor perturbation at the K/T extinct event. Although global warming may have influenced this increase, we find the Mesozoic fragmentation of Pangaea to be a more plausible factor. Following its maximum, disparity decreases strongly towards the Miocene, only to recover partially towards the Recent. The marked collapse in disparity is likely a result of habitat destruction caused by global drying, combined with the homogenization of global turtle faunas that resulted from increased transcontinental dispersal in the Tertiary. The disparity minimum in the Miocene is likely an artefact of poor sampling. © 2016 The Author(s).

Statistical Models for Inferring Vegetation Composition from Fossil Pollen

Science.gov (United States)

Paciorek, C.; McLachlan, J. S.; Shang, Z.

2011-12-01

Fossil pollen provide information about vegetation composition that can be used to help understand how vegetation has changed over the past. However, these data have not traditionally been analyzed in a way that allows for statistical inference about spatio-temporal patterns and trends. We build a Bayesian hierarchical model called STEPPS (Spatio-Temporal Empirical Prediction from Pollen in Sediments) that predicts forest composition in southern New England, USA, over the last two millenia based on fossil pollen. The critical relationships between abundances of tree taxa in the pollen record and abundances in actual vegetation are estimated using modern (Forest Inventory Analysis) data and (witness tree) data from colonial records. This gives us two time points at which both pollen and direct vegetation data are available. Based on these relationships, and incorporating our uncertainty about them, we predict forest composition using fossil pollen. We estimate the spatial distribution and relative abundances of tree species and draw inference about how these patterns have changed over time. Finally, we describe ongoing work to extend the modeling to the upper Midwest of the U.S., including an approach to infer tree density and thereby estimate the prairie-forest boundary in Minnesota and Wisconsin. This work is part of the PalEON project, which brings together a team of ecosystem modelers, paleoecologists, and statisticians with the goal of reconstructing vegetation responses to climate during the last two millenia in the northeastern and midwestern United States. The estimates from the statistical modeling will be used to assess and calibrate ecosystem models that are used to project ecological changes in response to global change.

Fossil biogeography: a new model to infer dispersal, extinction and sampling from palaeontological data.

Science.gov (United States)

Silvestro, Daniele; Zizka, Alexander; Bacon, Christine D; Cascales-Miñana, Borja; Salamin, Nicolas; Antonelli, Alexandre

2016-04-05

Methods in historical biogeography have revolutionized our ability to infer the evolution of ancestral geographical ranges from phylogenies of extant taxa, the rates of dispersals, and biotic connectivity among areas. However, extant taxa are likely to provide limited and potentially biased information about past biogeographic processes, due to extinction, asymmetrical dispersals and variable connectivity among areas. Fossil data hold considerable information about past distribution of lineages, but suffer from largely incomplete sampling. Here we present a new dispersal-extinction-sampling (DES) model, which estimates biogeographic parameters using fossil occurrences instead of phylogenetic trees. The model estimates dispersal and extinction rates while explicitly accounting for the incompleteness of the fossil record. Rates can vary between areas and through time, thus providing the opportunity to assess complex scenarios of biogeographic evolution. We implement the DES model in a Bayesian framework and demonstrate through simulations that it can accurately infer all the relevant parameters. We demonstrate the use of our model by analysing the Cenozoic fossil record of land plants and inferring dispersal and extinction rates across Eurasia and North America. Our results show that biogeographic range evolution is not a time-homogeneous process, as assumed in most phylogenetic analyses, but varies through time and between areas. In our empirical assessment, this is shown by the striking predominance of plant dispersals from Eurasia into North America during the Eocene climatic cooling, followed by a shift in the opposite direction, and finally, a balance in biotic interchange since the middle Miocene. We conclude by discussing the potential of fossil-based analyses to test biogeographic hypotheses and improve phylogenetic methods in historical biogeography. © 2016 The Author(s).

A high-elevation, multi-proxy biotic and environmental record of MIS 6–4 from the Ziegler Reservoir fossil site, Snowmass Village, Colorado, USA

Energy Technology Data Exchange (ETDEWEB)

Ian M. Miller; Mitchell A. Plummer; Various Others

2014-10-01

In North America, terrestrial records of biodiversity and climate change that span Marine Oxygen Isotope Stage (MIS) 5 are rare. Where found, they provide insight into how the coupling of the ocean–atmosphere system is manifested in biotic and environmental records and how the biosphere responds to climate change. In 2010–2011, construction at Ziegler Reservoir near Snowmass Village, Colorado (USA) revealed a nearly continuous, lacustrine/wetland sedimentary sequence that preserved evidence of past plant communities between ~140 and 55 ka, including all of MIS 5. At an elevation of 2705 m, the Ziegler Reservoir fossil site also contained thousands of well-preserved bones of late Pleistocene megafauna, including mastodons, mammoths, ground sloths, horses, camels, deer, bison, black bear, coyotes, and bighorn sheep. In addition, the site contained more than 26,000 bones from at least 30 species of small animals including salamanders, otters, muskrats, minks, rabbits, beavers, frogs, lizards, snakes, fish, and birds. The combination of macro- and micro-vertebrates, invertebrates, terrestrial and aquatic plant macrofossils, a detailed pollen record, and a robust, directly dated stratigraphic framework shows that high-elevation ecosystems in the Rocky Mountains of Colorado are climatically sensitive and varied dramatically throughout MIS 5

Nuclear versus fossil power plants: evolution of economic evaluation techniques

International Nuclear Information System (INIS)

Thuesen, G.J.

1975-01-01

The purpose of this presentation is to document the evolution of methods used by an electric utility for comparing the economic attractiveness of nuclear versus fossil electric power generation. This process of change is examined as it took place within the Georgia Power Company (GPC), a company spending in the neighborhood of half a billion dollars annually for capital improvements. This study provides a look at the variety of richness of information that can be made available through the application of different methods of economic analysis. In addition, the varied presentations used to disclose relationships between alternatives furnish evidence as to the effectiveness of providing pertinent information in a simple, meaningful manner. It had been generally accepted throughout GPC that nuclear power was economically desirable as an alternative for the production of base-load power. With inflation increasing, its advantage over fossil power appeared to be significantly increasing as the large operating costs of fossil generation seemed to be more vulnerable to inflation than the costs of operating a nuclear facility. An early indication that the company should reevaluate this position was the experience gained with the installation of their first nuclear plant. Here, actual total costs were exceeding their original construction estimates by a factor of two. Thus the question arose ''Does the high capital cost of nuclear generation offset its operating advantages when compared to similar-sized coal-burning plants.'' To answer this question, additional analyses were undertaken

High-resolution leaf-fossil record spanning the Cretaceous/Tertiary boundary

Science.gov (United States)

Johnson, K.R.; Nichols, D.J.; Attrep, M.; Orth, C.J.

1989-01-01

THEORIES that explain the extinctions characterizing the Cretaceous/Tertiary (K/T) boundary1-3 need to be tested by analyses of thoroughly sampled biotas. Palynological studies are the primary means for stratigraphic placement of the terrestrial boundary and for estimates of plant extinction4-12, but have not been combined with quantitative analyses of fossil leaves (megaflora). Megafloral studies complement palynology by representing local floras with assemblages capable of high taxonomic resolution13, but have previously lacked the sample size and stratigraphic spacing needed to resolve latest Cretaceous floral history5,14-18. We have now combined megafloral data from a 100-m-thick composite K/T boundary section in North Dakota with detailed palynological analysis. Here the boundary is marked by a 30% palynofloral extinction coincident with iridium and shocked-mineral anomalies and lies ???2 m above the highest dinosaur remains. The megaflora undergoes a 79% turnover across the boundary, and smaller changes 17- and 25-m below it. This pattern is consistent with latest Cretaceous climatic warming preceding a bolide impact. ?? 1989 Nature Publishing Group.

Study of metal bioaccumulation by nuclear microprobe analysis of algae fossils and living algae cells

International Nuclear Information System (INIS)

Guo, P.; Wang, J.; Li, X.; Zhu, J.; Reinert, T.; Heitmann, J.; Spemann, D.; Vogt, J.; Flagmeyer, R.-H.; Butz, T.

2000-01-01

Microscopic ion-beam analysis of palaeo-algae fossils and living green algae cells have been performed to study the metal bioaccumulation processes. The algae fossils, both single cellular and multicellular, are from the late Neoproterozonic (570 million years ago) ocean and perfectly preserved within a phosphorite formation. The biosorption of the rare earth element ions Nd 3+ by the green algae species euglena gracilis was investigated with a comparison between the normal cells and immobilized ones. The new Leipzig Nanoprobe, LIPSION, was used to produce a proton beam with 2 μm size and 0.5 nA beam current for this study. PIXE and RBS techniques were used for analysis and imaging. The observation of small metal rich spores (<10 μm) surrounding both of the fossils and the living cells proved the existence of some specific receptor sites which bind metal carrier ligands at the microbic surface. The bioaccumulation efficiency of neodymium by the algae cells was 10 times higher for immobilized algae cells. It confirms the fact that the algae immobilization is an useful technique to improve its metal bioaccumulation

Right-handed fossil humans.

Science.gov (United States)

Lozano, Marina; Estalrrich, Almudena; Bondioli, Luca; Fiore, Ivana; Bermúdez de Castro, José-Maria; Arsuaga, Juan Luis; Carbonell, Eudald; Rosas, Antonio; Frayer, David W

2017-11-01

Fossil hominids often processed material held between their upper and lower teeth. Pulling with one hand and cutting with the other, they occasionally left impact cut marks on the lip (labial) surface of their incisors and canines. From these actions, it possible to determine the dominant hand used. The frequency of these oblique striations in an array of fossil hominins documents the typically modern pattern of 9 right- to 1 left-hander. This ratio among living Homo sapiens differs from that among chimpanzees and bonobos and more distant primate relatives. Together, all studies of living people affirm that dominant right-handedness is a uniquely modern human trait. The same pattern extends deep into our past. Thus far, the majority of inferred right-handed fossils come from Europe, but a single maxilla from a Homo habilis, OH-65, shows a predominance of right oblique scratches, thus extending right-handedness into the early Pleistocene of Africa. Other studies show right-handedness in more recent African, Chinese, and Levantine fossils, but the sample compiled for non-European fossil specimens remains small. Fossil specimens from Sima del los Huesos and a variety of European Neandertal sites are predominately right-handed. We argue the 9:1 handedness ratio in Neandertals and the earlier inhabitants of Europe constitutes evidence for a modern pattern of handedness well before the appearance of modern Homo sapiens. © 2017 Wiley Periodicals, Inc.

Two fossil species of Metrosideros (Myrtaceae) from the Oligo-Miocene Golden Fleece locality in Tasmania, Australia.

Science.gov (United States)

Tarran, Myall; Wilson, Peter G; Macphail, Michael K; Jordan, Greg J; Hill, Robert S

2017-06-01

The capsular-fruited genus Metrosideros (Myrtaceae) is one of the most widely distributed flowering plant genera in the Pacific but is extinct in Australia today. The center of geographic origin for the genus and the reason for and timing of its extinction in Australia remain uncertain. We identify fossil Metrosideros fruits from the newly discovered Golden Fleece fossil flora in the Oligo-Miocene of Tasmania, Australia, shedding further light on these problems. Standard paleopalynological techniques were used to date the fossil-bearing sediments. Scanning electron microscopy and an auto-montage camera system were used to take high-resolution images of fossil and extant fruits taken from herbarium specimens. Fossils are identified using a nearest-living-relative approach. The fossil-bearing sediments are palynostratigraphically dated as being Proteacidites tuberculatus Zone Equivalent (ca. 33-16 Ma) in age and provide a confident Oligo-Miocene age for the macrofossils. Two new fossil species of Metrosideros are described and are here named Metrosideros dawsonii sp. nov. and Metrosideros wrightii sp. nov. These newly described fossil species of Metrosideros provide a second record of the genus in the Cenozoic of Australia, placing them in the late Early Oligocene to late Early Miocene. It is now apparent not only that Metrosideros was present in Australia, where the genus is now extinct, but that at least several Metrosideros species were present during the Cenozoic. These fossils further strengthen the case for an Australian origin of the genus. © 2017 Botanical Society of America.

Geologic History of Eocene Stonerose Fossil Beds, Republic, Washington, USA

Directory of Open Access Journals (Sweden)

George E. Mustoe

2015-07-01

Full Text Available Eocene lakebed sediments at Stonerose Interpretive Center in Republic, Washington, USA are one of the most important Cenozoic fossil sites in North America, having gained international attention because of the abundance and diversity of plant, insect, and fish fossils. This report describes the first detailed geologic investigation of this unusual lagerstätten. Strata are gradationally divided into three units: Siliceous shale that originated as diatomite, overlain by laminated mudstone, which is in turn overlain by massive beds of lithic sandstone. The sedimentary sequence records topographic and hydrologic changes that caused a deep lake to become progressively filled with volcaniclastic detritus from earlier volcanic episodes. The location of the ancient lake within an active graben suggests that displacements along the boundary faults were the most likely trigger for changes in depositional processes.

Fossil wood flora from the Siwalik Group of Arunachal Pradesh, India and its climatic and phytogeographic significance

Science.gov (United States)

Srivastava, Gaurav; Mehrotra, R. C.; Srikarni, C.

2018-02-01

The plant fossil records from the Siwalik Group of Arunachal Pradesh, India are far from satisfactory due to remoteness and dense vegetation of the area. We report seven fossil woods of which three belong to the Middle Siwalik (Subansiri Formation), while the rest are from the Upper Siwalik (Kimin Formation). The modern analogues of the fossils from the Middle Siwalik are Lophopetalum littorale (Celastraceae), Afzelia-Intsia and Sindora siamensis (Fabaceae) and from the Upper Siwalik are Miliusa velutina (Annonaceae), Calophyllum tomentosum and Kayea (Calophyllaceae) and Diospyros melanoxylon (Ebenaceae). The dominance of diffuse porosity in the fossil woods indicates a tropical climate with low seasonality (little variation) in temperature, while a high proportion of large vessels and simple perforation plates in the assemblage infer high precipitation during the deposition of the sediments. The aforesaid inference is in strong agreement with the previous quantitative reconstruction based on fossil leaves. Several modern analogues of the fossil taxa are now growing in low latitudes possibly due to an increase in seasonality (increased variation) in temperature caused by the rising Himalaya.

A cosmopolitan late Ediacaran biotic assemblage: new fossils from Nevada and Namibia support a global biostratigraphic link

Science.gov (United States)

Smith, E. F.; Nelson, L. L.; Tweedt, S. M.; Zeng, H.; Workman, Jeremiah B.

2017-01-01

Owing to the lack of temporally well-constrained Ediacaran fossil localities containing overlapping biotic assemblages, it has remained uncertain if the latest Ediacaran (ca 550–541 Ma) assemblages reflect systematic biological turnover or environmental, taphonomic or biogeographic biases. Here, we report new latest Ediacaran fossil discoveries from the lower member of the Wood Canyon Formation in Nye County, Nevada, including the first figured reports of erniettomorphs, Gaojiashania, Conotubus and other problematic fossils. The fossils are spectacularly preserved in three taphonomic windows and occur in greater than 11 stratigraphic horizons, all of which are below the first appearance of Treptichnus pedum and the nadir of a large negative δ13C excursion that is a chemostratigraphic marker of the Ediacaran–Cambrian boundary. The co-occurrence of morphologically diverse tubular fossils and erniettomorphs in Nevada provides a biostratigraphic link among latest Ediacaran fossil localities globally. Integrated with a new report of Gaojiashania from Namibia, previous fossil reports and existing age constraints, these finds demonstrate a distinctive late Ediacaran fossil assemblage comprising at least two groups of macroscopic organisms with dissimilar body plans that ecologically and temporally overlapped for at least 6 Myr at the close of the Ediacaran Period. This cosmopolitan biotic assemblage disappeared from the fossil record at the end of the Ediacaran Period, prior to the Cambrian radiation.

A fossil protein chimera; difficulties in discriminating dinosaur peptide sequences from modern cross-contamination

Science.gov (United States)

Warwood, Stacey; van Dongen, Bart; Kitchener, Andrew C.; Manning, Phillip L.

2017-01-01

A decade ago, reports that organic-rich soft tissue survived from dinosaur fossils were apparently supported by proteomics-derived sequence information of exceptionally well-preserved bone. This initial claim to the sequencing of endogenous collagen peptides from an approximately 68 Myr Tyrannosaurus rex fossil was highly controversial, largely on the grounds of potential contamination from either bacterial biofilms or from laboratory practice. In a subsequent study, collagen peptide sequences from an approximately 78 Myr Brachylophosaurus canadensis fossil were reported that have remained largely unchallenged. However, the endogeneity of these sequences relies heavily on a single peptide sequence, apparently unique to both dinosaurs. Given the potential for cross-contamination from modern bone analysed by the same team, here we extract collagen from bone samples of three individuals of ostrich, Struthio camelus. The resulting LC–MS/MS data were found to match all of the proposed sequences for both the original Tyrannosaurus and Brachylophosaurus studies. Regardless of the true nature of the dinosaur peptides, our finding highlights the difficulty of differentiating such sequences with confidence. Our results not only imply that cross-contamination cannot be ruled out, but that appropriate measures to test for endogeneity should be further evaluated. PMID:28566488

Late Quaternary paleoenvironmental records from the Chatanika River valley near Fairbanks (Alaska)

Science.gov (United States)

Schirrmeister, Lutz; Meyer, Hanno; Andreev, Andrei; Wetterich, Sebastian; Kienast, Frank; Bobrov, Anatoly; Fuchs, Margret; Sierralta, Melanie; Herzschuh, Ulrike

2016-09-01

Perennially-frozen deposits are considered as excellent paleoenvironmental archives similar to lacustrine, deep marine, and glacier records because of the long-term and good preservation of fossil records under stable permafrost conditions. A permafrost tunnel in the Vault Creek Valley (Chatanika River Valley, near Fairbanks) exposes a sequence of frozen deposits and ground ice that provides a comprehensive set of proxies to reconstruct the late Quaternary environmental history of Interior Alaska. The multi-proxy approach includes different dating techniques (radiocarbon-accelerator mass spectrometry [AMS 14C], optically stimulated luminescence [OSL], thorium/uranium radioisotope disequilibria [230Th/U]), as well as methods of sedimentology, paleoecology, hydrochemistry, and stable isotope geochemistry of ground ice. The studied sequence consists of 36-m-thick late Quaternary deposits above schistose bedrock. Main portions of the sequence accumulated during the early and middle Wisconsin periods. The lowermost unit A consists of about 9-m-thick ice-bonded fluvial gravels with sand and peat lenses. A late Sangamon (MIS 5a) age of unit A is assumed. Spruce forest with birch, larch, and some shrubby alder dominated the vegetation. High presence of Sphagnum spores and Cyperaceae pollen points to mires in the Vault Creek Valley. The overlying unit B consists of 10-m-thick alternating fluvial gravels, loess-like silt, and sand layers, penetrated by small ice wedges. OSL dates support a stadial early Wisconsin (MIS 4) age of unit B. Pollen and plant macrofossil data point to spruce forests with some birch interspersed with wetlands around the site. The following unit C is composed of 15-m-thick ice-rich loess-like and organic-rich silt with fossil bones and large ice wedges. Unit C formed during the interstadial mid-Wisconsin (MIS 3) and stadial late Wisconsin (MIS 2) as indicated by radiocarbon ages. Post-depositional slope processes significantly deformed both, ground

Improved age control on early Homo fossils from the upper Burgi Member at Koobi Fora, Kenya

OpenAIRE

Joordens , Josephine ,; Dupont-Nivet , Guillaume; Feibel , Craig ,; Spoor , Fred; Sier , Mark ,; Van Der Lubbe , Jeroen ,; Nielsen , Trine; Knul , Monika ,; Davies , Gareth ,; Vonhof , Hubert ,

2013-01-01

International audience; To address questions regarding the evolutionary origin, radiation and dispersal of the genus Homo, it is crucial to be able to place the occurrence of hominin fossils in a high-resolution chronological framework. The period around 2 Ma (millions of years ago) in eastern Africa is of particular interest as it is at this time that a more substantial fossil record of the genus Homo is first found. Here we combine magnetostratigraphy and strontium (Sr) isotope stratigraphy...

The original colours of fossil beetles.

Science.gov (United States)

McNamara, Maria E; Briggs, Derek E G; Orr, Patrick J; Noh, Heeso; Cao, Hui

2012-03-22

Structural colours, the most intense, reflective and pure colours in nature, are generated when light is scattered by complex nanostructures. Metallic structural colours are widespread among modern insects and can be preserved in their fossil counterparts, but it is unclear whether the colours have been altered during fossilization, and whether the absence of colours is always real. To resolve these issues, we investigated fossil beetles from five Cenozoic biotas. Metallic colours in these specimens are generated by an epicuticular multi-layer reflector; the fidelity of its preservation correlates with that of other key cuticular ultrastructures. Where these other ultrastructures are well preserved in non-metallic fossil specimens, we can infer that the original cuticle lacked a multi-layer reflector; its absence in the fossil is not a preservational artefact. Reconstructions of the original colours of the fossils based on the structure of the multi-layer reflector show that the preserved colours are offset systematically to longer wavelengths; this probably reflects alteration of the refractive index of the epicuticle during fossilization. These findings will allow the former presence, and original hue, of metallic structural colours to be identified in diverse fossil insects, thus providing critical evidence of the evolution of structural colour in this group.

The oldest gibbon fossil (Hylobatidae) from insular Southeast Asia: evidence from Trinil, (East Java, Indonesia), Lower/Middle Pleistocene.

Science.gov (United States)

Ingicco, Thomas; de Vos, John; Huffman, O Frank

2014-01-01

A fossil femur excavated by Eugène Dubois between 1891-1900 in the Lower/Middle Pleistocene bonebed of the Trinil site (Java, Indonesia) was recognised by us as that of a Hylobatidae. The specimen, Trinil 5703 of the Dubois Collection (Leiden, The Netherlands), has the same distinctive form of fossilization that is seen in many of the bonebed fossils from Trinil in the collection. Anatomical comparison of Trinil 5703 to a sample of carnivore and primate femora, supported by morphometric analyses, lead to the attribution of the fossil to gibbon. Trinil 5703 therefore provides the oldest insular record of this clade, one of the oldest known Hylobatidae fossils from Southeast Asia. Because living Hylobatidae only inhabit evergreen rain forests, the paleoenvironment within the river drainage in the greater Trinil area evidently included forests of this kind during the Lower/Middle Pleistocene as revealed here.

The legacy of fossil fuels.

Science.gov (United States)

Armaroli, Nicola; Balzani, Vincenzo

2011-03-01

Currently, over 80% of the energy used by mankind comes from fossil fuels. Harnessing coal, oil and gas, the energy resources contained in the store of our spaceship, Earth, has prompted a dramatic expansion in energy use and a substantial improvement in the quality of life of billions of individuals in some regions of the world. Powering our civilization with fossil fuels has been very convenient, but now we know that it entails severe consequences. We treat fossil fuels as a resource that anyone anywhere can extract and use in any fashion, and Earth's atmosphere, soil and oceans as a dump for their waste products, including more than 30 Gt/y of carbon dioxide. At present, environmental legacy rather than consistence of exploitable reserves, is the most dramatic problem posed by the relentless increase of fossil fuel global demand. Harmful effects on the environment and human health, usually not incorporated into the pricing of fossil fuels, include immediate and short-term impacts related to their discovery, extraction, transportation, distribution, and burning as well as climate change that are spread over time to future generations or over space to the entire planet. In this essay, several aspects of the fossil fuel legacy are discussed, such as alteration of the carbon cycle, carbon dioxide rise and its measurement, greenhouse effect, anthropogenic climate change, air pollution and human health, geoengineering proposals, land and water degradation, economic problems, indirect effects on the society, and the urgent need of regulatory efforts and related actions to promote a gradual transition out of the fossil fuel era. While manufacturing sustainable solar fuels appears to be a longer-time perspective, alternatives energy sources already exist that have the potential to replace fossil fuels as feedstocks for electricity production. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The legacy of fossil fuels

Energy Technology Data Exchange (ETDEWEB)

Armaroli, N.; Balzani, V. [CNR, Bologna (Italy)

2011-03-01

Currently, over 80% of the energy used by mankind comes from fossil fuels. Harnessing coal, oil and gas, the energy resources contained in the store of our spaceship, Earth, has prompted a dramatic expansion in energy use and a substantial improvement in the quality of life of billions of individuals in some regions of the world. Powering our civilization with fossil fuels has been very convenient, but now we know that it entails severe consequences. We treat fossil fuels as a resource that anyone anywhere can extract and use in any fashion, and Earth's atmosphere, soil and oceans as a dump for their waste products, including more than 30 Gt/y of carbon dioxide. At present, environmental legacy rather than consistence of exploitable reserves, is the most dramatic problem posed by the relentless increase of fossil fuel global demand. Harmful effects on the environment and human health, usually not incorporated into the pricing of fossil fuels, include immediate and short-term impacts related to their discovery, extraction, transportation, distribution, and burning as well as climate change that are spread over time to future generations or over space to the entire planet. In this essay, several aspects of the fossil fuel legacy are discussed, such as alteration of the carbon cycle, carbon dioxide rise and its measurement, greenhouse effect, anthropogenic climate change, air pollution and human health, geoengineering proposals, land and water degradation, economic problems, indirect effects on the society, and the urgent need of regulatory efforts and related actions to promote a gradual transition out of the fossil fuel era. While manufacturing sustainable solar fuels appears to be a longer-time perspective, alternatives energy sources already exist that have the potential to replace fossil fuels as feedstocks for electricity production.

Fossils mollusc asemblage found at Zagarzazu, marine Pleistocene, Uruguay

International Nuclear Information System (INIS)

Rojas, A. . E mail: alejandra@fcien.edu.uy

2004-01-01

There are presented the results of the paleoecological analysis of the mollusc assemblage found at Zagarzazu, Colonia department. The fossils are well preserved, arranged in thin shell-beds with some specimens in life position. The assemblage is indicative of higher temperatures than present, and a strong marine influence. It is important to stress that new thermophilic molluscs for the marine Quaternary were found and that this locality represents a new Pleistocene marine record in Uruguay [es

Consequences of elevated temperature and pCO 2 on insect folivory at the ecosystem level: perspectives from the fossil record

OpenAIRE

Currano, Ellen D.; Laker, Rachel; Flynn, Andrew G.; Fogt, Kari K.; Stradtman, Hillary; Wing, Scott L.

2016-01-01

Abstract Paleoecological studies document the net effects of atmospheric and climate change in a natural laboratory over timescales not accessible to laboratory or ecological studies. Insect feeding damage is visible on well?preserved fossil leaves, and changes in leaf damage through time can be compared to environmental changes. We measured percent leaf area damaged on four fossil leaf assemblages from the Bighorn Basin, Wyoming, that range in age from 56.1 to 52.65?million years (Ma). We al...

Phylogenetic distribution of extant richness suggests metamorphosis is a key innovation driving diversification in insects.

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James L Rainford

Full Text Available Insects and their six-legged relatives (Hexapoda comprise more than half of all described species and dominate terrestrial and freshwater ecosystems. Understanding the macroevolutionary processes generating this richness requires a historical perspective, but the fossil record of hexapods is patchy and incomplete. Dated molecular phylogenies provide an alternative perspective on divergence times and have been combined with birth-death models to infer patterns of diversification across a range of taxonomic groups. Here we generate a dated phylogeny of hexapod families, based on previously published sequence data and literature derived constraints, in order to identify the broad pattern of macroevolutionary changes responsible for the composition of the extant hexapod fauna. The most prominent increase in diversification identified is associated with the origin of complete metamorphosis, confirming this as a key innovation in promoting insect diversity. Subsequent reductions are recovered for several groups previously identified as having a higher fossil diversity during the Mesozoic. In addition, a number of recently derived taxa are found to have radiated following the development of flowering plant (angiosperm floras during the mid-Cretaceous. These results reveal that the composition of the modern hexapod fauna is a product of a key developmental innovation, combined with multiple and varied evolutionary responses to environmental changes from the mid Cretaceous floral transition onward.

Textural and mineralogical characteristics of microbial fossils associated with modern and ancient iron (oxyhydr)oxides: terrestrial analogue for sediments in Gale Crater.

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Potter-McIntyre, Sally L; Chan, Marjorie A; McPherson, Brian J

2014-01-01

Iron (oxyhydr)oxide microbial mats in modern to ∼100 ka tufa terraces are present in a cold spring system along Ten Mile Graben, southeastern Utah, USA. Mats exhibit morphological, chemical, and textural biosignatures and show diagenetic changes that occur over millennial scales. The Jurassic Brushy Basin Member of the Morrison Formation in the Four Corners region of the USA also exhibits comparable microbial fossils and iron (oxyhydr)oxide biosignatures in the lacustrine unit. Both the modern spring system and Brushy Basin Member represent alkaline, saline, groundwater-fed systems and preserve diatoms and other similar algal forms with cellular elaboration. Two distinct suites of elements (1. C, Fe, As and 2. C, S, Se, P) are associated with microbial fossils in modern and ancient iron (oxyhydr)oxides and may be potential markers for biosignatures. The presence of ferrihydrite in ∼100 ka fossil microbial mats and Jurassic rocks suggests that this thermodynamically unstable mineral may also be a potential biomarker. One of the most extensive sedimentary records on Mars is exposed in Gale Crater and consists of non-acidic clays and sulfates possibly of lacustrine origin. These terrestrial iron (oxyhydr)oxide examples are a valuable analogue because of similar iron- and clay-rich host rock compositions and will help (1) understand diagenetic processes in a non-acidic, saline lacustrine environment such as the sedimentary rocks in Gale Crater, (2) document specific biomediated textures, (3) demonstrate how biomediated textures might persist or respond to diagenesis over time, and (4) provide a ground truth library of textures to explore and compare in extraterrestrial iron (oxyhydr)oxides, where future explorations hope to detect past evidence of life.

Soft-Bodied Fossils Are Not Simply Rotten Carcasses - Toward a Holistic Understanding of Exceptional Fossil Preservation: Exceptional Fossil Preservation Is Complex and Involves the Interplay of Numerous Biological and Geological Processes.

Science.gov (United States)

Parry, Luke A; Smithwick, Fiann; Nordén, Klara K; Saitta, Evan T; Lozano-Fernandez, Jesus; Tanner, Alastair R; Caron, Jean-Bernard; Edgecombe, Gregory D; Briggs, Derek E G; Vinther, Jakob

2018-01-01

Exceptionally preserved fossils are the product of complex interplays of biological and geological processes including burial, autolysis and microbial decay, authigenic mineralization, diagenesis, metamorphism, and finally weathering and exhumation. Determining which tissues are preserved and how biases affect their preservation pathways is important for interpreting fossils in phylogenetic, ecological, and evolutionary frameworks. Although laboratory decay experiments reveal important aspects of fossilization, applying the results directly to the interpretation of exceptionally preserved fossils may overlook the impact of other key processes that remove or preserve morphological information. Investigations of fossils preserving non-biomineralized tissues suggest that certain structures that are decay resistant (e.g., the notochord) are rarely preserved (even where carbonaceous components survive), and decay-prone structures (e.g., nervous systems) can fossilize, albeit rarely. As we review here, decay resistance is an imperfect indicator of fossilization potential, and a suite of biological and geological processes account for the features preserved in exceptional fossils. © 2017 The Authors. BioEssays Published by WILEY Periodicals, Inc.

Uranium concentrations in fossils measured by SIMS

International Nuclear Information System (INIS)

Uyeda, Chiaki; Okano, Jun

1988-01-01

Semiquantitative analyses of uranium in fossil bones and teeth were carried out by SIMS. The results show a tendency that uranium concentrations in the fossils increase with the ages of the fossils. It is noticed that fossil bones and teeth having uranium concentration of more than several hundred ppm are not rare. (author)

The oldest fossil record of the megamouth shark from the late Eocene of Denmark and comments on the enigmatic megachasmid origin

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Kenshu Shimada

2016-12-01

Full Text Available The megamouth shark (Lamniformes: Megachasmidae has sporadic occurrences both in the present-day oceans and in the fossil record. In this paper, we describe a new megachasmid, Megachasma alisonae sp. nov., on the basis of a morphologically distinct tooth collected from the Pyt Member of the late Eocene Søvind Marl Formation at Moesgård Strand in Denmark, that represents the geologically oldest known Megachasma. The tooth likely came from an individual that measured somewhere between 1.3 and 3.5 m long, and its morphology and chipped cusp tips suggest that it possibly fed on macro-zooplankton and small fishes that had hard skeletal components. Its occurrence in the mid-Priabonian Pyt Member at least suggests that the shark inhabited a relatively deep, open marine environment about 36 Ma ago. This Eocene specimen is significant because it illustrates the dental condition of early megachasmids, which is distinctively odontaspidid-like morphologically.

Hummingbird with modern feathering: an exceptionally well-preserved Oligocene fossil from southern France

Science.gov (United States)

Louchart, Antoine; Tourment, Nicolas; Carrier, Julie; Roux, Thierry; Mourer-Chauviré, Cécile

2008-02-01

Hummingbirds (Trochilidae) today have an exclusively New World distribution, but their pre-Pleistocene fossil record comes from Europe only. In this study, we describe an exceptionally preserved fossil hummingbird from the early Oligocene of southeastern France. The specimen is articulated, with a completely preserved beak and feathering. Osteological characters allow to identify it as Eurotrochilus sp. This genus is a stem group representative of Trochilidae and was recently described from the early Oligocene of southern Germany. The new fossil reveals that these European Trochilidae were remarkably modern in size, skeletal proportions and the shape of the wing, tail and beak and hyoid bones. These features confirm the early acquisition of the abilities of hovering and nectarivory in hummingbirds, probably before the Oligocene. In several morphological characteristics, they resemble members of the ‘true hummingbirds’ (subfamily Trochilinae) and differ from hermits (Phaethornithinae). These features, which include a short and square tail and a moderately long, almost straight beak, appear to be primitive within the family Trochilidae.

Oil-rich seeds from prehistoric contextsin southern Scandinavia – reflections on archaeobotanical records of fl ax, hemp, gold of pleasure, and corn spurrey

DEFF Research Database (Denmark)

Karg, Sabine

2012-01-01

. Although archaeobotanical records of oil plants are in most cases found in small numbers, they are often abundant at excavations in southern Scandinavia. This paper presents a diachronic review of plant records of fl ax (Linum usitatissimum L.) and hemp (Cannabis sativa L.), both known for the dual use...... as to whether corn spurrey had been a cultivar or if the seeds had been collected from wild populations. KEYWORDS: Archaeobotany, oil-rich seeds, fl ax, hemp, gold of pleasure, corn spurrey, southern Scandinavia...

Triassic leech cocoon from Antarctica contains fossil bell animal

DEFF Research Database (Denmark)

Bomfleur, Benjamin; Kerp, Hans; Taylor, Thomas N.

2012-01-01

. The microfossil consists of a helically contractile stalk that attaches to a main body with a peristomial feeding apparatus and a large C-shaped macronucleus. It agrees in every aspect with the living bell animals, such as Vorticella. Vorticellids and similar peritrichs are vital constituents of aquatic...... ecosystems worldwide, but so far have lacked any fossil record. This discovery offers a glimpse of ancient soft-bodied protozoan biotas, and also highlights the potential of clitellate cocoons as microscopic "conservation traps" comparable to amber....

A review and phylogeny of Scarabaeine dung beetle fossils (Coleoptera: Scarabaeidae: Scarabaeinae, with the description of two Canthochilum species from Dominican amber

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Sergei Tarasov

2016-05-01

Full Text Available Despite the increasing rate of systematic research on scarabaeine dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae, their fossil record has remained largely unrevised. In this paper, we review all 33 named scarabaeine fossils and describe two new species from Dominican amber (Canthochilum alleni sp.n., Canthochilum philipsivieorum sp.n.. We provide a catalogue of all fossil Scarabaeinae and evaluate their assignment to this subfamily, based primarily on the original descriptions but also, where possible, by examining the type specimens. We suggest that only 21 fossil taxa can be reliably assigned to the Scarabaeinae, while the remaining 14 should be treated as doubtful Scarabaeinae. The doubtful scarabaeines include the two oldest dung beetle fossils known from the Cretaceous and we suggest excluding them from any assessments of the minimum age of scarabaeine dung beetles. The earliest reliably described scarabaeine fossil appears to be Lobateuchus parisii, known from Oise amber (France, which shifts the minimum age of the Scarabaeinae to the Eocene (53 Ma. We scored the best-preserved fossils, namely Lobateuchus and the two Canthochilum species described herein, into the character matrix used in a recent morphology-based study of dung beetles, and then inferred their phylogenetic relationships with Bayesian and parsimony methods. All analyses yielded consistent phylogenies where the two fossil Canthochilum are placed in a clade with the extant species of Canthochilum, and Lobateuchus is recovered in a clade with the extant genera Ateuchus and Aphengium. Additionally, we evaluated the distribution of dung beetle fossils in the light of current global dung beetle phylogenetic hypotheses, geological time and biogeography. The presence of only extant genera in the late Oligocene and all later records suggests that the main present-day dung beetle lineages had already been established by the late Oligocene–mid Miocene.

A fossil protein chimera; difficulties in discriminating dinosaur peptide sequences from modern cross-contamination.

Science.gov (United States)

Buckley, Michael; Warwood, Stacey; van Dongen, Bart; Kitchener, Andrew C; Manning, Phillip L

2017-05-31

A decade ago, reports that organic-rich soft tissue survived from dinosaur fossils were apparently supported by proteomics-derived sequence information of exceptionally well-preserved bone. This initial claim to the sequencing of endogenous collagen peptides from an approximately 68 Myr Tyrannosaurus rex fossil was highly controversial, largely on the grounds of potential contamination from either bacterial biofilms or from laboratory practice. In a subsequent study, collagen peptide sequences from an approximately 78 Myr Brachylophosaurus canadensis fossil were reported that have remained largely unchallenged. However, the endogeneity of these sequences relies heavily on a single peptide sequence, apparently unique to both dinosaurs. Given the potential for cross-contamination from modern bone analysed by the same team, here we extract collagen from bone samples of three individuals of ostrich, Struthio camelus The resulting LC-MS/MS data were found to match all of the proposed sequences for both the original Tyrannosaurus and Brachylophosaurus studies. Regardless of the true nature of the dinosaur peptides, our finding highlights the difficulty of differentiating such sequences with confidence. Our results not only imply that cross-contamination cannot be ruled out, but that appropriate measures to test for endogeneity should be further evaluated. © 2017 The Authors.

The origin of snakes: revealing the ecology, behavior, and evolutionary history of early snakes using genomics, phenomics, and the fossil record.

Science.gov (United States)

Hsiang, Allison Y; Field, Daniel J; Webster, Timothy H; Behlke, Adam D B; Davis, Matthew B; Racicot, Rachel A; Gauthier, Jacques A

2015-05-20

The highly derived morphology and astounding diversity of snakes has long inspired debate regarding the ecological and evolutionary origin of both the snake total-group (Pan-Serpentes) and crown snakes (Serpentes). Although speculation abounds on the ecology, behavior, and provenance of the earliest snakes, a rigorous, clade-wide analysis of snake origins has yet to be attempted, in part due to a dearth of adequate paleontological data on early stem snakes. Here, we present the first comprehensive analytical reconstruction of the ancestor of crown snakes and the ancestor of the snake total-group, as inferred using multiple methods of ancestral state reconstruction. We use a combined-data approach that includes new information from the fossil record on extinct crown snakes, new data on the anatomy of the stem snakes Najash rionegrina, Dinilysia patagonica, and Coniophis precedens, and a deeper understanding of the distribution of phenotypic apomorphies among the major clades of fossil and Recent snakes. Additionally, we infer time-calibrated phylogenies using both new 'tip-dating' and traditional node-based approaches, providing new insights on temporal patterns in the early evolutionary history of snakes. Comprehensive ancestral state reconstructions reveal that both the ancestor of crown snakes and the ancestor of total-group snakes were nocturnal, widely foraging, non-constricting stealth hunters. They likely consumed soft-bodied vertebrate and invertebrate prey that was subequal to head size, and occupied terrestrial settings in warm, well-watered, and well-vegetated environments. The snake total-group - approximated by the Coniophis node - is inferred to have originated on land during the middle Early Cretaceous (~128.5 Ma), with the crown-group following about 20 million years later, during the Albian stage. Our inferred divergence dates provide strong evidence for a major radiation of henophidian snake diversity in the wake of the Cretaceous-Paleogene (K

Sustainability of Fossil Fuels

Science.gov (United States)

Lackner, K. S.

2002-05-01

For a sustainable world economy, energy is a bottleneck. Energy is at the basis of a modern, technological society, but unlike materials it cannot be recycled. Energy or more precisely "negentropy" (the opposite of entropy) is always consumed. Thus, one either accepts the use of large but finite resources or must stay within the limits imposed by dilute but self-renewing resources like sunlight. The challenge of sustainable energy is exacerbated by likely growth in world energy demand due to increased population and increased wealth. Most of the world still has to undergo the transition to a wealthy, stable society with the near zero population growth that characterizes a modern industrial society. This represents a huge unmet demand. If ten billion people were to consume energy like North Americans do today, world energy demand would be ten times higher. In addition, technological advances while often improving energy efficiency tend to raise energy demand by offering more opportunity for consumption. Energy consumption still increases at close to the 2.3% per year that would lead to a tenfold increase over the course of the next century. Meeting future energy demands while phasing out fossil fuels appears extremely difficult. Instead, the world needs sustainable or nearly sustainable fossil fuels. I propose the following definition of sustainable under which fossil fuels would well qualify: The use of a technology or resource is sustainable if the intended and unintended consequences will not force its abandonment within a reasonable planning horizon. Of course sustainable technologies must not be limited by resource depletion but this is only one of many concerns. Environmental impacts, excessive land use, and other constraints can equally limit the use of a technology and thus render it unsustainable. In the foreseeable future, fossil fuels are not limited by resource depletion. However, environmental concerns based on climate change and other environmental

Trace-fossil assemblages with a new ichnogenus in "spotted"

Science.gov (United States)

Šimo, Vladimír; Tomašových, Adam

2013-10-01

Highly-bioturbated "spotted" limestones and marls (Fleckenmergel-Fleckenkalk facies) of the Early Jurassic, which were deposited in broad and recurrent deep-shelf habitats of the Northern Tethys, are characterized by rare benthic carbonate-producing macroinvertebrates. To address this paradox, we analyse trace-fossil assemblages in a ~85 m-thick succession of Pliensbachian spotted deposits (Zliechov Basin, Western Carpathians). They are dominated by infaunal and semi-infaunal deposit-feeders, with 9 ichnogenera and pyritized tubes of the semi-infaunal foraminifer Bathysiphon, being dominated by Chondrites, Lamellaeichnus (new ichnogenus), and Teichichnus. Lamellaeichnus, represented by a horizontal basal cylindrical burrow and an upper row of stacked convex-up gutters, was produced by a mobile deposit-feeder inhabiting shallow tiers because it is crossed by most other trace fossils. We show that the spotty appearance of the deposits is generated by a mixture of (1) dark, organic-rich shallow- and deep-tier traces (TOC = 0.16-0.36), and (2) light grey, organic-poor mottled or structurless sediment (TOC = 0.09-0.22). The higher TOC in shallow-tier burrows of Lamellaeichnus demonstrates that uppermost sediment layers were affected by poor redox cycling. Such conditions imply a limited mixed-layer depth and inefficient nutrient recycling conditioned by hypoxic bottom-waters, allowed by poor circulation and high sedimentation rates in depocenters of the Zliechov Basin. Hypoxic conditions are further supported by (1) dominance of trace-fossils produced by infaunal deposit feeders, (2) high abundance of hypoxiatolerant agglutinated foraminifer Bathysiphon, and (3) high abundance of Chondrites with ~0.5 mm-sized branches. Oxygen-deficient bottom-conditions can thus simultaneously explain the rarity of benthic carbonate-producing macroinvertebrates and high standing abundance of tolerant soft-shell and agglutinated organisms in spotted deposits.

First record of lobed trace fossils in Brazil's Upper Cretaceous paleosols: Rhizoliths or evidence of insects and their social behavior?

Science.gov (United States)

Luciano do Nascimento, Diego; Batezelli, Alessandro; Bernardes Ladeira, Francisco Sérgio

2017-11-01

This is the first report of trace fossils potentially associated with insect social behavior in sandy and well-drained paleosols of the Upper Cretaceous continental sequence of Brazil. The trace fossils consist of dozens of lobed and vertical structures cemented by CaCO3 and preserved mainly in full relief in paleosols of the Marilia Formation (Bauru Basin) in the state of Minas Gerais. The described ichnofossils are predominantly vertical, up to 2 m long, and are composed of horizontal lobed structures connected by vertical tunnel-like structures that intersect in the center and at the edges. The lobed structures range from 3 to 15 cm long and 2-6 cm thick. Two different hypotheses are analyzed to explain the origin of the trace fossils; the less probable one is that the structures are laminar calcretes associated with rhizoliths and rhizoconcretions. The hypothesis involving social insects was considered because the trace fossils described herein partially resemble a modern ant nest and the ichnofossil Daimoniobarax. The micromorphological analysis of the lobed and tunnel-like structures indicates modifications of the walls, such as the presence of inorganic fluidized linings, dark linings and oriented grains, supporting the hypothesis that they are chambers and shafts. The architecture and size of the reported nests suggest the possibility that social insect colonies existed during the Maastrichtian and are direct evidence of the social behavior and reproductive strategies of the Cretaceous pedofauna.

A WELL PRESERVED SKELETON OF THE FOSSIL SHARK COSMOPOLITODUS HASTALIS FROM THE LATE MIOCENE OF PERU, FEATURING FISH REMAINS AS FOSSILIZED STOMACH CONTENTS

Directory of Open Access Journals (Sweden)

ALBERTO COLLARETA

2017-01-01

Full Text Available Both the preservation of the poorly mineralized skeleton of sharks and the preservation of stomach contents are rarely observed in the fossil record. Here we report on a partial skeleton of a lamniform shark, including portions of the visceral arches and the anterior segment of the vertebral column, collected from the late Miocene beds of the Pisco Formation exposed at Cerro Yesera (Ica Desert, South Peru. Based on the morphology of the preserved teeth, this specimen was determined as a juvenile of the extinct lamnid species Cosmopolitodus hastalis. The shark skeleton includes remains of fish (featuring a pilchard determined as Sardinops sp. cf. S. sagax in the abdominal region. These fish remains are interpreted herein as the fossilized stomach contents of the shark. For the first time, piscivory is demonstrated in a juvenile individual of Cosmopolitodus hastalis. This result is consistent with the current knowledge about the feeding habits of immature individuals of extant lamniform shark species (including Carcharodon carcharias and Isurus oxyrinchus. Our report further outlines the fundamental role of schooling pilchards in the late Miocene trophic chains of the highly productive coastal waters off present South Peru. Moreover, the find of this well preserved shark skeleton strengthens the qualification of the Pisco Formation as a Fossil-Lagerstätte, and emphasizes the role of early mineralization processes in cases of exceptional preservation.

Deconvolution of the tree ring based delta13C record

International Nuclear Information System (INIS)

Peng, T.; Broecker, W.S.; Freyer, H.D.; Trumbore, S.

1983-01-01

We assumed that the tree-ring based 13 C/ 12 C record constructed by Freyer and Belacy (1983) to be representative of the fossil fuel and forest-soil induced 13 C/ 12 C change for atmospheric CO 2 . Through the use of a modification of the Oeschger et al. ocean model, we have computed the contribution of the combustion of coal, oil, and natural gas to this observed 13 C/ 12 C change. A large residual remains when the tree-ring-based record is corrected for the contribution of fossil fuel CO 2 . A deconvolution was performed on this residual to determine the time history and magnitude of the forest-soil reservoir changes over the past 150 years. Several important conclusions were reached. (1) The magnitude of the integrated CO 2 input from these sources was about 1.6 times that from fossil fuels. (2) The forest-soil contribution reached a broad maximum centered at about 1900. (3) Over the 2 decade period covered by the Mauna Loa atmospheric CO 2 content record, the input from forests and soils was about 30% that from fossil fuels. (4) The 13 C/ 12 C trend over the last 20 years was dominated by the input of fossil fuel CO 2 . (5) The forest-soil release did not contribute significantly to the secular increase in atmospheric CO 2 observed over the last 20 years. (6) The pre-1850 atmospheric p2 values must have been in the range 245 to 270 x 10 -6 atmospheres

Phylogeny and Divergence Times of Lemurs Inferred with Recent and Ancient Fossils in the Tree.

Science.gov (United States)

Herrera, James P; Dávalos, Liliana M

2016-09-01

Paleontological and neontological systematics seek to answer evolutionary questions with different data sets. Phylogenies inferred for combined extant and extinct taxa provide novel insights into the evolutionary history of life. Primates have an extensive, diverse fossil record and molecular data for living and extinct taxa are rapidly becoming available. We used two models to infer the phylogeny and divergence times for living and fossil primates, the tip-dating (TD) and fossilized birth-death process (FBD). We collected new morphological data, especially on the living and extinct endemic lemurs of Madagascar. We combined the morphological data with published DNA sequences to infer near-complete (88% of lemurs) time-calibrated phylogenies. The results suggest that primates originated around the Cretaceous-Tertiary boundary, slightly earlier than indicated by the fossil record and later than previously inferred from molecular data alone. We infer novel relationships among extinct lemurs, and strong support for relationships that were previously unresolved. Dates inferred with TD were significantly older than those inferred with FBD, most likely related to an assumption of a uniform branching process in the TD compared with a birth-death process assumed in the FBD. This is the first study to combine morphological and DNA sequence data from extinct and extant primates to infer evolutionary relationships and divergence times, and our results shed new light on the tempo of lemur evolution and the efficacy of combined phylogenetic analyses. © The Author(s) 2016. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Multiple Nebular Gas Reservoirs Recorded by Oxygen Isotope Variation in a Spinel-rich CAI in CO3 MIL 090019

Science.gov (United States)

Simon, J. I.; Simon, S. B.; Nguyen, A. N.; Ross, D. K.; Messenger, S.

2017-01-01

We conducted NanoSIMS O-isotopic imaging of a primitive spinel-rich CAI spherule (27-2) from the MIL 090019 CO3 chondrite. Inclusions such as 27-2 are proposed to record inner nebula processes during an epoch of rapid solar nebula evolution. Mineralogical and textural analyses suggest that this CAI formed by high temperature reactions, partial melting, and condensation. This CAI exhibits radial O-isotopic heterogeneity among multiple occurrences of the same mineral, reflecting interactions with distinct nebular O-isotopic reservoirs.

Study of two new methods of geochronometry: dating method of carbonaceous formations by U-series disequilibrium gamma spectrometry; ESR dating method of rich U-content fossil dental enamel

International Nuclear Information System (INIS)

Ma, Jean-Luc

1984-01-01

First, the U-series disequilibrium dating method was re-examined using non-destructive γ-spectrometry. A new low-background (≤ 10 ppb U- equivalent) Ge-HP γ-spectrometer has been used to date travertine with small U-content (∼ 0.1 ppm) and low (≤ 5%) Th/U , content, by comparison with old-limestone γ-spectra. Second, a new ESR dating method has been developed using fossil dental enamel which is rich in U-content (10 - 100 ppm). Both methods were applied to Arago Cave (Tautavel, France): - with an ionium-age of 120 ka (10%), the upper travertine seems to have been set up during the Riss-deglaciation period. - the high (∼ 50%) Th/U-content samples of the intermediate travertine are un-datable. - the ESR-age of EQUUS mosbachensis enamel is 400 ka (10%) for the G-soil of Arago. XXI H. erectus, and 600 ka (10%) for the Q-soil above (- 1 m) of the lower travertine of which Io-age is older than 350 ka. (author)

Rare earth element composition of Paleogene vertebrate fossils from Toadstool Geologic Park, Nebraska, USA

Energy Technology Data Exchange (ETDEWEB)

Grandstaff, D.E., E-mail: grand@temple.edu [Department of Earth and Environmental Science, Temple University, Philadelphia, PA 19122 (United States); Terry, D.O. [Department of Earth and Environmental Science, Temple University, Philadelphia, PA 19122 (United States)

2009-04-15

Fossil bones and teeth from terrestrial environments encode unique rare earth and trace element (REE and TE) signatures as a function of redox conditions, pH, concentrations of complexing ligands, and water-colloid interactions. This signature is set early in the fossilization process and serves as a paleoenvironmental and paleoclimatic proxy. These signatures can also be used to interpret temporal and spatial averaging within vertebrate accumulations, and can help relocate displaced fossil bones back into stratigraphic context. Rare earth elements in vertebrate fossils from upper Eocene and Oligocene strata of Toadstool Geologic Park, northwestern Nebraska, record mixing and evolution of Paleogene vadose or groundwaters and variations in paleoenvironments. REE signatures indicate that HREE-enriched alkaline groundwater reacted with LREE- and MREE-enriched sediments to produce 3-component mixtures. REE signatures become increasingly LREE- and MREE-enriched toward the top of the studied section as the paleoenvironment became cooler and drier, suggesting that REE signatures may be climate proxies. Time series analysis suggests that REE ratios are influenced by cycles of ca. 1050, 800, 570, 440, and 225 ka, similar to some previously determined Milankovitch astronomical and climate periodicities.

Boom and bust: ancient and recent diversification in bichirs (Polypteridae: Actinopterygii), a relictual lineage of ray-finned fishes.

Science.gov (United States)

Near, Thomas J; Dornburg, Alex; Tokita, Masayoshi; Suzuki, Dai; Brandley, Matthew C; Friedman, Matt

2014-04-01

Understanding the history that underlies patterns of species richness across the Tree of Life requires an investigation of the mechanisms that not only generate young species-rich clades, but also those that maintain species-poor lineages over long stretches of evolutionary time. However, diversification dynamics that underlie ancient species-poor lineages are often hidden due to a lack of fossil evidence. Using information from the fossil record and time calibrated molecular phylogenies, we investigate the history of lineage diversification in Polypteridae, which is the sister lineage of all other ray-finned fishes (Actinopterygii). Despite originating at least 390 million years (Myr) ago, molecular timetrees support a Neogene origin for the living polypterid species. Our analyses demonstrate polypterids are exceptionally species depauperate with a stem lineage duration that exceeds 380 million years (Ma) and is significantly longer than the stem lineage durations observed in other ray-finned fish lineages. Analyses of the fossil record show an early Late Cretaceous (100.5-83.6 Ma) peak in polypterid genus richness, followed by 60 Ma of low richness. The Neogene species radiation and evidence for high-diversity intervals in the geological past suggest a "boom and bust" pattern of diversification that contrasts with common perceptions of relative evolutionary stasis in so-called "living fossils." © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

Progress in ESR dating of fossils

International Nuclear Information System (INIS)

Ikeya, M.

1983-01-01

In this review the progress of ESR dating is briefly described together with its historical development. Examples of fossil dating include shells and corals in geological sediments, fossil bones and teeth in anthropology and fossil woods in geology. The total dose of natural radiation (TD) equivalent to the archaeological dose in TL dating was obtained by the additive dose method. Initially, the TDs were plotted against the known ages; using the apparent annual dose-rate thus obtained gives the ESR age within a factor of 2 or 3 for a fossil. Precise assessment of the radiation environment was made later taking the disequilibrium of uranium series disintegration into account. ESR ages of corals agreed well with those obtained by radiocarbon and uranium-thorium methods. The time-independent accumulation rate or a linear accumulation or uranium was adopted as a first sensible model for the opensystem fossil bones: the relation between the TD and the age explains the ages of anthropologically important bones. Lastly, geological assessment of fossil woods was made by ESR based on the organic radicals and electron traps in the silicified part. (author)

A new commelinid monocot seed fossil from the early Eocene previously identified as Solanaceae.

Science.gov (United States)

Särkinen, Tiina; Kottner, Sören; Stuppy, Wolfgang; Ahmed, Farah; Knapp, Sandra

2018-01-01

Fossils provide minimum age estimates for extant lineages. Here we critically evaluate Cantisolanum daturoides Reid & Chandler and two other early putative seed fossils of Solanaceae, an economically important plant family in the Asteridae. Three earliest seed fossil taxa of Solanaceae from the London Clay Formation (Cantisolanum daturoides) and the Poole and Branksome Sand Formations (Solanum arnense Chandler and Solanispermum reniforme Chandler) were studied using x-ray microcomputed tomography (MCT) and scanning electron microscopy (SEM). The MCT scans of Cantisolanum daturoides revealed a high level of pyrite preservation at the cellular level. Cantisolanum daturoides can be clearly excluded from Solanaceae and has more affinities to the commelinid monocots based on a straight longitudinal axis, a prominent single layer of relatively thin-walled cells in the testa, and a clearly differentiated micropyle surrounded by radially elongated and inwardly curved testal cells. While the MCT scans show no internal preservation in Solanum arnense and Solanispermum reniforme, SEM images show the presence of several characteristics that allow the placement of these taxa at the stem node of Solanaceae. Cantisolanum daturoides is likely a member of commelinid monocots and not Solanaceae as previously suggested. The earliest fossil record of Solanaceae is revised to consist of fruit fossil with inflated calyces from the early Eocene of Patagonia (52 Ma) and fossilized seeds from the early to mid-Eocene of Europe (48-46 Ma). The new identity for Cantisolanum daturoides does not alter a late Cretaceous minimum age for commelinids. © 2018 Botanical Society of America.

Taphonomy of the fossil insects of the middle Eocene Kishenehn Formation

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Dale E. Greenwalt

2015-12-01

Full Text Available The lacustrine oil shales of the Coal Creek Member of the Kishenehn Formation in northwestern Montana comprise a relatively unstudied middle Eocene fossil insect locality. Herein, we detail the stratigraphic position of the fossiliferous unit, describe the insect fauna of the Coal Creek locality and document its bias towards very small but remarkably pre-served insects. In addition, the depositional environment is examined and the mineral constituents of the laminations that comprise the varves of the Kishenehn oil shale are defined. Fifteen orders of insects have been recorded with the majority of all insects identified as aquatic with the families Chironomidae (Diptera and Corixidae (Hemiptera dominant. The presence of small aquatic insects, many of which are immature, the intact nature of >90% of the fossil insects and the presence of Daphnia ephippia, all indicate that the depositional environment was the shallow margin of a large freshwater lake. The fossil insects occur within fossilized microbial mat layers that comprise the bedding planes of the oil shale. Unlike the fossiliferous shales of the Florissant and Okanagan Highlands, the mats are not a product of diatomaceous algae nor are diatom frustules a component of the sediments or the varve structure. Instead, the varves are composed of very fine eolian siliciclastic silt grains overlaid with non-diatomaceous, possibly cyanobacteria-derived microbial mats which contain distinct traces of polyaromatic hydrocarbons. A distinct third layer composed of essentially pure calcite is present in the shale of some exposures and is presumably derived from the seasonal warming-induced precipitation of carbonate from the lake’s waters. The Coal Creek locality presents a unique opportunity to study both very small middle Eocene insects not often preserved as compression fossils in most Konservat-Lagerstätte and the processes that led to their preservation.

Evaluation of hard fossil fuel

International Nuclear Information System (INIS)

Zivkovic, S.; Nuic, J.

1999-01-01

Because of its inexhaustible supplies hard fossil fuel will represent the pillar of the power systems of the 21st century. Only high-calorie fossil fuels have the market value and participate in the world trade. Low-calorie fossil fuels ((brown coal and lignite) are fuels spent on the spot and their value is indirectly expressed through manufactured kWh. For the purpose of determining the real value of a tonne of low-calorie coal, the criteria that help in establishing the value of a tonne of hard coal have to be corrected and thus evaluated and assessed at the market. (author)

Organic and mineral imprints in fossil photosynthetic mats of an East Antarctic lake.

Science.gov (United States)

Lepot, K; Compère, P; Gérard, E; Namsaraev, Z; Verleyen, E; Tavernier, I; Hodgson, D A; Vyverman, W; Gilbert, B; Wilmotte, A; Javaux, E J

2014-09-01

Lacustrine microbial mats in Antarctic ice-free oases are considered modern analogues of early microbial ecosystems as their primary production is generally dominated by cyanobacteria, the heterotrophic food chain typically truncated due to extreme environmental conditions, and they are geographically isolated. To better understand early fossilization and mineralization processes in this context, we studied the microstructure and chemistry of organo-mineral associations in a suite of sediments 50-4530 cal. years old from a lake in Skarvsnes, Lützow Holm Bay, East Antarctica. First, we report an exceptional preservation of fossil autotrophs and their biomolecules on millennial timescales. The pigment scytonemin is preserved inside cyanobacterial sheaths. As non-pigmented sheaths are also preserved, scytonemin likely played little role in the preservation of sheath polysaccharides, which have been cross-linked by ether bonds. Coccoids preserved thylakoids and autofluorescence of pigments such as carotenoids. This exceptional preservation of autotrophs in the fossil mats argues for limited biodegradation during and after deposition. Moreover, cell-shaped aggregates preserved sulfur-rich nanoglobules, supporting fossilization of instable intracellular byproducts of chemotrophic or phototrophic S-oxidizers. Second, we report a diversity of micro- to nanostructured CaCO3 precipitates intimately associated with extracellular polymeric substances, cyanobacteria, and/or other prokaryotes. Micro-peloids Type 1 display features that distinguish them from known carbonates crystallized in inorganic conditions: (i) Type 1A are often filled with globular nanocarbonates and/or surrounded by a fibrous fringe, (ii) Type 1B are empty and display ovoid to wrinkled fringes of nanocrystallites that can be radially oriented (fibrous or triangular) or multilayered, and (iii) all show small-size variations. Type 2 rounded carbonates 1-2 μm in diameter occurring inside autofluorescent

Fossil energy use and the environment

International Nuclear Information System (INIS)

Sage, P.W.

1994-01-01

Energy demand projections indicate that fossil energy will provide some ninety per cent of global primary energy demand for the foreseeable future. This paper considers the principal environmental impacts associated with fossil energy use and describes approaches to minimise them. Technologies are now available to reduce significantly pollutant emissions from fossil fuel use. Emerging technologies offer higher conversion efficiencies to reduce still further specific emissions per unit of energy output. It is essential, particularly in those areas of rapid growth in energy use, that best practice and technology are deployed. Technology transfer and training will help to achieve this and enable fossil energy use to be fully compatible with increasingly stringent environmental requirements. (author) 4 figs., 12 refs

Status of fossil fuel reserves

International Nuclear Information System (INIS)

Laherrere, J.

2005-01-01

Reserves represent the sum of past and future productions up to the end of production. In most countries the reserve data of fields are confidential. Therefore, fossil fuel reserves are badly known because the published data are more political than technical and many countries make a confusion between resources and reserves. The cumulated production of fossil fuels represents only between a third and a fifth of the ultimate reserves. The production peak will take place between 2020 and 2050. In the ultimate reserves, which extrapolate the past, the fossil fuels represent three thirds of the overall energy. This document analyses the uncertainties linked with fossil fuel reserves: reliability of published data, modeling of future production, comparison with other energy sources, energy consumption forecasts, reserves/production ratio, exploitation of non-conventional hydrocarbons (tar sands, extra-heavy oils, bituminous shales, coal gas, gas shales, methane in overpressure aquifers, methane hydrates), technology impacts, prices impact, and reserves growth. (J.S.)

New fossil fuel combustion technologies

International Nuclear Information System (INIS)

Minghetti, E.; Palazzi, G.

1995-01-01

The aim of the present article is to supply general information concerning fossil fuels that represent, today and for the near future, the main energy source of our Planet. New fossil fuel technologies are in continual development with two principal goals: to decrease environmental impact and increase transformation process efficiency. Examples of this efforts are: 1) gas-steam combined cycles integrated with coal gasification plants, or with pressurized-fluidized-bed combustors; 2) new cycles with humid air or coal direct fired turbine, now under development. In the first part of this article the international and national energy situations and trends are shown. After some brief notes on environmental problems and alternative fuels, such as bio masses and municipal wastes, technological aspects, mainly relevant to increase fossil-fueled power plant performances, are examined in greater depth. Finally the research and technological development activities of ENEA (Italian Agency for New Technologies, Energy and Environment) Engineering Branch, in order to improve fossil fuels energy and environmental use are presented

Toward an accurate taxonomic interpretation of Carex fossil fruits (Cyperaceae): a case study in section Phacocystis in the Western Palearctic.

Science.gov (United States)

Jiménez-Mejías, Pedro; Martinetto, Edoardo

2013-08-01

Despite growing interest in the systematics and evolution of the hyperdiverse genus Carex, few studies have focused on its evolution using an absolute time framework. This is partly due to the limited knowledge of the fossil record. However, Carex fruits are not rare in certain sediments. We analyzed carpological features of modern materials from Carex sect. Phacocystis to characterize the fossil record taxonomically. We studied 374 achenes from modern materials (18 extant species), as well as representatives from related groups, to establish the main traits within and among species. We also studied 99 achenes from sediments of living populations to assess their modification process after decay. Additionally, we characterized 145 fossil achenes from 10 different locations (from 4-0.02 mya), whose taxonomic assignment we discuss. Five main characters were identified for establishing morphological groups of species (epidermis morphology, achene-utricle attachment, achene base, style robustness, and pericarp section). Eleven additional characters allowed the discrimination at species level of most of the taxa. Fossil samples were assigned to two extant species and one unknown, possibly extinct species. The analysis of fruit characters allows the distinction of groups, even up to species level. Carpology is revealed as an accurate tool in Carex paleotaxonomy, which could allow the characterization of Carex fossil fruits and assign them to subgeneric or sectional categories, or to certain species. Our conclusions could be crucial for including a temporal framework in the study of the evolution of Carex.

Coniacian sandstones from the North Sudetic Synclinorium revisited: palaeoenvironmental and palaeogeographical reconstructions based on trace fossil analysis and associated body fossils

Science.gov (United States)

Chrząstek, Alina; Wypych, Monika

2018-03-01

The Coniacian quartz sandstones (Żerkowice Member, Rakowice Wielkie Formation) that crop out at quarries near Czaple-Nowa Wieś Grodziska (North Sudetic Synclinorium) contain a low-diversity assemblage of trace fossils: Gyrochorte isp., Ophiomorpha nodosa (Lundgren, 1891), Ophiomorpha isp., Phycodes cf. curvipalmatum (Pollard, 1981), ?Phycodes isp., Planolites cf. beverleyensis (Billings, 1862), Thalassinoides paradoxicus (Woodward, 1830) and ?Thalassinoides isp. Moreover, interesting compound burrow systems, here referred to as Thalassinoides-Phycodes cf. palmatus and ?Thalassinoides-Phycodes, were recognised at the Czaple Quarry. Additionally, ?Gyrochorte isp., Phycodes cf. flabellum (Miller and Dyer, 1878) and ?Treptichnus isp. were encountered at correlative levels in the Rakowice Małe Quarry. Some of these ichnotaxa have not been recorded previously from Coniacian sandstones of the Żerkowice Member. Additionally, in slabs of these sandstones, the gastropod Nerinea bicincta (Bronn, 1836) and the bivalve Lima haidingeri (Zittel, 1866) were found. These interesting finds, in particular the gastropods, were already noted from the study area in the first half of the twentieth century by (Scupin (1912-1913)). Ethologically, the trace fossil assemblage is represented by domichnia or domichnia/fodinichnia (Ophiomorpha, Thalassinoides), fodinichnia (Phycodes) and pascichnia (Gyrochorte, Planolites). The compound burrow systems (Thalassinoides-Phycodes) are interpreted as dwelling/feeding structures. The possible tracemakers are crustaceans (Ophiomorpha, Thalassinoides) or worm-like animals (annelids and other) (Planolites, ?Phycodes, Gyrochorte and ?Treptichnus). The assemblage of trace fossils is characteristic of the Skolithos ichnofacies and Cruziana ichnofacies, typical of shallow-marine settings. Ichnological studies, as well as the presence of accompanying fossils (bivalves, gastropods), confirm the palaeoenvironmental reconstruction of the Żerkowice Member

New records of rotifers (Rotifera: Eurotatoria from Deepor Beel - a Ramsar site of India with an update on its rich rotifer diversity.

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B.K. Sharma

2015-03-01

Full Text Available Plankton samples collected from Deepor Beel (a Ramsar site, during July 2011 to June 2013, revealed 155 species of Rotifera, belonging to 35 genera and 20 families.  Of these, 16 species belonging to eight genera and seven families are new records to the rotifer fauna of this wetland of northeast India.  Our observations raise the total richness of the phylum known till date from this important floodplain lake (beel of the Brahmaputra river basin to 171 species and thus highlight its biodiversity value as one of the globally rich Rotifera habitats.  The updated list is interesting for following meta-analyses of rotifer occurrence in this only well sampled freshwater ecosystem of the Indian sub-region. 

Fossil and non-fossil source contributions to atmospheric carbonaceous aerosols during extreme spring grassland fires in Eastern Europe

Science.gov (United States)

Ulevicius, Vidmantas; Byčenkienė, Steigvilė; Bozzetti, Carlo; Vlachou, Athanasia; Plauškaitė, Kristina; Mordas, Genrik; Dudoitis, Vadimas; Abbaszade, Gülcin; Remeikis, Vidmantas; Garbaras, Andrius; Masalaite, Agne; Blees, Jan; Fröhlich, Roman; Dällenbach, Kaspar R.; Canonaco, Francesco; Slowik, Jay G.; Dommen, Josef; Zimmermann, Ralf; Schnelle-Kreis, Jürgen; Salazar, Gary A.; Agrios, Konstantinos; Szidat, Sönke; El Haddad, Imad; Prévôt, André S. H.

2016-05-01

In early spring the Baltic region is frequently affected by high-pollution events due to biomass burning in that area. Here we present a comprehensive study to investigate the impact of biomass/grass burning (BB) on the evolution and composition of aerosol in Preila, Lithuania, during springtime open fires. Non-refractory submicron particulate matter (NR-PM1) was measured by an Aerodyne aerosol chemical speciation monitor (ACSM) and a source apportionment with the multilinear engine (ME-2) running the positive matrix factorization (PMF) model was applied to the organic aerosol fraction to investigate the impact of biomass/grass burning. Satellite observations over regions of biomass burning activity supported the results and identification of air mass transport to the area of investigation. Sharp increases in biomass burning tracers, such as levoglucosan up to 683 ng m-3 and black carbon (BC) up to 17 µg m-3 were observed during this period. A further separation between fossil and non-fossil primary and secondary contributions was obtained by coupling ACSM PMF results and radiocarbon (14C) measurements of the elemental (EC) and organic (OC) carbon fractions. Non-fossil organic carbon (OCnf) was the dominant fraction of PM1, with the primary (POCnf) and secondary (SOCnf) fractions contributing 26-44 % and 13-23 % to the total carbon (TC), respectively. 5-8 % of the TC had a primary fossil origin (POCf), whereas the contribution of fossil secondary organic carbon (SOCf) was 4-13 %. Non-fossil EC (ECnf) and fossil EC (ECf) ranged from 13-24 and 7-13 %, respectively. Isotope ratios of stable carbon and nitrogen isotopes were used to distinguish aerosol particles associated with solid and liquid fossil fuel burning.

Discovery of fossil lamprey larva from the Lower Cretaceous reveals its three-phased life cycle.

Science.gov (United States)

Chang, Mee-mann; Wu, Feixiang; Miao, Desui; Zhang, Jiangyong

2014-10-28

Lampreys are one of the two surviving jawless vertebrate groups and one of a few vertebrate groups with the best exemplified metamorphosis during their life cycle, which consists of a long-lasting larval stage, a peculiar metamorphosis, and a relatively short adulthood with a markedly different anatomy. Although the fossil records have revealed that many general features of extant lamprey adults were already formed by the Late Devonian (ca. 360 Ma), little is known about the life cycle of the fossil lampreys because of the lack of fossilized lamprey larvae or transformers. Here we report the first to our knowledge discovery of exceptionally preserved premetamorphic and metamorphosing larvae of the fossil lamprey Mesomyzon mengae from the Lower Cretaceous of Inner Mongolia, China. These fossil ammocoetes look surprisingly modern in having an eel-like body with tiny eyes, oral hood and lower lip, anteriorly positioned branchial region, and a continuous dorsal skin fin fold and in sharing a similar feeding habit, as judged from the detritus left in the gut. In contrast, the larger metamorphosing individuals have slightly enlarged eyes relative to large otic capsules, thickened oral hood or pointed snout, and discernable radials but still anteriorly extended branchial area and lack a suctorial oral disk, which characterize the early stages of the metamorphosis of extant lampreys. Our discovery not only documents the larval conditions of fossil lampreys but also indicates the three-phased life cycle in lampreys emerged essentially in their present mode no later than the Early Cretaceous.

Fossil Groups as Cosmological Labs

Science.gov (United States)

D'Onghia, Elena

Optical and X-ray measurements of fossil groups (FGs) suggest that they are old and relaxed systems. If FGs are assembled at higher redshift, there is enough time for intermediate-luminosity galaxies to merge, resulting in the formation of the brightest group galaxy (BGG). We carry out the first, systematic study of a large sample of FGs, the "FOssil Group Origins'' (FOGO) based on an International Time Project at the Roque de los Muchachos Observatory. For ten FOGO FGs we have been awarded time at SUZAKU Telescope to measure the temperature of the hot intragroup gas (IGM). For these systems we plan to evaluate and correlate their X-ray luminosity and X-ray temperature, Lx-Tx, optical luminosity and X-ray temperature, Lopt-Tx, and group velocity dispersion with their X-ray temperature, sigma V-Tx, as compared to the non fossil systems. By combining these observations with state-of-art cosmological hydrodynamical simulations we will open a new window into the study of the IGM and the nature of fossil systems. Our proposed work will be of direct relevance for the understanding and interpretation of data from several NASA science missions. Specifically, the scaling relations obtained from these data combined with our predictions obtained using state-of-the-art hydrodynamical simulation numerical adopting a new hydrodynamical scheme will motivate new proposal on CHANDRA X-ray telescope for fossil groups and clusters. We will additionally create a public Online Planetarium Show. This will be an educational site, containing an interactive program called: "A Voyage to our Universe''. In the show we will provide observed images of fossil groups and similar images and movies obtained from the numerical simulations showing their evolution. The online planetarium show will be a useful reference and an interactive educational tool for both students and the public.

Water-rock interactions in discharge areas of Xiangshan Fossil hydrothermal system

International Nuclear Information System (INIS)

Zhou, Wenbin

1992-01-01

Xiangshan Fossil hydrothermal system is located within a volcanic basin of south-eastern China. The fact that most metal mineralizations were found in the discharge areas of the fossil hydrothermal system shows that the discharge areas were special geochemical fields. This paper discusses some important water-rock interactions in the discharge areas of Xiangshan fossil hydrothermal system. When the fluids circulating in the deep section of the hydrothermal system went upward to the discharge area, the physico-chemical conditions under which the fluids were saturated changed so considerably that the original physico-chemical equilibria were broken. Consequently, the fluids tended to move to new equilibrium by means of regulating their chemical compositions. Temperature and pressures of the fluids could be declined greatly in discharge area; the difference of temperature and pressure are determined to be 100--150 C and 1--2 x 10 7 Pa. As a result, a large amount of CO 2 in solution escaped from the fluids in the discharge area, and UO 2 (CO 3 ) n 2(1-n) , stable in CO 2 -rich solutions, could be decomposed into UUO 2 2+ , which could be easily reduced into pitchblende associated by calcite and hematite. The pH values for the fluids tended to increase with the CO 2 escaping, however, the interactions between the hydrothermal fluids and the wall rocks (dominantly aluminosilicate) served as the buffers for the pH, and regulated the pH value around neutral point. The buffer effect was of great importance to uranium mineralization. In addition, isotope exchangements between the fluids and rocks took place extensively

Fossil and non-fossil sources of organic carbon (OC and elemental carbon (EC in Göteborg, Sweden

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S. Szidat

2009-03-01

Full Text Available Particulate matter was collected at an urban site in Göteborg (Sweden in February/March 2005 and in June/July 2006. Additional samples were collected at a rural site for the winter period. Total carbon (TC concentrations were 2.1–3.6 μg m⁻³, 1.8–1.9 μg m⁻³, and 2.2–3.0 μg m⁻³ for urban/winter, rural/winter, and urban/summer conditions, respectively. Elemental carbon (EC, organic carbon (OC, water-insoluble OC (WINSOC, and water-soluble OC (WSOC were analyzed for ¹⁴C in order to distinguish fossil from non-fossil emissions. As wood burning is the single major source of non-fossil EC, its contribution can be quantified directly. For non-fossil OC, the wood-burning fraction was determined independently by levoglucosan and ¹⁴C analysis and combined using Latin-hypercube sampling (LHS. For the winter period, the relative contribution of EC from wood burning to the total EC was >3 times higher at the rural site compared to the urban site, whereas the absolute concentrations of EC from wood burning were elevated only moderately at the rural compared to the urban site. Thus, the urban site is substantially more influenced by fossil EC emissions. For summer, biogenic emissions dominated OC concentrations most likely due to secondary organic aerosol (SOA formation. During both seasons, a more pronounced fossil signal was observed for Göteborg than has previously been reported for Zurich, Switzerland. Analysis of air mass origin using back trajectories suggests that the fossil impact was larger when local sources dominated, whereas long-range transport caused an enhanced non-fossil signal. In comparison to other European locations, concentrations of levoglucosan and other monosaccharide anhydrides were low for the urban and the rural site in the area of Göteborg during winter.

Environmental costs of fossil fuel energy production

International Nuclear Information System (INIS)

Riva, A.; Trebeschi, C.

1997-01-01

The costs of environmental impacts caused by fossil fuel energy production are external to the energy economy and normally they are not reflected in energy prices. To determine the environmental costs associated with an energy source a detailed analysis of all environmental impacts of the complete energy cycle is required. The economic evaluation of environmental damages is presented caused by atmospheric emissions produced by fossil fuel combustion for different uses. Considering the emission factors of sulphur oxides, nitrogen oxides, dust and carbon dioxide and the economic evaluation of their environmental damages reported in literature, a range of environmental costs associated with different fossil fuels and technologies is presented. A comparison of environmental costs resulting from atmospheric emissions produced by fossil-fuel combustion for energy production shows that natural gas has a significantly higher environmental value than other fossil fuels. (R.P.)

Fossil and non-fossil source contributions to atmospheric carbonaceous aerosols during extreme spring grassland fires in Eastern Europe

Directory of Open Access Journals (Sweden)

V. Ulevicius

2016-05-01

Full Text Available In early spring the Baltic region is frequently affected by high-pollution events due to biomass burning in that area. Here we present a comprehensive study to investigate the impact of biomass/grass burning (BB on the evolution and composition of aerosol in Preila, Lithuania, during springtime open fires. Non-refractory submicron particulate matter (NR-PM1 was measured by an Aerodyne aerosol chemical speciation monitor (ACSM and a source apportionment with the multilinear engine (ME-2 running the positive matrix factorization (PMF model was applied to the organic aerosol fraction to investigate the impact of biomass/grass burning. Satellite observations over regions of biomass burning activity supported the results and identification of air mass transport to the area of investigation. Sharp increases in biomass burning tracers, such as levoglucosan up to 683 ng m−3 and black carbon (BC up to 17 µg m−3 were observed during this period. A further separation between fossil and non-fossil primary and secondary contributions was obtained by coupling ACSM PMF results and radiocarbon (14C measurements of the elemental (EC and organic (OC carbon fractions. Non-fossil organic carbon (OCnf was the dominant fraction of PM1, with the primary (POCnf and secondary (SOCnf fractions contributing 26–44 % and 13–23 % to the total carbon (TC, respectively. 5–8 % of the TC had a primary fossil origin (POCf, whereas the contribution of fossil secondary organic carbon (SOCf was 4–13 %. Non-fossil EC (ECnf and fossil EC (ECf ranged from 13–24 and 7–13 %, respectively. Isotope ratios of stable carbon and nitrogen isotopes were used to distinguish aerosol particles associated with solid and liquid fossil fuel burning.

Traversing the mountaintop: world fossil fuel production to 2050.

Science.gov (United States)

Nehring, Richard

2009-10-27

During the past century, fossil fuels--petroleum liquids, natural gas and coal--were the dominant source of world energy production. From 1950 to 2005, fossil fuels provided 85-93% of all energy production. All fossil fuels grew substantially during this period, their combined growth exceeding the increase in world population. This growth, however, was irregular, providing for rapidly growing per capita production from 1950 to 1980, stable per capita production from 1980 to 2000 and rising per capita production again after 2000. During the past half century, growth in fossil fuel production was essentially limited by energy demand. During the next half century, fossil fuel production will be limited primarily by the amount and characteristics of remaining fossil fuel resources. Three possible scenarios--low, medium and high--are developed for the production of each of the fossil fuels to 2050. These scenarios differ primarily by the amount of ultimate resources estimated for each fossil fuel. Total fossil fuel production will continue to grow, but only slowly for the next 15-30 years. The subsequent peak plateau will last for 10-15 years. These production peaks are robust; none of the fossil fuels, even with highly optimistic resource estimates, is projected to keep growing beyond 2050. World fossil fuel production per capita will thus begin an irreversible decline between 2020 and 2030.

Fossil fuel support mechanisms in Finland

Energy Technology Data Exchange (ETDEWEB)

Lampinen, Ari

2013-10-15

Fossil fuel subsidies and other state support for fossil fuels are forbidden by the Kyoto Protocol and other international treaties. However, they are still commonly used. This publication presents and analyses diverse state support mechanisms for fossil fuels in Finland in 2003-2010. Total of 38 support mechanisms are covered in quantitative analysis and some other mechanisms are mentioned qualitatively only. For some mechanisms the study includes a longer historical perspective. This is the case for tax subsidies for crude oil based traffic fuels that have been maintained in Finland since 1965.

Fossil power plant automation

International Nuclear Information System (INIS)

Divakaruni, S.M.; Touchton, G.

1991-01-01

This paper elaborates on issues facing the utilities industry and seeks to address how new computer-based control and automation technologies resulting from recent microprocessor evolution, can improve fossil plant operations and maintenance. This in turn can assist utilities to emerge stronger from the challenges ahead. Many presentations at the first ISA/EPRI co-sponsored conference are targeted towards improving the use of computer and control systems in the fossil and nuclear power plants and we believe this to be the right forum to share our ideas

Direct dating of fossils by the helium-uranium method

International Nuclear Information System (INIS)

Schaeffer, O.A.

1967-01-01

The He-U method has been found to be applicable to the dating of fossil carbonates. This method furnishes a new dating technique particularly applicable to the Pleistocene and the Tertiary periods, especially the Late Tertiary, for which other methods of age dating either fail or are difficult to correlate with the fossil record. The method has been checked for possible losses of helium and uranium from or to the surroundings. It has been found that, while a calcite lattice does not appear to retain helium, if the lattice is aragonite there is good evidence that helium leakage is not a problem. This is true at least for times up to 20 m. y. For corals where the uranium is apparently uniformly distributed within the lattice as a trace element, the uranium does not exchange or undergo concentration changes. As a result aragonite corals yield reliable He-U ages. On the other hand, the uranium in mollusc fossils is apparently mainly in the grain boundaries and is not always a tight system as far as uranium exchange or concentration changes are concerned. To obtain a reliable age for a mollusc one needs additional evidence to ensure lack of changes in uranium concentration. If the measurement of U and He is combined with 238 U, 234 U and 230 Th determinations, it appears that many mollusc shells will also be datable by the method. The resulting evidence for secular equilibrium in the 238 U chain is good evidence for a closed system as far as U concentration changes are concerned. (author)

Stable isotopic analysis of fossil chironomids as an approach to environmental reconstruction: state of development and future challenges

Directory of Open Access Journals (Sweden)

Oliver Heiri

2012-10-01

Full Text Available Remains of chironomid larvae, especially their strongly sclerotized head capsules, can be found abundantly and well preserved in most lake sediment records. These remains mainly consist of chitin and proteins and, since their chemical composition does not seem to be strongly affected by decompositional processes, they can be used to develop palaeoenvironmental reconstructions based on their stable isotopic composition. Here we review available stable isotope studies based on fossil chironomids and indicate future research necessary to further develop this still relatively new research approach. Efforts to produce stable isotope records based on fossil chironomids have mainly examined the elements H, N, C, and O. They have focussed on (1 developing the methodology for preparing samples for isotopic analysis, (2 laboratory studies cultivating chironomid larvae under controlled conditions to determine the factors affecting their stable isotopic composition, (3 ecosystem-scale studies relating stable isotopic measurements of fossil chironomid assemblages to environmental conditions, and (4 developing first down-core records describing past changes in the stable isotopic composition of chironomid assemblages. These studies have shown that chemical sample pretreatment may affect the isotopic composition for some elements. Laboratory runs suggest that the diet of the larvae influences their stable isotopic composition for H, N, C and O, whereas stable isotopes in the ambient water also strongly influence their oxygen and to a lesser extent hydrogen isotopic composition. These experiments also indicate only minor offsets between the nitrogen and carbon isotopic composition of chironomid soft tissue and the fossilizing head capsules, whereas for hydrogen and oxygen this offset remains to be explored. Though few datasets have been published, the available ecosystem studies and developed down-core sediment records indicate that stable isotopes in

First fossil occurrence of a filefish (Tetraodontiformes; Monacanthidae) in Asia, from the Middle Miocene in Nagano Prefecture, central Japan.

Science.gov (United States)

Miyajima, Yusuke; Koike, Hakuichi; Matsuoka, Hiroshige

2014-04-10

A new fossil filefish, Aluterus shigensis sp. nov., with a close resemblance to the extant Aluterus scriptus (Osbeck), is described from the Middle Miocene Bessho Formation in Nagano Prefecture, central Japan. It is characterized by: 21 total vertebrae; very slender and long first dorsal spine with tiny anterior barbs; thin and lancet-shaped basal pterygiophore of the spiny dorsal fin, with its ventral margin separated from the skull; proximal tip of moderately slender first pterygiophore of the soft dorsal fin not reaching far ventrally; soft dorsal-fin base longer than anal-fin base; caudal peduncle having nearly equal depth and length; and tiny, fine scales with slender, straight spinules. The occurrence of this fossil filefish from the Bessho Formation is consistent with the influence of warm water currents suggested by other fossils, but it is inconsistent with the deep-water sedimentary environment of this Formation. This is the first fossil occurrence of a filefish in Asia; previously described fossil filefishes are known from the Pliocene and Pleistocene of Italy, the Pliocene of Greece, and the Miocene and Pliocene of North America. These fossil records suggest that the genus Aluterus had already been derived and was widely distributed during the Middle Miocene with taxa closely resembling Recent species.

Paleoclimate Reconstruction during the 17th to 18th Century Using Fossil Coral Tsunami Boulders from Ishigaki Island, the Ryukyus, Japan

Science.gov (United States)

Tsuzuki, K.; Yokoyama, Y.; Seki, A.; Kawakubo, Y.; Araoka, D.; Suzuki, A.

2014-12-01

Little Ice Age (LIA) which lasted during approximately 1450 to 1850 (e.g. Grove, 1988) is known as naturally occurring climate fluctuation, so knowing LIA in detail is necessary to improve climate models. Instrumental records can only extend back to about 100 years in many areas, thus paleoclimate records are reconstructed using proxies in tree rings, sediments and so force. However there are differences in reconstructed timings and magnitudes of LIA occurred in each area (Overpack et al., 1997), and most of the records are based mainly on terrestrial proxies such as tree ring records, whereas only limited numbers of marine records are available (Mann et al., 2008). Coral skeletal climatology is a useful tool to reconstruct marine paleoclimate records in tropics and subtropics. Hermatypic corals, Porites spp. have aragonite skeletons and they have annual bands, which are suitable to reconstruct high-resolution paleoclimate in seasonal scale by measuring chemical compositions. Skeletal Sr/Ca ratio in Porites spp. has been widely used as a reliable proxy of SST (Sea Surface Temperature). However, corals grow for approximately several decades to 200 years, hence it is difficult to reconstruct LIA paleoclimate using living corals. Cobb et al. (2003) used fossil corals casted on shore by storms to reconstruct millennial scale paleoclimate. There are fossil coral boulders in the eastern coast of Ishigaki Island, Ryukyus, Japan. These fossil coral boulders were casted on shore by paleo Tsunami events, thus they are called "Tsunami boulders" (Araoka et al., 2010). Fossil corals used by Cobb et al. have 30-90-year records while some large Tsunami boulders have multi-centennial continuous records. In this study, we reconstruct paleo SST using the Tsunami boulder from Ishigaki Island. The boulder has 185 years of annual banding. U-series dating shows the boulder was moved on shore at Meiwa earthquake in 1771. We measure Sr/Ca ratio using LA-HR-ICPMS (Laser Ablation High

Geographic range size and determinants of avian species richness

DEFF Research Database (Denmark)

Jetz, Walter; Rahbek, Carsten

2002-01-01

Geographic patterns in species richness are mainly based on wide-ranging species because their larger number of distribution records has a disproportionate contribution to the species richness counts. Here we demonstrate how this effect strongly influences our understanding of what determines spe...

Progress of fossil fuel science

Energy Technology Data Exchange (ETDEWEB)

Demirbas, M.F.

2007-07-01

Coal is the most abundant and widely distributed fossil fuel. More than 45% of the world's electricity is generated from coal, and it is the major fuel for generating electricity worldwide. The known coal reserves in the world are enough for more than 215 years of consumption, while the known oil reserves are only about 39 times of the world's consumption and the known natural gas reserves are about 63 times of the world's consumption level in 1998. In recent years, there have been effective scientific investigations on Turkish fossil fuels, which are considerable focused on coal resources. Coal is a major fossil fuel source for Turkey. Turkish coal consumption has been stable over the past decade and currently accounts for about 24% of the country's total energy consumption. Lignite coal has had the biggest share in total fossil fuel production, at 43%, in Turkey. Turkish researchers may investigate ten broad pathways of coal species upgrading, such as desulfurization and oxydesulfurization, pyrolysis and hydropyrolysis, liquefaction and hydroliquefaction, extraction and supercritical fluid extraction, gasification, oxidation, briquetting, flotation, and structure identification.

Fossil energy and food security

International Nuclear Information System (INIS)

Folke, G.

2001-01-01

To fulfil the basic goal of delivering food for the tables of the citizens, modern Western agriculture is extremely dependent on supporting material flows, infrastructure, and fossil energy. According to several observers, fossil fuel production is about to peak, i.e., oil extraction is no longer capable of keeping pace with the increasing demand. This situation may trigger an unprecedented increase in fossil energy prices, which may make the current highly energy dependent food production-distribution system highly vulnerable. The paper starts with a survey of this vulnerability. Also, the supply of phosphorus, a key factor in agriculture, may be at stake under such circumstances. The paper analyses this situation and discusses settlement structures integrated with agriculture that might increase food security by reducing energy demands. In the proposed ideal societal structure, agriculture is integrated with settlements and most of the food needed by the population is produced locally, and the nutrients for food production are recycled from households and animals by means of biological processes demanding considerably less mechanical investment and fossil support energy than the conventional type of agriculture. The vulnerability of this structure would be considerably lower, than that of the current system. (author)

Molecular fossils of prokaryotes in ancient authigenic minerals: archives of microbial activity in reefs and mounds?

Science.gov (United States)

Heindel, Katrin; Birgel, Daniel; Richoz, Sylvain; Westphal, Hildegard; Peckmann, Jörn

2016-04-01

Molecular fossils (lipid biomarkers) are commonly used as proxies in organic-rich sediments of various sources, including eukaryotes and prokaryotes. Usually, molecular fossils of organisms transferred from the water column to the sediment are studied to monitor environmental changes (e.g., temperature, pH). Apart from these 'allochthonous' molecular fossils, prokaryotes are active in sediments and mats on the seafloor and leave behind 'autochthonous' molecular fossils in situ. In contrast to many phototrophic organisms, most benthic sedimentary prokaryotes are obtaining their energy from oxidation or reduction of organic or inorganic substrates. A peculiarity of some of the sediment-thriving prokaryotes is their ability to trigger in situ mineral precipitation, often but not only due to metabolic activity, resulting in authigenic rocks (microbialites). During that process, prokaryotes are rapidly entombed in the mineral matrix, where the molecular fossils are protected from early (bio)degradation. In contrast to other organic compounds (DNA, proteins etc.), molecular fossils can be preserved over very long time periods (millions of years). Thus, molecular fossils in authigenic mineral phases are perfectly suitable to trace microbial activity back in time. Among the best examples of molecular fossils, which are preserved in authigenic rocks are various microbialites, forming e.g. in phototrophic microbial mats and at cold seeps. Microbialite formation is reported throughout earth history. We here will focus on reefal microbialites form the Early Triassic and the Holocene. After the End-Permian mass extinction, microbialites covered wide areas on the ocean margins. In microbialites from the Griesbachian in Iran and Turkey (both Neotethys), molecular fossils of cyanobacteria, archaea, anoxygenic phototrophs, and sulphate-reducing bacteria indicate the presence of layered microbial mats on the seafloor, in which carbonate precipitation was induced. In association with

Hawaii energy strategy project 2: Fossil energy review. Task 1: World and regional fossil energy dynamics

Energy Technology Data Exchange (ETDEWEB)

Breazeale, K. [ed.; Isaak, D.T.; Yamaguchi, N.; Fridley, D.; Johnson, C.; Long, S.

1993-12-01

This report in the Hawaii Energy Strategy Project examines world and regional fossil energy dynamics. The topics of the report include fossil energy characteristics, the world oil industry including reserves, production, consumption, exporters, importers, refining, products and their uses, history and trends in the global oil market and the Asia-Pacific market; world gas industry including reserves, production, consumption, exporters, importers, processing, gas-based products, international gas market and the emerging Asia-Pacific gas market; the world coal industry including reserves, classification and quality, utilization, transportation, pricing, world coal market, Asia-Pacific coal outlook, trends in Europe and the Americas; and environmental trends affecting fossil fuels. 132 figs., 46 tabs.

Early evolution and historical biogeography of fishflies (Megaloptera: Chauliodinae: implications from a phylogeny combining fossil and extant taxa.

Directory of Open Access Journals (Sweden)

Xingyue Liu

Full Text Available Fishflies (Corydalidae: Chauliodinae are one of the main groups of the basal holometabolous insect order Megaloptera, with ca. 130 species distributed worldwide. A number of genera from the Southern Hemisphere show remarkably disjunctive distributions and are considered to be the austral remnants or "living fossils" of Gondwana. Hitherto, the evolutionary history of fishflies remains largely unexplored due to limited fossil record and incomplete knowledge of phylogenetic relationships. Here we describe two significant fossil species of fishflies, namely Eochauliodes striolatus gen. et sp. nov. and Jurochauliodes ponomarenkoi Wang & Zhang, 2010 (original designation for fossil larvae only, from the Middle Jurassic of Inner Mongolia, China. These fossils represent the earliest fishfly adults. Furthermore, we reconstruct the first phylogenetic hypothesis including all fossil and extant genera worldwide. Three main clades within Chauliodinae are recognized, i.e. the Dysmicohermes clade, the Protochauliodes clade, and the Archichauliodes clade. The phylogenetic and dispersal-vicariance (DIVA analyses suggest Pangaean origin and global distribution of fishflies before the Middle Jurassic. The generic diversification of fishflies might have happened before the initial split of Pangaea, while some Gondwanan-originated clades were likely to be affected by the sequential breakup of Pangaea. The modern fauna of Asian fishflies were probably derived from their Gondwanan ancestor but not the direct descendents of the Mesozoic genera in Asia.

Early evolution and historical biogeography of fishflies (Megaloptera: Chauliodinae): implications from a phylogeny combining fossil and extant taxa.

Science.gov (United States)

Liu, Xingyue; Wang, Yongjie; Shih, Chungkun; Ren, Dong; Yang, Ding

2012-01-01

Fishflies (Corydalidae: Chauliodinae) are one of the main groups of the basal holometabolous insect order Megaloptera, with ca. 130 species distributed worldwide. A number of genera from the Southern Hemisphere show remarkably disjunctive distributions and are considered to be the austral remnants or "living fossils" of Gondwana. Hitherto, the evolutionary history of fishflies remains largely unexplored due to limited fossil record and incomplete knowledge of phylogenetic relationships. Here we describe two significant fossil species of fishflies, namely Eochauliodes striolatus gen. et sp. nov. and Jurochauliodes ponomarenkoi Wang & Zhang, 2010 (original designation for fossil larvae only), from the Middle Jurassic of Inner Mongolia, China. These fossils represent the earliest fishfly adults. Furthermore, we reconstruct the first phylogenetic hypothesis including all fossil and extant genera worldwide. Three main clades within Chauliodinae are recognized, i.e. the Dysmicohermes clade, the Protochauliodes clade, and the Archichauliodes clade. The phylogenetic and dispersal-vicariance (DIVA) analyses suggest Pangaean origin and global distribution of fishflies before the Middle Jurassic. The generic diversification of fishflies might have happened before the initial split of Pangaea, while some Gondwanan-originated clades were likely to be affected by the sequential breakup of Pangaea. The modern fauna of Asian fishflies were probably derived from their Gondwanan ancestor but not the direct descendents of the Mesozoic genera in Asia.

The GB/3D Type Fossils Online Web Portal

Science.gov (United States)

McCormick, T.; Howe, M. P.

2013-12-01

fossils which can be used in education and public outreach. The audience for the web portal includes both professional paleontologists and the general public. The professional paleontologist can use the portal to discover the whereabouts of the type material for a taxon they are studying, and can use the pictures and 3d models to assess the completeness and preservation quality of the material. This may reduce or negate the need to send specimens (which are often fragile and always irreplaceable) to researchers through the post, or for researchers to make possibly long, expensive and environmentally damaging journeys to visit far-off collections. We hope that the pictures and 3d models will help to stimulate public interest in paleontology and natural history. The ability to digitally image and scan specimens in 3d enables institutions to have an archive record in case specimens are lost or destroyed by accident or warfare. Recent events in Cairo and Baghdad remind us that museum collections are vulnerable to civil and military strife.

Supply of fossil heating and motor fuels

International Nuclear Information System (INIS)

Kaegi, W.; Siegrist, S.; Schaefli, M.; Eichenberger, U.

2003-01-01

This comprehensive study made for the Swiss Federal Office of Energy (SFOE) within the framework of the Energy Economics Fundamentals research programme examines if it can be guaranteed that Swiss industry can be supplied with fossil fuels for heating and transport purposes over the next few decades. The results of a comprehensive survey of literature on the subject are presented, with a major focus being placed on oil. The study examines both pessimistic and optimistic views and also presents an overview of fossil energy carriers and the possibilities of substituting them. Scenarios and prognoses on the availability of fossil fuels and their reserves for the future are presented. Also, new technologies for exploration and the extraction of fossil fuels are discussed, as are international interdependencies that influence supply. Market and price scenarios are presented that take account of a possible increasing scarcity of fossil fuels. The implications for industry and investment planning are examined

Influence of microbial biofilms on the preservation of primary soft tissue in fossil and extant archosaurs.

Directory of Open Access Journals (Sweden)

Joseph E Peterson

Full Text Available BACKGROUND: Mineralized and permineralized bone is the most common form of fossilization in the vertebrate record. Preservation of gross soft tissues is extremely rare, but recent studies have suggested that primary soft tissues and biomolecules are more commonly preserved within preserved bones than had been presumed. Some of these claims have been challenged, with presentation of evidence suggesting that some of the structures are microbial artifacts, not primary soft tissues. The identification of biomolecules in fossil vertebrate extracts from a specimen of Brachylophosaurus canadensis has shown the interpretation of preserved organic remains as microbial biofilm to be highly unlikely. These discussions also propose a variety of potential mechanisms that would permit the preservation of soft-tissues in vertebrate fossils over geologic time. METHODOLOGY/PRINCIPAL FINDINGS: This study experimentally examines the role of microbial biofilms in soft-tissue preservation in vertebrate fossils by quantitatively establishing the growth and morphology of biofilms on extant archosaur bone. These results are microscopically and morphologically compared with soft-tissue extracts from vertebrate fossils from the Hell Creek Formation of southeastern Montana (Latest Maastrichtian in order to investigate the potential role of microbial biofilms on the preservation of fossil bone and bound organic matter in a variety of taphonomic settings. Based on these analyses, we highlight a mechanism whereby this bound organic matter may be preserved. CONCLUSIONS/SIGNIFICANCE: Results of the study indicate that the crystallization of microbial biofilms on decomposing organic matter within vertebrate bone in early taphonomic stages may contribute to the preservation of primary soft tissues deeper in the bone structure.

Fossilized intact polar lipids of photosynthetic organisms in ancient subsurface sediments

Science.gov (United States)

Bauersachs, T.; Schouten, S.; Hopmans, E. C.; Sinninghe Damsté, J. S.

2009-12-01

(47 Ma) and the Eocene Green-River Formation (ca. 50 Ma). The presence of IPLs such as HGs in these ancient sediments is remarkable, given the assumed lability of IPLs with glycosidic or phosphoric head groups. Our data, however, show that HGs with glycosidically bound head groups, unambiguously derived from photoautotrophic organisms living in the photic zone of the water column, can fossilize and be well preserved in the sedimentary record. The presence of HGs in fossil sediments, thus, raises the question whether certain IPLs, especially those with glycosidic head groups, may be more recalcitrant than previously thought and can constitute a significant fossil component of the so-called IPL fraction. This has important consequences (1) for the use of IPLs as a proxy of living prokaryotic biomass and (2) for the conclusion that Archaea are the main standing stock of prokaryotes in the deep-biosphere.

Management of fossil natural resources: the impossible challenge?

International Nuclear Information System (INIS)

Loubens, Audrey

2013-10-01

A set of articles addresses various issues related to fossil energies and resources. A first set addresses the general context of fossil resources: the forced wedding between fossil energies and the environment (discussion of an annual report by the IEA on coal reserves), the availability of fossil fuels (discussion about the high share of fossil fuel in an always more renewable world). A second set addresses how to transform resources into reserves: discussion of the annual IEA report on conventional oil and gas reserves, on unconventional oil and gas reserves, and on coal reserves. The next set is a prospective one, and addresses the question of a scenario by 2040: the extremely high tension between fossil resources and geopolitical reality, and the question of the possibility of a world energy transition (discussions of the World Energy Outlook published by the IEA). Other issues are addressed by the last set of articles: the abundance of fossil energies obscures the potential of renewable energies, the evolution of the chemical industry towards alternative solutions in order to limit the use of hydrocarbons, and the territorial claims by Russia in the Arctic region

Combining phylogenomics and fossils in higher-level squamate reptile phylogeny: molecular data change the placement of fossil taxa.

Science.gov (United States)

Wiens, John J; Kuczynski, Caitlin A; Townsend, Ted; Reeder, Tod W; Mulcahy, Daniel G; Sites, Jack W

2010-12-01

Molecular data offer great potential to resolve the phylogeny of living taxa but can molecular data improve our understanding of relationships of fossil taxa? Simulations suggest that this is possible, but few empirical examples have demonstrated the ability of molecular data to change the placement of fossil taxa. We offer such an example here. We analyze the placement of snakes among squamate reptiles, combining published morphological data (363 characters) and new DNA sequence data (15,794 characters, 22 nuclear loci) for 45 living and 19 fossil taxa. We find several intriguing results. First, some fossil taxa undergo major changes in their phylogenetic position when molecular data are added. Second, most fossil taxa are placed with strong support in the expected clades by the combined data Bayesian analyses, despite each having >98% missing cells and despite recent suggestions that extensive missing data are problematic for Bayesian phylogenetics. Third, morphological data can change the placement of living taxa in combined analyses, even when there is an overwhelming majority of molecular characters. Finally, we find strong but apparently misleading signal in the morphological data, seemingly associated with a burrowing lifestyle in snakes, amphisbaenians, and dibamids. Overall, our results suggest promise for an integrated and comprehensive Tree of Life by combining molecular and morphological data for living and fossil taxa.

Molecules, morphometrics and new fossils provide an integrated view of the evolutionary history of Rhinopomatidae (Mammalia: Chiroptera).

Science.gov (United States)

Hulva, Pavel; Horácek, Ivan; Benda, Petr

2007-09-14

The Rhinopomatidae, traditionally considered to be one of the most ancient chiropteran clades, remains one of the least known groups of Rhinolophoidea. No relevant fossil record is available for this family. Whereas there have been extensive radiations in related families Rhinolophidae and Hipposideridae, there are only a few species in the Rhinopomatidae and their phylogenetic relationship and status are not fully understood. Here we present (a) a phylogenetic analysis based on a partial cytochrome b sequence, (b) new fossils from the Upper Miocene site Elaiochoria 2 (Chalkidiki, Greece), which represents the first appearance datum of the family based on the fossil record, and (c) discussion of the phylogeographic patterns in both molecular and morphological traits. We found deep divergences in the Rhinopoma hardwickii lineage, suggesting that the allopatric populations in (i) Iran and (ii) North Africa and the Middle East should have separate species status. The latter species (R. cystops) exhibits a shallow pattern of isolation by distance (separating the Middle East and the African populations) that contrasts with the pattern of geographic variation in the morphometrical traits. A deep genetic gap was also found in Rhinopoma muscatellum (Iran vs. Yemen). We found only minute genetic distance between R. microphyllum from the Levant and India, which fails to support the sub/species distinctness of the Indian form (R. microphyllum kinneari). The mtDNA survey provided phylogenetic tree of the family Rhinopomatidae for the first time and revealed an unexpected diversification of the group both within R. hardwickii and R. muscatellum morphospecies. The paleobiogeographic scenario compiled in respect to molecular clock data suggests that the family originated in the region south of the Eocene Western Tethyan seaway or in India, and extended its range during the Early Miocene. The fossil record suggests a Miocene spread into the Mediterranean region, followed by a post

Molecules, morphometrics and new fossils provide an integrated view of the evolutionary history of Rhinopomatidae (Mammalia: Chiroptera

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Benda Petr

2007-09-01

Full Text Available Abstract Background The Rhinopomatidae, traditionally considered to be one of the most ancient chiropteran clades, remains one of the least known groups of Rhinolophoidea. No relevant fossil record is available for this family. Whereas there have been extensive radiations in related families Rhinolophidae and Hipposideridae, there are only a few species in the Rhinopomatidae and their phylogenetic relationship and status are not fully understood. Results Here we present (a a phylogenetic analysis based on a partial cytochrome b sequence, (b new fossils from the Upper Miocene site Elaiochoria 2 (Chalkidiki, Greece, which represents the first appearance datum of the family based on the fossil record, and (c discussion of the phylogeographic patterns in both molecular and morphological traits. We found deep divergences in the Rhinopoma hardwickii lineage, suggesting that the allopatric populations in (i Iran and (ii North Africa and the Middle East should have separate species status. The latter species (R. cystops exhibits a shallow pattern of isolation by distance (separating the Middle East and the African populations that contrasts with the pattern of geographic variation in the morphometrical traits. A deep genetic gap was also found in Rhinopoma muscatellum (Iran vs. Yemen. We found only minute genetic distance between R. microphyllum from the Levant and India, which fails to support the sub/species distinctness of the Indian form (R. microphyllum kinneari. Conclusion The mtDNA survey provided phylogenetic tree of the family Rhinopomatidae for the first time and revealed an unexpected diversification of the group both within R. hardwickii and R. muscatellum morphospecies. The paleobiogeographic scenario compiled in respect to molecular clock data suggests that the family originated in the region south of the Eocene Western Tethyan seaway or in India, and extended its range during the Early Miocene. The fossil record suggests a Miocene spread

Fossil fuel usage and the environment

International Nuclear Information System (INIS)

Klass, D.L.

1991-01-01

The Greenhouse Effect and global warming, ozone formation in the troposphere, ozone destruction in the stratosphere, and acid rain are important environmental issues. The relationship of fossil fuel usage to some of these issues is discussed. Data on fossil fuel consumption and the sources and sinks of carbon dioxide, carbon monoxide, methane, nitrogen and sulfur oxides, and ozone indicate that natural gas provides lower emissions of carbon dioxide, carbon monoxide, and nitrogen and sulfur oxides than other fossil fuels. Global emissions of methane from the gas industry are significantly less than those from other anthropogenic activities and natural sources, and methane plays an important role along with carbon monoxide and nitric oxide in tropospheric ozone formation. Reductions in any or all of these air pollutants would reduce ozone in the lower atmosphere. Several remedial measures have been or are being implemented in certain countries to reduce fossil fuel emissions. These include removal of emissions from the atmosphere by new biomass growth, fuel substitution by use of cleaner burning fuels for stationary and mobile sources, and fossil fuel combustion at higher efficiencies. It is unlikely that concerted environmental action by all governments of the world will occur soon, but much progress has been made to achieve clean air

The extinct river shark Glyphis pagoda from the Miocene of Myanmar and a review of the fossil record of the genus Glyphis (Carcharhiniformes: Carcharhinidae).

Science.gov (United States)

Shimada, Kenshu; Egi, Naoko; Tsubamoto, Takehisa; Maung-Maung, Maung-Maung; Thaung-Htike, Thaung-Htike; Zin-Maung-Maung-Thein, Zin-Maung-Maung-Thein; Nishioka, Yuichiro; Sonoda, Teppei; Takai, Masanaru

2016-09-05

We redescribe an extinct river shark, Glyphis pagoda (Noetling), on the basis of 20 teeth newly collected from three different Miocene localities in Myanmar. One locality is a nearshore marine deposit (Obogon Formation) whereas the other two localities represent terrestrial freshwater deposits (Irrawaddy sediments), suggesting that G. pagoda from the Irrawaddy sediments was capable of tolerating low salinity like the extant Glyphis. Glyphis pagoda likely reached up to at least 185 cm in total body length and was probably piscivorous. The fossil species occurs in rocks of Myanmar and eastern and western India and stratigraphically ranges at least from the Lower Miocene (Aquitanian) to the lower Upper Miocene (mid-Tortonian). It has been classified under at least eight other genera to date, along with numerous taxonomic synonyms largely stemming from the lack of understanding of the heterodonty in extant Glyphis in the original description. Our literature review suggests that known Miocene shark faunas, particularly those in India, are manifested with unreliable taxonomic identifications and outdated classifications that warrant the need for a comprehensive taxonomic review in order to evaluate the evolutionary history and diversity pattern of Miocene shark faunas. The genus Glyphis has a roughly 23-million-year-long history, and its success may be related to the evolution of its low salinity tolerance. While extant Glyphis spp. are considered to be particularly vulnerable to habitat degradation and overfishing, the fossil record of G. pagoda provides renewed perspective on the natural history of the genus that can be taken into further consideration for conservation biology of the extant forms.

Characterization of Pustular Mats and Related Rivularia-Rich Laminations in Oncoids From the Laguna Negra Lake (Argentina

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Estela C. Mlewski

2018-05-01

Full Text Available Stromatolites are organo-sedimentary structures that represent some of the oldest records of the early biosphere on Earth. Cyanobacteria are considered as a main component of the microbial mats that are supposed to produce stromatolite-like structures. Understanding the role of cyanobacteria and associated microorganisms on the mineralization processes is critical to better understand what can be preserved in the laminated structure of stromatolites. Laguna Negra (Catamarca, Argentina, a high-altitude hypersaline lake where stromatolites are currently formed, is considered as an analog environment of early Earth. This study aimed at characterizing carbonate precipitation within microbial mats and associated oncoids in Laguna Negra. In particular, we focused on carbonated black pustular mats. By combining Confocal Laser Scanning Microscopy, Scanning Electron Microscopy, Laser Microdissection and Whole Genome Amplification, Cloning and Sanger sequencing, and Focused Ion Beam milling for Transmission Electron Microscopy, we showed that carbonate precipitation did not directly initiate on the sheaths of cyanobacterial Rivularia, which dominate in the mat. It occurred via organo-mineralization processes within a large EPS matrix excreted by the diverse microbial consortium associated with Rivularia where diatoms and anoxygenic phototrophic bacteria were particularly abundant. By structuring a large microbial consortium, Rivularia should then favor the formation of organic-rich laminations of carbonates that can be preserved in stromatolites. By using Fourier Transform Infrared spectroscopy and Synchrotron-based deep UV fluorescence imaging, we compared laminations rich in structures resembling Rivularia to putatively chemically-precipitated laminations in oncoids associated with the mats. We showed that they presented a different mineralogy jointly with a higher content in organic remnants, hence providing some criteria of biogenicity to be searched

Using Strong Gravitational Lensing to Identify Fossil Group Progenitors

Science.gov (United States)

Johnson, Lucas E.; Irwin, Jimmy A.; White, Raymond E., III; Wong, Ka-Wah; Maksym, W. Peter; Dupke, Renato A.; Miller, Eric D.; Carrasco, Eleazar R.

2018-04-01

Fossil galaxy systems are classically thought to be the end result of galaxy group/cluster evolution, as galaxies experiencing dynamical friction sink to the center of the group potential and merge into a single, giant elliptical that dominates the rest of the members in both mass and luminosity. Most fossil systems discovered lie within z fossil criteria within the look forward time. Since strong gravitational lensing preferentially selects groups merging along the line of sight, or systems with a high mass concentration like fossil systems, we searched the CASSOWARY survey of strong-lensing events with the goal of determining whether lensing systems have any predisposition to being fossil systems or progenitors. We find that ∼13% of lensing groups are identified as traditional fossils while only ∼3% of nonlensing control groups are. We also find that ∼23% of lensing systems are traditional fossil progenitors compared to ∼17% for the control sample. Our findings show that strong-lensing systems are more likely to be fossil/pre-fossil systems than comparable nonlensing systems. Cumulative galaxy luminosity functions of the lensing and nonlensing groups also indicate a possible, fundamental difference between strong-lensing and nonlensing systems’ galaxy populations, with lensing systems housing a greater number of bright galaxies even in the outskirts of groups.

Developments in fossil fuel electricity generation

International Nuclear Information System (INIS)

Williams, A.; Argiri, M.

1993-01-01

A major part of the world's electricity is generated by the combustion of fossil fuels, and there is a significant environmental impact due to the production of fossil fuels and their combustion. Coal is responsible for 63% of the electricity generated from fossil fuels; natural gas accounts for about 20% and fuel oils for 17%. Because of developments in supply and improvements in generating efficiencies there is apparently a considerable shift towards a greater use of natural gas, and by the year 2000 it could provide 25% of the world electricity output. At the same time the amount of fuel oil burned will have decreased. The means to minimize the environmental impact of the use of fossil fuels, particularly coal, in electricity production are considered, together with the methods of emission control. Cleaner coal technologies, which include fluidized bed combustion and an integrated gasification combined cycle (IGCC), can reduce the emissions of NO x , SO 2 and CO 2 . (author)

17. Annotations to the map of the more important fossil localities in the Netherlands East Indies

NARCIS (Netherlands)

Krijnen, W.F.

1931-01-01

For the compilation of the map of fossil localities I have followed the example of Dr. A. Tobler (bibl. 194), arranging the localities according to age. The localities from which more than one formation has been recorded, are numbered for the oldest formation found. In the list these numbers are

Looking for Fossil Bacteria in Martian Materials

Science.gov (United States)

Westall, F.; Walsh, M. M.; Mckay, D. D.; Wentworth, S.; Gibson, E. K.; Steele, A.; Toporski, J.; Lindstrom, D.; Martinez, R.; Allen, C. C.

1999-01-01

The rationale for looking for prokaryote fossils in Martian materials is based on our present understanding of the environmental evolution of that planet in comparison to the history of the terrestrial environments and the development and evolution of life on Earth. On Earth we have clear, albeit indirect, evidence of life in 3.8 b.y.-old rocks from Greenland and the first morphological fossils in 3.3-3.5 b.y.-old cherts from South Africa and Australia. In comparison, Mars, being smaller, probably cooled down after initial aggregation faster than the Earth. Consequently, there could have been liquid water on its surface earlier than on Earth. With a similar exogenous and endogenous input of organics and life-sustaining nutrients as is proposed for the Earth, life could have arisen on that planet, possibly slightly earlier dm it did on Earth. Whereas on Earth liquid water has remained at the surface of the planet since about 4.4 b.y. (with some possible interregnums caused by planet-sterilising impacts before 3.8. b.y. and perhaps a number of periods of a totally frozen Earth, this was not the case with Mars. Although it is not known exactly when surficial water disappeared from the surface, there would have been sufficient time for life to have developed into something similar to the terrestrial prokaryote stage. However, given the earlier environmental deterioration, it is unlikely that it evolved into the eukaryote stage and even evolution of oxygenic photosynthesis may not have been reached. Thus, the impetus of research is on single celled life simnilar to prokaryotes. We are investigating a number of methods of trace element analysis with respect to the Early Archaean microbial fossils. Preliminary neutron activation analysis of carbonaceous layers in the Early Archaean cherts from South Africa and Australia shows some partitioning of elements such as As, Sb, Cr with an especial enrichment of lanthanides in a carbonaceous-rich banded iron sediment . More

OKLO: fossil reactors

International Nuclear Information System (INIS)

Naudet, R.

Events leading up to the discovery during the summer of 1972 of the Oklo fossil reactor in Gabon and its subsequent exploration are reviewed. Results of studies are summarized; future investigations are outlined

Taxing fossil fuels under speculative storage

International Nuclear Information System (INIS)

Tumen, Semih; Unalmis, Deren; Unalmis, Ibrahim; Unsal, D. Filiz

2016-01-01

Long-term environmental consequences of taxing fossil fuel usage have been extensively studied in the literature. However, these taxes may also impose several short-run macroeconomic policy challenges, the nature of which remains underexplored. This paper investigates the mechanisms through which environmental taxes on fossil fuel usage can affect the main macroeconomic variables in the short-run. We concentrate on a particular mechanism: speculative storage. Formulating and using a dynamic stochastic general equilibrium (DSGE) model, calibrated for the United States, with an explicit storage facility and nominal rigidities, we show that in designing environmental tax policies it is crucial to account for the fact that fossil fuel prices are subject to speculation. The existence of forward-looking speculators in the model improves the effectiveness of tax policies in reducing fossil fuel usage. Improved policy effectiveness, however, is costly: it drives inflation and interest rates up, while impeding output. Based on this tradeoff, we seek an answer to the question how monetary policy should interact with environmental tax policies in our DSGE model of fossil fuel storage. We show that, in an environment with no speculative storers, monetary policy should respond to output along with CPI inflation in order to minimize the welfare losses brought by taxes. However, when the storage facility is activated, responding to output in the monetary policy rule becomes less desirable.

Fossil woods of Detarioideae subfamily (Fabaceae) from El Palmar Formation (Late Pleistocene) in South America

Science.gov (United States)

Ramos, R. Soledad; Brea, Mariana; Kröhling, Daniela M.

2017-11-01

The main aim of the present paper is to describe the first Detarioideae fossil woods from El Palmar Formation (Late Pleistocene) in the Uruguay River Basin (Entre Ríos, Argentina). This study is based on five silicified wood specimens preserved in fluvial deposits, which were transported from their growth site. Two new genera and species are described: Paraoxystigma concordiensis gen. nov and sp. nov. has medium-sized vessels, paratracheal axial parenchyma, heterocellular and multiseriate rays, and diffuse axial canals similar in size and shape to vessels, and Gossweilerodendroxylon palmariensis gen. nov and sp. nov. has medium-sized vessels, alternate intervessel pits, paratracheal and apotracheal axial parenchyma, homocellular and uni to-multiseriate rays, and small diffuse axial canals. These Detarioideae fossil records in south-eastern South America support the existence of a very old relationship with the extant West African forests. Eco-anatomical features observed in these fossil woods, along with the climatic information available from the Nearest Living Relatives (NLRs) comparison, suggest warm and humid climatic conditions for the upper-middle basin of the Uruguay River during some periods of the Late Pleistocene.

Beyond fossil calibrations: Realities of molecular clock practices in evolutionary biology

Directory of Open Access Journals (Sweden)

Christy Anna Hipsley

2014-05-01

Full Text Available Molecular-based divergence dating methods, or molecular clocks, are the primary neontological tool for estimating the temporal origins of clades. While the appropriate use of vertebrate fossils as external clock calibrations has stimulated heated discussions in the paleontological community, less attention has been given to the quality and implementation of other calibration types. In lieu of appropriate fossils, many studies rely on alternative sources of age constraints based on geological events, substitution rates and heterochronous sampling, as well as dates secondarily derived from previous analyses. To illustrate the breadth and frequency of calibration types currently employed, we conducted a literature survey of over 600 articles published from 2007 to 2013. Over half of all analyses implemented one or more fossil dates as constraints, followed by geological events and secondary calibrations (15% each. Vertebrate taxa were subjects of nearly half of all studies, while invertebrates and plants together accounted for 43%, followed by viruses, protists and fungi (3% each. Current patterns in calibration practices were disproportionate to the number of discussions on their proper use, particularly regarding plants and secondarily derived dates, which are both relatively neglected. Based on our survey, we provide a comprehensive overview of the latest approaches in clock calibration, and outline strengths and weaknesses associated with each. This critique should serve as a call to action for researchers across multiple communities, particularly those working on clades for which fossil records are poor, to develop their own guidelines regarding selection and implementation of alternative calibration types. This issue is particularly relevant now, as time-calibrated phylogenies are used for more than dating evolutionary origins, but often serve as the backbone of investigations into biogeography, diversity dynamics and rates of phenotypic

Insights into the diagenetic environment of fossil marine vertebrates of the Pisco Formation (late Miocene, Peru) from mineralogical and Sr-isotope data

Science.gov (United States)

Gioncada, A.; Petrini, R.; Bosio, G.; Gariboldi, K.; Collareta, A.; Malinverno, E.; Bonaccorsi, E.; Di Celma, C.; Pasero, M.; Urbina, M.; Bianucci, G.

2018-01-01

The late Miocene Pisco Formation of Peru is an outstanding example of richness and high-quality preservation of fossil marine vertebrates. In order to reconstruct the fossilization path, we present new textural, mineralogical and Sr-isotope data of diagenetic minerals formed in correspondence of fossil specimens such as marine vertebrates and mollusks. These fossil specimens were found at Cerro los Quesos, in the Ica Desert, within the diatomaceous strata of the Pisco Formation. Dolomite, gypsum, anhydrite and Mn minerals are the main phases found, while the calcium carbonate originally forming the mollusk valves is replaced by gypsum. An early formation of dolomite and of Mn minerals, triggered by the modifications of the geochemical environment due to organic matter degradation, is suggested by the textural relationships and is confirmed by the Sr isotopic ratio of dolomite, which agrees with that of seawater at the time of sedimentation. Instead, gypsum Sr isotopic ratios indicate a pre-Miocene seawater-derived brine circulating within the sedimentary sequence as a source for Sr. Oxidation of diagenetic sulfide causing a lowering of the pH of porewater is proposed as an explanation for Ca-carbonate dissolution. The diagenetic chemical environment was, nevertheless, favorable to bone preservation.

Species longevity in North American fossil mammals.

Science.gov (United States)

Prothero, Donald R

2014-08-01

Species longevity in the fossil record is related to many paleoecological variables and is important to macroevolutionary studies, yet there are very few reliable data on average species durations in Cenozoic fossil mammals. Many of the online databases (such as the Paleobiology Database) use only genera of North American Cenozoic mammals and there are severe problems because key groups (e.g. camels, oreodonts, pronghorns and proboscideans) have no reliable updated taxonomy, with many invalid genera and species and/or many undescribed genera and species. Most of the published datasets yield species duration estimates of approximately 2.3-4.3 Myr for larger mammals, with small mammals tending to have shorter species durations. My own compilation of all the valid species durations in families with updated taxonomy (39 families, containing 431 genera and 998 species, averaging 2.3 species per genus) yields a mean duration of 3.21 Myr for larger mammals. This breaks down to 4.10-4.39 Myr for artiodactyls, 3.14-3.31 Myr for perissodactyls and 2.63-2.95 Myr for carnivorous mammals (carnivorans plus creodonts). These averages are based on a much larger, more robust dataset than most previous estimates, so they should be more reliable for any studies that need species longevity to be accurately estimated. © 2013 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

Summary of the Snowmastodon Project Special Volume. A high-elevation, multi-proxy biotic and environmental record of MIS 6-4 from the Ziegler Reservoir fossil site, Snowmass Village, Colorado, USA

Science.gov (United States)

Miller, Ian M.; Pigati, Jeffrey S.; Scott Anderson, R.; Johnson, Kirk R.; Mahan, Shannon A.; Ager, Thomas A.; Baker, Richard G.; Blaauw, Maarten; Bright, Jordon; Brown, Peter M.; Bryant, Bruce; Calamari, Zachary T.; Carrara, Paul E.; Cherney, Michael D.; Demboski, John R.; Elias, Scott A.; Fisher, Daniel C.; Gray, Harrison J.; Haskett, Danielle R.; Honke, Jeffrey S.; Jackson, Stephen T.; Jiménez-Moreno, Gonzalo; Kline, Douglas; Leonard, Eric M.; Lifton, Nathaniel A.; Lucking, Carol; Gregory McDonald, H.; Miller, Dane M.; Muhs, Daniel R.; Nash, Stephen E.; Newton, Cody; Paces, James B.; Petrie, Lesley; Plummer, Mitchell A.; Porinchu, David F.; Rountrey, Adam N.; Scott, Eric; Sertich, Joseph J. W.; Sharpe, Saxon E.; Skipp, Gary L.; Strickland, Laura E.; Stucky, Richard K.; Thompson, Robert S.; Wilson, Jim

2014-11-01

In North America, terrestrial records of biodiversity and climate change that span Marine Oxygen Isotope Stage (MIS) 5 are rare. Where found, they provide insight into how the coupling of the ocean-atmosphere system is manifested in biotic and environmental records and how the biosphere responds to climate change. In 2010-2011, construction at Ziegler Reservoir near Snowmass Village, Colorado (USA) revealed a nearly continuous, lacustrine/wetland sedimentary sequence that preserved evidence of past plant communities between ~ 140 and 55 ka, including all of MIS 5. At an elevation of 2705 m, the Ziegler Reservoir fossil site also contained thousands of well-preserved bones of late Pleistocene megafauna, including mastodons, mammoths, ground sloths, horses, camels, deer, bison, black bear, coyotes, and bighorn sheep. In addition, the site contained more than 26,000 bones from at least 30 species of small animals including salamanders, otters, muskrats, minks, rabbits, beavers, frogs, lizards, snakes, fish, and birds. The combination of macro- and micro-vertebrates, invertebrates, terrestrial and aquatic plant macrofossils, a detailed pollen record, and a robust, directly dated stratigraphic framework shows that high-elevation ecosystems in the Rocky Mountains of Colorado are climatically sensitive and varied dramatically throughout MIS 5.

Divergence time estimates of mammals from molecular clocks and fossils: relevance of new fossil finds from India.

Science.gov (United States)

Prasad, G V R

2009-11-01

This paper presents a brief review of recent advances in the classification of mammals at higher levels using fossils and molecular clocks. It also discusses latest fossil discoveries from the Cretaceous - Eocene (66-55 m.y.) rocks of India and their relevance to our current understanding of placental mammal origins and diversifications.

Terrestrial origin of viviparity in mesozoic marine reptiles indicated by early triassic embryonic fossils.

Science.gov (United States)

Motani, Ryosuke; Jiang, Da-yong; Tintori, Andrea; Rieppel, Olivier; Chen, Guan-bao

2014-01-01

Viviparity in Mesozoic marine reptiles has traditionally been considered an aquatic adaptation. We report a new fossil specimen that strongly contradicts this traditional interpretation. The new specimen contains the oldest fossil embryos of Mesozoic marine reptile that are about 10 million years older than previous such records. The fossil belongs to Chaohusaurus (Reptilia, Ichthyopterygia), which is the oldest of Mesozoic marine reptiles (ca. 248 million years ago, Early Triassic). This exceptional specimen captures an articulated embryo in birth position, with its skull just emerged from the maternal pelvis. Its headfirst birth posture, which is unlikely to be a breech condition, strongly indicates a terrestrial origin of viviparity, in contrast to the traditional view. The tail-first birth posture in derived ichthyopterygians, convergent with the conditions in whales and sea cows, therefore is a secondary feature. The unequivocally marine origin of viviparity is so far not known among amniotes, a subset of vertebrate animals comprising mammals and reptiles, including birds. Therefore, obligate marine amniotes appear to have evolved almost exclusively from viviparous land ancestors. Viviparous land reptiles most likely appeared much earlier than currently thought, at least as early as the recovery phase from the end-Permian mass extinction.

Environmental evidence of fossil fuel pollution in Laguna Chica de San Pedro lake sediments (Central Chile)

International Nuclear Information System (INIS)

Chirinos, L.; Rose, N.L.; Urrutia, R.; Munoz, P.; Torrejon, F.; Torres, L.; Cruces, F.; Araneda, A.; Zaror, C.

2006-01-01

This paper describes lake sediment spheroidal carbonaceous particle (SCP) profiles from Laguna Chica San Pedro, located in the Biobio Region, Chile (36 o 51' S, 73 o 05' W). The earliest presence of SCPs was found at 16 cm depth, corresponding to the 1915-1937 period, at the very onset of industrial activities in the study area. No SCPs were found at lower depths. SCP concentrations in Laguna Chica San Pedro lake sediments were directly related to local industrial activities. Moreover, no SCPs were found in Galletue lake (38 o 41' S, 71 o 17.5' W), a pristine high mountain water body used here as a reference site, suggesting that contribution from long distance atmospheric transport could be neglected, unlike published data from remote Northern Hemisphere lakes. These results are the first SCP sediment profiles from Chile, showing a direct relationship with fossil fuel consumption in the region. Cores were dated using the 21 Pb technique. - The lake sediment record of SCPs shows the record of fossil-fuel derived pollution in Central Chile

Environmental evidence of fossil fuel pollution in Laguna Chica de San Pedro lake sediments (Central Chile)

Energy Technology Data Exchange (ETDEWEB)

Chirinos, L. [Centro de Ciencias Ambientales EULA-Chile, Universidad de Concepcion, PO Box 160-C, Concepcion (Chile)]. E-mail: lchirin@pucp.edu.pe; Rose, N.L. [Environmental Change Research Centre, University College London, 26 Bedford Way, London WG1HOAP (United Kingdom); Urrutia, R. [Centro de Ciencias Ambientales EULA-Chile, Universidad de Concepcion, PO Box 160-C, Concepcion (Chile); Munoz, P. [Departamento de Biologia Marina, Universidad Catolica del Norte, Larrondo 1281, Coquimbo (Chile); Torrejon, F. [Centro de Ciencias Ambientales EULA-Chile, Universidad de Concepcion, PO Box 160-C, Concepcion (Chile); Torres, L. [Departamento de Botanica, Universidad de Concepcion, Concepcion (Chile); Cruces, F. [Departamento de Botanica, Universidad de Concepcion, Concepcion (Chile); Araneda, A. [Centro de Ciencias Ambientales EULA-Chile, Universidad de Concepcion, PO Box 160-C, Concepcion (Chile); Zaror, C. [Facultad de Ingenieria Quimica, Universidad de Concepcion, Concepcion (Chile)

2006-05-15

This paper describes lake sediment spheroidal carbonaceous particle (SCP) profiles from Laguna Chica San Pedro, located in the Biobio Region, Chile (36{sup o} 51' S, 73{sup o} 05' W). The earliest presence of SCPs was found at 16 cm depth, corresponding to the 1915-1937 period, at the very onset of industrial activities in the study area. No SCPs were found at lower depths. SCP concentrations in Laguna Chica San Pedro lake sediments were directly related to local industrial activities. Moreover, no SCPs were found in Galletue lake (38{sup o} 41' S, 71{sup o} 17.5' W), a pristine high mountain water body used here as a reference site, suggesting that contribution from long distance atmospheric transport could be neglected, unlike published data from remote Northern Hemisphere lakes. These results are the first SCP sediment profiles from Chile, showing a direct relationship with fossil fuel consumption in the region. Cores were dated using the {sup 21}Pb technique. - The lake sediment record of SCPs shows the record of fossil-fuel derived pollution in Central Chile.

The fossil Osmundales (Royal Ferns—a phylogenetic network analysis, revised taxonomy, and evolutionary classification of anatomically preserved trunks and rhizomes

Directory of Open Access Journals (Sweden)

Benjamin Bomfleur

2017-07-01

Full Text Available The Osmundales (Royal Fern order originated in the late Paleozoic and is the most ancient surviving lineage of leptosporangiate ferns. In contrast to its low diversity today (less than 20 species in six genera, it has the richest fossil record of any extant group of ferns. The structurally preserved trunks and rhizomes alone are referable to more than 100 fossil species that are classified in up to 20 genera, four subfamilies, and two families. This diverse fossil record constitutes an exceptional source of information on the evolutionary history of the group from the Permian to the present. However, inconsistent terminology, varying formats of description, and the general lack of a uniform taxonomic concept renders this wealth of information poorly accessible. To this end, we provide a comprehensive review of the diversity of structural features of osmundalean axes under a standardized, descriptive terminology. A novel morphological character matrix with 45 anatomical characters scored for 15 extant species and for 114 fossil operational units (species or specimens is analysed using networks in order to establish systematic relationships among fossil and extant Osmundales rooted in axis anatomy. The results lead us to propose an evolutionary classification for fossil Osmundales and a revised, standardized taxonomy for all taxa down to the rank of (subgenus. We introduce several nomenclatural novelties: (1 a new subfamily Itopsidemoideae (Guaireaceae is established to contain Itopsidema, Donwelliacaulis, and Tiania; (2 the thamnopteroid genera Zalesskya, Iegosigopteris, and Petcheropteris are all considered synonymous with Thamnopteris; (3 12 species of Millerocaulis and Ashicaulis are assigned to modern genera (tribe Osmundeae; (4 the hitherto enigmatic Aurealcaulis is identified as an extinct subgenus of Plenasium; and (5 the poorly known Osmundites tuhajkulensis is assigned to Millerocaulis. In addition, we consider Millerocaulis

The fossil Osmundales (Royal Ferns)-a phylogenetic network analysis, revised taxonomy, and evolutionary classification of anatomically preserved trunks and rhizomes.

Science.gov (United States)

Bomfleur, Benjamin; Grimm, Guido W; McLoughlin, Stephen

2017-01-01

The Osmundales (Royal Fern order) originated in the late Paleozoic and is the most ancient surviving lineage of leptosporangiate ferns. In contrast to its low diversity today (less than 20 species in six genera), it has the richest fossil record of any extant group of ferns. The structurally preserved trunks and rhizomes alone are referable to more than 100 fossil species that are classified in up to 20 genera, four subfamilies, and two families. This diverse fossil record constitutes an exceptional source of information on the evolutionary history of the group from the Permian to the present. However, inconsistent terminology, varying formats of description, and the general lack of a uniform taxonomic concept renders this wealth of information poorly accessible. To this end, we provide a comprehensive review of the diversity of structural features of osmundalean axes under a standardized, descriptive terminology. A novel morphological character matrix with 45 anatomical characters scored for 15 extant species and for 114 fossil operational units (species or specimens) is analysed using networks in order to establish systematic relationships among fossil and extant Osmundales rooted in axis anatomy. The results lead us to propose an evolutionary classification for fossil Osmundales and a revised, standardized taxonomy for all taxa down to the rank of (sub)genus. We introduce several nomenclatural novelties: (1) a new subfamily Itopsidemoideae (Guaireaceae) is established to contain Itopsidema , Donwelliacaulis , and Tiania ; (2) the thamnopteroid genera Zalesskya , Iegosigopteris , and Petcheropteris are all considered synonymous with Thamnopteris ; (3) 12 species of Millerocaulis and Ashicaulis are assigned to modern genera (tribe Osmundeae); (4) the hitherto enigmatic Aurealcaulis is identified as an extinct subgenus of Plenasium ; and (5) the poorly known Osmundites tuhajkulensis is assigned to Millerocaulis . In addition, we consider Millerocaulis

Charles Darwin's beagle voyage, fossil vertebrate succession, and "the gradual birth & death of species".

Science.gov (United States)

Brinkman, Paul D

2010-01-01

The prevailing view among historians of science holds that Charles Darwin became a convinced transmutationist only in the early spring of 1837, after his Beagle collections had been examined by expert British naturalists. With respect to the fossil vertebrate evidence, some historians believe that Darwin was incapable of seeing or understanding the transmutationist implications of his specimens without the help of Richard Owen. There is ample evidence, however, that he clearly recognized the similarities between several of the fossil vertebrates he collected and some of the extant fauna of South America before he returned to Britain. These comparisons, recorded in his correspondence, his diary and his notebooks during the voyage, were instances of a phenomenon that he later called the "law of the succession of types." Moreover, on the Beagle, he was following a geological research agenda outlined in the second volume of Charles Lyell's Principles of Geology, which implies that paleontological data alone could provide an insight into the laws which govern the appearance of new species. Since Darwin claims in On the Origin of Species that fossil vertebrate succession was one of the key lines of evidence that led him to question the fixity of species, it seems certain that he was seriously contemplating transmutation during the Beagle voyage. If so, historians of science need to reconsider both the role of Britain's expert naturalists and the importance of the fossil vertebrate evidence in the development of Darwin's ideas on transmutation.

Security of supply: a neglected fossil fuel externality

International Nuclear Information System (INIS)

Cavallo, A.J.

1995-01-01

Various groups have attempted to set a monetary value on the externalities of fossil fuel usage based on damages caused by emissions of particulates, sulfur dioxide, and oxides of nitrogen and carbon. One externality that has been neglected in this type of analysis, however, is the cost of maintaining a secure supply of fossil fuels. Military expenditures for this purpose are relatively easy to quantify based on US Department of Defense and Office of Management and Budget figures, and amount to between $1 and more than $3 per million Btu, based on total fossil fuel consumption in the US. Open acknowledgment of such expenses would, at the very least, have a profound effect on the perceived competitiveness of all non-fossil fuel technologies. It should also provide a simple and easily comprehended rationale for an energy content (Btu) charge on all fossil fuels. (Author)

The Westphalian D fossil lepidodendrid forest at Table Head, Sydney Basin, Nova Scotia: Sedimentology, paleoecology and floral response to changing edaphic conditions

Science.gov (United States)

Calder, J.H.; Gibling, M.R.; Eble, C.F.; Scott, A.C.; MacNeil, D.J.

1996-01-01

Strata of Westphalian D age on the western coast of the Sydney Basin expose a fossil forest of approximately 30 lepidodendrid trees within one of several clastic splits of the Harbour Seam. A mutidisciplinary approach was employed to interpret the origins of the coal bed, the depositional history of the site and the response of the fossil forest to changing edaphic conditions. The megaspore and miospore records indicate that the mire vegetation was dominated by arboreous lycopsids, especially Paralycopodites, with subdominant tree ferns. Petrographic, palynological and geochemical evidence suggest that the Harbour coal bed at Table Head originated as a rheotrophic (cf. planar) mire (eutric histosol). The mire forest is interpreted to have been engulfed by prograding distributary-channel sediments; sparse protist assemblages are suggestive of a freshwater delta-plain lake environment occasionally in contact with brackish waters. Lepidodendrids persisted as site colonizers of clastic substrates even after burial of the rheotrophic peatland and influenced the morphology of deposited sediment, but apparently were unable to colonize distributary channels. Equivocal taxonomic data (compression fossils) show the fossil forest to have been composed of both monocarpic (Lepidodendron) and polycarpic (Diaphorodendron, Paralycopodites, ?Sigillaria) lycopsids, genera recorded in the palynology of the uppermost ply of the underlying coal bed. Comparatively rare within the clastic beds of the fossil forest, however, is the stem compression of Paralycopodites, whose dispersed megapores and miospores dominate the underlying coal bed. Tree diameter data recorded equivalent to breast height indicate a forest of mixed age. These data would appear to suggest that some lepidodendrids employing a polycarpic reproductive strategy were better able to cross the ecological barrier imposed between peat and clastic substrates. Foliar compressions indicate that an understory or stand of

Fossil energy biotechnology: A research needs assessment. Final report

Energy Technology Data Exchange (ETDEWEB)

1993-11-01

The Office of Program Analysis of the US Department of Energy commissioned this study to evaluate and prioritize research needs in fossil energy biotechnology. The objectives were to identify research initiatives in biotechnology that offer timely and strategic options for the more efficient and effective uses of the Nation`s fossil resource base, particularly the early identification of new and novel applications of biotechnology for the use or conversion of domestic fossil fuels. Fossil energy biotechnology consists of a number of diverse and distinct technologies, all related by the common denominator -- biocatalysis. The expert panel organized 14 technical subjects into three interrelated biotechnology programs: (1) upgrading the fuel value of fossil fuels; (2) bioconversion of fossil feedstocks and refined products to added value chemicals; and, (3) the development of environmental management strategies to minimize and mitigate the release of toxic and hazardous petrochemical wastes.

Stratigraphy, correlation, and age estimates for fossils from Area 123, Koobi Fora.

Science.gov (United States)

Feibel, Craig S; Lepre, Christopher J; Quinn, Rhonda L

2009-08-01

Geological data from the Bura Hasuma region at Koobi Fora provide important constraints for estimating the ages of hominin fossils recovered there, including the cranium KNM-ER 1813. Strata of the upper Burgi, KBS, and Okote members in this part of Koobi Fora reflect three depositional regimes driven by changing paleogeography through time. The upper Burgi and lowermost KBS sequence in the southern Bura Hasuma region accumulated in a lacustrine to delta front setting, with highly localized depositional patterns, limiting the lateral extent of lithostratigraphic markers. Farther north, uppermost upper Burgi through KBS member strata document a fluctuating lake margin, with complex facies patterns. This interval is marked by laterally extensive lithostratigraphic markers, including molluscan packstones, beach sandstones, and stromatolite beds. The uppermost KBS and Okote members show a transition to dominantly fluvial character, with localized and discontinuous accumulation. An age model for the richly fossiliferous Area 123 sequence demonstrates the complexity of terrestrial accumulation patterns. Early lacustrine and delta front accumulation is marked by fairly continuous sedimentation, and high accumulation rates (up to ca. 91 cm/k.yr.). The fluctuating lake margin interval reflects lower sedimentation rates coupled with intervals of exposure, decreasing accumulation significantly (to ca. 13 cm/k.yr.). The capping fluvial interval is marked by significant erosion surfaces, breaks which may drop the overall accumulation rate even lower (ca. 0.3 cm/k.yr.). The data provided here establish a geological framework at odds with a recent proposal of ages considerably younger (by ca. 250 k.yr.) for many of the fossils from Area 123 and elsewhere. Tests of age models demonstrate that the younger ages are not possible. While minor refinements to age estimates for fossils are indicated by improved chronostratigraphic control, in the case of KNM-ER 1813, an age of younger

Fossil energy: From laboratory to marketplace

International Nuclear Information System (INIS)

1992-03-01

The purpose of this work is to provide a summary description of the role of advanced research in the overall Fossil Energy R ampersand D program successes. It presents the specific Fossil Energy advanced research products that have been adopted commercially or fed into other R ampersand D programs as part of the crosscutting enabling technology base upon which advanced systems are based

Lessons learned from fossil FAC assessments

Energy Technology Data Exchange (ETDEWEB)

Dooley, R. Barry; Shields, Kevin J. [Structural Integrity Associates, Inc., Oakville, ON (Canada); Shulder, Stephen J. [Structural Integrity Associates, Inc., Annapolis, MD (United States)

2010-09-15

In their work the authors have noted great diversity in the Flow-Accelerated Corrosion (FAC) Programs used at conventional fossil power plants. The results and findings of FAC Program assessments conducted at 22 conventional plants are summarized and discussed. By comparing the FAC Program characteristics and relevant unit features with damage and failure experiences, a number of common factors requiring attention from fossil utility organizations have been identified. The assessment experiences have also provided a picture of trends in specific FAC activities and general awareness within the conventional fossil fleet. One of the most important aspects of these studies is that while a few new locations of FAC have been found, there is some consolidation of the most frequently found locations. (orig.)

FOSSIL SYSTEMS IN THE 400d CLUSTER CATALOG

International Nuclear Information System (INIS)

Voevodkin, Alexey; Borozdin, Konstantin; Heitmann, Katrin; Habib, Salman; Vikhlinin, Alexey; Mescheryakov, Alexander; Burenin, Rodion; Hornstrup, Allan

2010-01-01

We report the discovery of seven new fossil systems in the 400d cluster survey. Our search targets nearby, z ≤ 0.2, and X-ray bright, L X ≥ 10 43 erg s -1 , clusters of galaxies. Where available, we measure the optical luminosities from Sloan Digital Sky Survey images, thereby obtaining uniform sets of both X-ray and optical data. Our selection criteria identify 12 fossil systems, out of which five are known from previous studies. While in general agreement with earlier results, our larger sample size allows us to put tighter constraints on the number density of fossil clusters. It has been previously reported that fossil groups are more X-ray bright than other X-ray groups of galaxies for the same optical luminosity. We find, however, that the X-ray brightness of massive fossil systems is consistent with that of the general population of galaxy clusters and follows the same L X -L opt scaling relation.

Nitrogen-fixing symbiosis inferred from stable isotope analysis of fossil tree rings from the Oligocene of Ethiopia

Science.gov (United States)

Erik L. Gulbranson; Bonnie F. Jacobs; William C. Hockaday; Michael C. Wiemann; Lauren A. Michel; Kaylee Richards; John W. Kappelman

2017-01-01

The acquisition of reduced nitrogen (N) is essential for plant life, and plants have developed numerous strategies and symbioses with soil microorganisms to acquire this form of N. The evolutionary history of specific symbiotic relationships of plants with soil bacteria, however, lacks evidence from the fossil record confirming these mutualistic relationships. Here we...

Fossil Fuels, Backstop Technologies, and Imperfect Substitution

NARCIS (Netherlands)

van der Meijden, G.C.; Pittel, Karen; van der Ploeg, Frederick; Withagen, Cees

2014-01-01

This chapter studies the transition from fossil fuels to backstop technologies in a general equilibrium model in which growth is driven by research and development. The analysis generalizes the existing literature by allowing for imperfect substitution between fossil fuels and the new energy

The role of fossil organic matter in the ecosystem development of post-mining sites revealed by isotope analyses

Science.gov (United States)

Jandova, Katerina; Hyodo, Fujio; Vindušková, Olga; Moradi, Jabbar; Frouz, Jan

2017-04-01

Sediments rich in kerogen ( 19 Ma old, 14C-free) are present in the overburden at post-mining area in Western Bohemia, near Sokolov city, the Czech Republic. There are two successional chronosequences, an alder reclamation and spontaneous succession, consisting of sites that differ in time since heaping. Both chronosequences accumulate recent organic matter over time, although the process is initially faster at reclamation. We hypothesized that (i) radiocarbon age of soil organic matter would be decreasing with time since spoil heaping; (ii) the detrital food web would show the assimilation of fossil carbon by heterotrophic organisms in the initial stages of succession when fossil organic matter is the predominant source of carbon; (iii) the isotopic track of fossil organic matter in the detrital food web would be more prominent at sites with lower vegetation cover and litter production. Nitrogen isotopic ratios of soils were high at the young sites and the decrease in δ15N was correlated with the increase in content of recent organic carbon. Nitrogen isotopic ratios of soil detritivores equalled to that of tree leaves at reclamation but were higher at successional sites. Possibly, other food sources were used apart from tree leaves litter at the latter. Interestingly, soil animals but not primary producers were 14C depleted in the youngest relative to the oldest sites. The depletion in 14C of detritivores relative to primary producers was likely due to the geophagy behaviour of the millipedes at the young sites where fossil organic matter is the largest carbon pool.

Aluminum-26 in the early solar system - Fossil or fuel

Science.gov (United States)

Lee, T.; Papanastassiou, D. A.; Wasserburg, G. J.

1977-01-01

The isotopic composition of Mg was measured in different phases of a Ca-Al-rich inclusion in the Allende meteorite. Large excesses of Mg-26 of up to 10% were found. These excesses correlate strictly with the Al-27/Mg-24 ratio for four coexisting phases with distinctive chemical compositions. Models of in situ decay of Al-26 within the solar system and of mixing of interstellar dust grains containing fossil Al-26 with normal solar system material are presented. The observed correlation provides definitive evidence for the presence of Al-26 in the early solar system. This requires either injection of freshly synthesized nucleosynthetic material into the solar system immediately before condensation and planet formation, or local production within the solar system by intense activity of the early sun. Planets promptly produced from material with the inferred Al-26/Al-27 would melt within about 300,000 years.

Fossil Energy Materials Program conference proceedings

Energy Technology Data Exchange (ETDEWEB)

Judkins, R.R. (comp.)

1987-08-01

The US Department of Energy Office of Fossil Energy has recognized the need for materials research and development to assure the adequacy of materials of construction for advanced fossil energy systems. The principal responsibility for identifying needed materials research and for establishing a program to address these needs resides within the Office of Technical Coordination. That office has established the Advanced Research and Technology Development (AR and TD) Fossil Energy Materials Program to fulfill that responsibility. In addition to the AR and TD Materials Program, which is designed to address in a generic way the materials needs of fossil energy systems, specific materials support activities are also sponsored by the various line organizations such as the Office of Coal Gasification. A conference was held at Oak Ridge, Tennessee on May 19-21, 1987, to present and discuss the results of program activities during the past year. The conference program was organized in accordance with the research thrust areas we have established. These research thrust areas include structural ceramics (particularly fiber-reinforced ceramic composites), corrosion and erosion, and alloy development and mechanical properties. Eighty-six people attended the conference. Papers have been entered individually into EDB and ERA. (LTN)

Fossil Energy Program semiannual progress report for October 1991--March 1992

Energy Technology Data Exchange (ETDEWEB)

Judkins, R.R.

1992-11-01

This report covers progress made during the period October 1, 1991, through March 31, 1992, for research and development projects that contribute to the advancement of various fossil energy technologies. Projects on the Fossil Energy Program are supported by the DOE Office of Fossil Energy, the DOE Morgantown Energy Technology Center, the DOE Pittsburgh Energy Technology Center, the DOE Fossil Energy Clean Coal Technology Program, the DOE Office of Basic Energy Sciences, the DOE Fossil Energy Office of Petroleum Reserves, the DOE Fossil Energy Naval Petroleum and Oil Shale Reserves, and the US Agency for International Development. The Fossil Energy Program organization chart is shown in the appendix. Topics discussed are under the following projects: materials research and developments; environmental analysis support; coal conversion development; coal combustion research; and fossil fuels supplies modeling and research.

Use of Micro-Computed Tomography for Dental Studies in Modern and Fossil Odontocetes: Potential Applications and Limitations

Directory of Open Access Journals (Sweden)

Carolina Loch

2013-10-01

Full Text Available Teeth are important elements in studies of modern and fossil Cetacea (whales, dolphins, providing information on feeding habits, estimations of age and phylogenetic relationships. The growth layer groups (GLGs recorded in dentine have demonstrated application for aging studies, but also have the potential to elucidate life history phenomena such as metabolic or physiologic events. Micro-Computed Tomography (Micro-CT is a non-invasive and non-destructive technique that allows 3-dimensional study of mineralized tissues, such as human teeth, and their physical properties. Teeth from extant dolphins (Cetacea: Odontoceti and some fossil odontocetes were scanned in a Skyscan 1172 Micro-CT desktop system. X-rays were generated at 100 kV and 100 µA for extant samples, and at 80kV and 124 µA for fossils. 0.5 mm thick aluminum and copper filters were used in the beam. Reconstructed images were informative for most extant species, showing a good resolution of the enamel layer, dentine and pulp cavity. Greyscale changes in the dentinal layers were not resolved enough to show GLGs. Visualization of the internal structure in fossil cetacean teeth depended on the degree of diagenetic alteration in the specimen; undifferentiated enamel and dentine regions probably reflect secondary mineralization. However, internal details were finely resolved for one fossil specimen, showing the enamel, internal layers of dentine and the pulp cavity. Micro-CT has been proven to be a useful tool for resolving the internal morphology of fossil and extant teeth of cetaceans before they are sectioned for other morphological analyses; however some methodological refinements are still necessary to allow better resolution of dentine for potential application in non-destructive age determination studies.

Fossiler i Grønland. 2. del

DEFF Research Database (Denmark)

Harper, David Alexander Taylor; Lindow, Bent Erik Kramer

2009-01-01

Dette er anden og sidste del af POST Greenlands serie om fossiler i Grønland med tre frimærker, der beretter om de mange og spændende fossilfund fra Grønland. Mærkerne fortsætter vores rejse gennem nogle af nøglebegivenhederne i livets historie, smukt illustreret af endnu flere unikke fossiler....... Disse tre fossiler, en plante, et bløddyr og et hvirveldyr, er fra de yngre aflejringer i Grønland med aldre spændende fra for 200 millioner og indtil kun 8.000 år siden....

Fossilization Processes in Thermal Springs

Science.gov (United States)

Farmer, Jack D.; Cady, Sherry; Desmarais, David J.; Chang, Sherwood (Technical Monitor)

1995-01-01

To create a comparative framework for the study of ancient examples, we have been carrying out parallel studies of the microbial biosedimentology, taphonomy and geochemistry of modem and sub-Recent thermal spring deposits. One goal of the research is the development of integrated litho- and taphofacies models for siliceous and travertline sinters. Thermal springs are regarded as important environments for the origin and early evolution of life on Earth, and we seek to utilize information from the fossil record to reconstruct the evolution of high temperature ecosystems. Microbial contributions to the fabric of thermal spring sinters occur when population growth rates keep pace with, or exceed rates of inorganic precipitation, allowing for the development of continuous biofilms or mats. In siliceous thermal springs, microorganisms are typically entombed while viable. Modes of preservation reflect the balance between rates of organic matter degradation, silica precipitation and secondary infilling. Subaerial sinters are initially quite porous and permeable and at temperatures higher than about 20 C, organic materials are usually degraded prior to secondary infilling of sinter frameworks. Thus, organically-preserved microfossils are rare and fossil information consists of characteristic biofabrics formed by the encrustation and underplating of microbial mat surfaces. This probably accounts for the typically low total organic carbon values observed in thermal spring deposits. In mid-temperature, (approx. 35 - 59 C) ponds and outflows, the surface morphology of tufted Phormidium mats is preserved through mat underplating by thin siliceous: crusts. Microbial taxes lead to clumping of ceils and/or preferred filament orientations that together define higher order composite fabrics in thermal spring stromatolites (e.g. network, coniform, and palisade). At lower temperatures (less than 35 C), Calothrix mats cover shallow terracette pools forming flat carpets or pustular

Seawater 234U/238U recorded by modern and fossil corals

Science.gov (United States)

Chutcharavan, Peter M.; Dutton, Andrea; Ellwood, Michael J.

2018-03-01

U-series dating of corals is a crucial tool for generating absolute chronologies of Late Quaternary sea-level change and calibrating the radiocarbon timescale. Unfortunately, coralline aragonite is susceptible to post-depositional alteration of its primary geochemistry. One screening technique used to identify unaltered corals relies on the back-calculation of initial 234U/238U activity (δ234Ui) at the time of coral growth and implicitly assumes that seawater δ234U has remained constant during the Late Quaternary. Here, we test this assumption using the most comprehensive compilation to date of coral U-series measurements. Unlike previous compilations, this study normalizes U-series measurements to the same decay constants and corrects for offsets in interlaboratory calibrations, thus reducing systematic biases between reported δ234U values. Using this approach, we reassess (a) the value of modern seawater δ234U, and (b) the evolution of seawater δ234U over the last deglaciation. Modern coral δ234U values (145.0 ± 1.5‰) agree with previous measurements of seawater and modern corals only once the data have been normalized. Additionally, fossil corals in the surface ocean display δ234Ui values that are ∼5-7‰ lower during the last glacial maximum regardless of site, taxon, or diagenetic setting. We conclude that physical weathering of U-bearing minerals exposed during ice sheet retreat drives the increase in δ234U observed in the oceans, a mechanism that is consistent with the interpretation of the seawater Pb-isotope signal over the same timescale.

The fossil Osmundales (Royal Ferns)—a phylogenetic network analysis, revised taxonomy, and evolutionary classification of anatomically preserved trunks and rhizomes

Science.gov (United States)

2017-01-01

The Osmundales (Royal Fern order) originated in the late Paleozoic and is the most ancient surviving lineage of leptosporangiate ferns. In contrast to its low diversity today (less than 20 species in six genera), it has the richest fossil record of any extant group of ferns. The structurally preserved trunks and rhizomes alone are referable to more than 100 fossil species that are classified in up to 20 genera, four subfamilies, and two families. This diverse fossil record constitutes an exceptional source of information on the evolutionary history of the group from the Permian to the present. However, inconsistent terminology, varying formats of description, and the general lack of a uniform taxonomic concept renders this wealth of information poorly accessible. To this end, we provide a comprehensive review of the diversity of structural features of osmundalean axes under a standardized, descriptive terminology. A novel morphological character matrix with 45 anatomical characters scored for 15 extant species and for 114 fossil operational units (species or specimens) is analysed using networks in order to establish systematic relationships among fossil and extant Osmundales rooted in axis anatomy. The results lead us to propose an evolutionary classification for fossil Osmundales and a revised, standardized taxonomy for all taxa down to the rank of (sub)genus. We introduce several nomenclatural novelties: (1) a new subfamily Itopsidemoideae (Guaireaceae) is established to contain Itopsidema, Donwelliacaulis, and Tiania; (2) the thamnopteroid genera Zalesskya, Iegosigopteris, and Petcheropteris are all considered synonymous with Thamnopteris; (3) 12 species of Millerocaulis and Ashicaulis are assigned to modern genera (tribe Osmundeae); (4) the hitherto enigmatic Aurealcaulis is identified as an extinct subgenus of Plenasium; and (5) the poorly known Osmundites tuhajkulensis is assigned to Millerocaulis. In addition, we consider Millerocaulis stipabonettiorum a

Export of nutrient rich Northern Component Water preceded early Oligocene Antarctic glaciation

Science.gov (United States)

Coxall, Helen K.; Huck, Claire E.; Huber, Matthew; Lear, Caroline H.; Legarda-Lisarri, Alba; O'Regan, Matt; Sliwinska, Kasia K.; van de Flierdt, Tina; de Boer, Agatha M.; Zachos, James C.; Backman, Jan

2018-03-01

The onset of the North Atlantic Deep Water formation is thought to have coincided with Antarctic ice-sheet growth about 34 million years ago (Ma). However, this timing is debated, in part due to questions over the geochemical signature of the ancient Northern Component Water (NCW) formed in the deep North Atlantic. Here we present detailed geochemical records from North Atlantic sediment cores located close to sites of deep-water formation. We find that prior to 36 Ma, the northwestern Atlantic was stratified, with nutrient-rich, low-salinity bottom waters. This restricted basin transitioned into a conduit for NCW that began flowing southwards approximately one million years before the initial Antarctic glaciation. The probable trigger was tectonic adjustments in subarctic seas that enabled an increased exchange across the Greenland-Scotland Ridge. The increasing surface salinity and density strengthened the production of NCW. The late Eocene deep-water mass differed in its carbon isotopic signature from modern values as a result of the leakage of fossil carbon from the Arctic Ocean. Export of this nutrient-laden water provided a transient pulse of CO2 to the Earth system, which perhaps caused short-term warming, whereas the long-term effect of enhanced NCW formation was a greater northward heat transport that cooled Antarctica.

Fossil avian eggshell preserves ancient DNA

DEFF Research Database (Denmark)

Oskam, Charlotte L; Haile, James Seymour; McLay, Emma

2010-01-01

Owing to exceptional biomolecule preservation, fossil avian eggshell has been used extensively in geochronology and palaeodietary studies. Here, we show, to our knowledge, for the first time that fossil eggshell is a previously unrecognized source of ancient DNA (aDNA). We describe the successful...... isolation and amplification of DNA from fossil eggshell up to 19 ka old. aDNA was successfully characterized from eggshell obtained from New Zealand (extinct moa and ducks), Madagascar (extinct elephant birds) and Australia (emu and owl). Our data demonstrate excellent preservation of the nucleic acids......, evidenced by retrieval of both mitochondrial and nuclear DNA from many of the samples. Using confocal microscopy and quantitative PCR, this study critically evaluates approaches to maximize DNA recovery from powdered eggshell. Our quantitative PCR experiments also demonstrate that moa eggshell has...

Proceedings of the Seventh Annual Conference on Fossil Energy Materials. Fossil Energy AR and TD Materials Program

Energy Technology Data Exchange (ETDEWEB)

Cole, N.C.; Judkins, R.R. [comps.

1993-07-01

Objective of the AR&TD Materials Program is to conduct research and development on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. The 37 papers are arranged into 3 sessions: ceramics, new alloys/intermetallics, and new alloys/advanced austenitics. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

Coastal Microstructure: From Active Overturn to Fossil Turbulence

Science.gov (United States)

Tau Leung, Pak

2011-11-01

The Remote Anthropogenic Sensing Program was a five year effort (2001- 2005) to examine subsurface phenomena related to a sewage outfall off the coast of Oahu, Hawaii. This research has implications for basic ocean hydrodynamics, particularly for a greatly improved understanding of the evolution of turbulent patches. It was the first time a microstructure measurement was used to study such a buoyancy-driven turbulence generated by a sea-floor diffuser. In 2004, two stations were selected to represent the near field and ambient conditions. They have nearly identical bathymetrical and hydrographical features and provide an ideal environment for a control experiment. Repeated vertical microstructure measurements were performed at both stations for 20 days. A time series of physical parameters was collected and used for statistical analysis. After comparing the data from both stations, it can be concluded that the turbulent mixing generated by the diffuser contributes to the elevated dissipation rate observed in the pycnocline and bottom boundary layer. To further understand the mixing processes in both regions, data were plotted on a Hydrodynamic Phase Diagram. The overturning stages of the turbulent patches are identified by Hydrodynamic Phase Diagram. This technique provides detailed information on the evolution of the turbulent patches from active overturns to fossilized scalar microstructures in the water column. Results from this study offer new evidence to support the fossil turbulence theory. This study concluded that: 1. Field Data collected near a sea-floor outfall diffuser show that turbulent patches evolve from active (overturning) to fossil (buoyancy-inhibited) stages, consistent with the process of turbulent patch evolution proposed by fossil turbulence theory. 2. The data show that active (overturning) and fossil (buoyancy-inhibited) patches have smaller length scales than the active+fossil (intermediate) stage of patch evolution, consistent with fossil

Fossil fuel derivatives with reduced carbon. Phase I final report

Energy Technology Data Exchange (ETDEWEB)

Kennel, E.B.; Zondlo, J.W.; Cessna, T.J.

1999-06-30

This project involves the simultaneous production of clean fossil fuel derivatives with reduced carbon and sulfur, along with value-added carbon nanofibers. This can be accomplished because the nanofiber production process removes carbon via a catalyzed pyrolysis reaction, which also has the effect of removing 99.9% of the sulfur, which is trapped in the nanofibers. The reaction is mildly endothermic, meaning that net energy production with real reductions in greenhouse emissions are possible. In Phase I research, the feasibility of generating clean fossil fuel derivatives with reduced carbon was demonstrated by the successful design, construction and operation of a facility capable of utilizing coal as well as natural gas as an inlet feedstock. In the case of coal, for example, reductions in CO{sub 2} emissions can be as much as 70% (normalized according to kilowatts produced), with the majority of carbon safely sequestered in the form of carbon nanofibers or coke. Both of these products are value-added commodities, indicating that low-emission coal fuel can be done at a profit rather than a loss as is the case with most clean-up schemes. The main results of this project were as follows: (1) It was shown that the nanofiber production process produces hydrogen as a byproduct. (2) The hydrogen, or hydrogen-rich hydrocarbon mixture can be consumed with net release of enthalpy. (3) The greenhouse gas emissions from both coal and natural gas are significantly reduced. Because coal consumption also creates coke, the carbon emission can be reduced by 75% per kilowatt-hour of power produced.

The first evidence of trace fossils and pseudo-fossils in the continental interlava volcaniclastic sediments on the Faroe Islands

Czech Academy of Sciences Publication Activity Database

Pokorný, R.; Krmíček, Lukáš; Árting, U. E.

2015-01-01

Roč. 63, č. 1 (2015), s. 45-57 ISSN 2245-7070 Institutional support: RVO:67985831 Keywords : Faroe Islands * trace fossils * pseudo- fossils * volcaniclastic sediments Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.889, year: 2015 http://2dgf.dk/xpdf/bull63-45-57.pdf

Fossil Energy Program semiannual progress report for April 1992-- September 1992

Energy Technology Data Exchange (ETDEWEB)

Judkins, R.R.

1992-12-01

This report covers progress made during the period April 1, 1992, through September 30, 1992, for research and development projects that contribute to the advancement of various fossil energy technologies. Projects on the Fossil Energy Program are supported by the DOE Office of Fossil Energy, the DOE Morgantown Energy Technology Center, the DOE Pittsburgh Energy Technology Center, the DOE Fossil Energy Clean Coal Technology Program, the DOE Office of Basic Energy Sciences, the DOE Fossil Energy Office of Petroleum Reserves, the DOE Fossil Energy Office of Naval Petroleum and Oil Shale Reserves, and the US Agency for International Development.

Constraints of fossil fuels depletion on global warming projections

International Nuclear Information System (INIS)

Chiari, Luca; Zecca, Antonio

2011-01-01

A scientific debate is in progress about the intersection of climate change with the new field of fossil fuels depletion geology. Here, new projections of atmospheric CO 2 concentration and global-mean temperature change are presented, should fossil fuels be exploited at a rate limited by geological availability only. The present work starts from the projections of fossil energy use, as obtained from ten independent sources. From such projections an upper bound, a lower bound and an ensemble mean profile for fossil CO 2 emissions until 2200 are derived. Using the coupled gas-cycle/climate model MAGICC, the corresponding climatic projections out to 2200 are obtained. We find that CO 2 concentration might increase up to about 480 ppm (445-540 ppm), while the global-mean temperature increase w.r.t. 2000 might reach 1.2 deg. C (0.9-1.6 deg. C). However, future improvements of fossil fuels recovery and discoveries of new resources might lead to higher emissions; hence our climatic projections are likely to be underestimated. In the absence of actions of emissions reduction, a level of dangerous anthropogenic interference with the climate system might be already experienced toward the middle of the 21st century, despite the constraints imposed by the exhaustion of fossil fuels. - Highlights: → CO 2 and global temperature are projected under fossil fuels exhaustion scenarios. → Temperature is projected to reach a minimum of 2 deg. C above pre-industrial. → Temperature projections are possibly lower than the IPCC ones. → Fossil fuels exhaustion will not avoid dangerous global warming.

Constraints of fossil fuels depletion on global warming projections

Energy Technology Data Exchange (ETDEWEB)

Chiari, Luca, E-mail: chiari@science.unitn.it [Department of Physics, University of Trento, Via Sommarive 14, 38123 Povo (Italy); Zecca, Antonio, E-mail: zecca@science.unitn.it [Department of Physics, University of Trento, Via Sommarive 14, 38123 Povo (Italy)

2011-09-15

A scientific debate is in progress about the intersection of climate change with the new field of fossil fuels depletion geology. Here, new projections of atmospheric CO{sub 2} concentration and global-mean temperature change are presented, should fossil fuels be exploited at a rate limited by geological availability only. The present work starts from the projections of fossil energy use, as obtained from ten independent sources. From such projections an upper bound, a lower bound and an ensemble mean profile for fossil CO{sub 2} emissions until 2200 are derived. Using the coupled gas-cycle/climate model MAGICC, the corresponding climatic projections out to 2200 are obtained. We find that CO{sub 2} concentration might increase up to about 480 ppm (445-540 ppm), while the global-mean temperature increase w.r.t. 2000 might reach 1.2 deg. C (0.9-1.6 deg. C). However, future improvements of fossil fuels recovery and discoveries of new resources might lead to higher emissions; hence our climatic projections are likely to be underestimated. In the absence of actions of emissions reduction, a level of dangerous anthropogenic interference with the climate system might be already experienced toward the middle of the 21st century, despite the constraints imposed by the exhaustion of fossil fuels. - Highlights: > CO{sub 2} and global temperature are projected under fossil fuels exhaustion scenarios. > Temperature is projected to reach a minimum of 2 deg. C above pre-industrial. > Temperature projections are possibly lower than the IPCC ones. > Fossil fuels exhaustion will not avoid dangerous global warming.

New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens.

Science.gov (United States)

Hublin, Jean-Jacques; Ben-Ncer, Abdelouahed; Bailey, Shara E; Freidline, Sarah E; Neubauer, Simon; Skinner, Matthew M; Bergmann, Inga; Le Cabec, Adeline; Benazzi, Stefano; Harvati, Katerina; Gunz, Philipp

2017-06-07

Fossil evidence points to an African origin of Homo sapiens from a group called either H. heidelbergensis or H. rhodesiensis. However, the exact place and time of emergence of H. sapiens remain obscure because the fossil record is scarce and the chronological age of many key specimens remains uncertain. In particular, it is unclear whether the present day 'modern' morphology rapidly emerged approximately 200 thousand years ago (ka) among earlier representatives of H. sapiens or evolved gradually over the last 400 thousand years. Here we report newly discovered human fossils from Jebel Irhoud, Morocco, and interpret the affinities of the hominins from this site with other archaic and recent human groups. We identified a mosaic of features including facial, mandibular and dental morphology that aligns the Jebel Irhoud material with early or recent anatomically modern humans and more primitive neurocranial and endocranial morphology. In combination with an age of 315 ± 34 thousand years (as determined by thermoluminescence dating), this evidence makes Jebel Irhoud the oldest and richest African Middle Stone Age hominin site that documents early stages of the H. sapiens clade in which key features of modern morphology were established. Furthermore, it shows that the evolutionary processes behind the emergence of H. sapiens involved the whole African continent.

Terrestrial origin of viviparity in mesozoic marine reptiles indicated by early triassic embryonic fossils.

Directory of Open Access Journals (Sweden)

Ryosuke Motani

Full Text Available Viviparity in Mesozoic marine reptiles has traditionally been considered an aquatic adaptation. We report a new fossil specimen that strongly contradicts this traditional interpretation. The new specimen contains the oldest fossil embryos of Mesozoic marine reptile that are about 10 million years older than previous such records. The fossil belongs to Chaohusaurus (Reptilia, Ichthyopterygia, which is the oldest of Mesozoic marine reptiles (ca. 248 million years ago, Early Triassic. This exceptional specimen captures an articulated embryo in birth position, with its skull just emerged from the maternal pelvis. Its headfirst birth posture, which is unlikely to be a breech condition, strongly indicates a terrestrial origin of viviparity, in contrast to the traditional view. The tail-first birth posture in derived ichthyopterygians, convergent with the conditions in whales and sea cows, therefore is a secondary feature. The unequivocally marine origin of viviparity is so far not known among amniotes, a subset of vertebrate animals comprising mammals and reptiles, including birds. Therefore, obligate marine amniotes appear to have evolved almost exclusively from viviparous land ancestors. Viviparous land reptiles most likely appeared much earlier than currently thought, at least as early as the recovery phase from the end-Permian mass extinction.

Finding fossils in new ways: an artificial neural network approach to predicting the location of productive fossil localities.

Science.gov (United States)

Anemone, Robert; Emerson, Charles; Conroy, Glenn

2011-01-01

Chance and serendipity have long played a role in the location of productive fossil localities by vertebrate paleontologists and paleoanthropologists. We offer an alternative approach, informed by methods borrowed from the geographic information sciences and using recent advances in computer science, to more efficiently predict where fossil localities might be found. Our model uses an artificial neural network (ANN) that is trained to recognize the spectral characteristics of known productive localities and other land cover classes, such as forest, wetlands, and scrubland, within a study area based on the analysis of remotely sensed (RS) imagery. Using these spectral signatures, the model then classifies other pixels throughout the study area. The results of the neural network classification can be examined and further manipulated within a geographic information systems (GIS) software package. While we have developed and tested this model on fossil mammal localities in deposits of Paleocene and Eocene age in the Great Divide Basin of southwestern Wyoming, a similar analytical approach can be easily applied to fossil-bearing sedimentary deposits of any age in any part of the world. We suggest that new analytical tools and methods of the geographic sciences, including remote sensing and geographic information systems, are poised to greatly enrich paleoanthropological investigations, and that these new methods should be embraced by field workers in the search for, and geospatial analysis of, fossil primates and hominins. Copyright © 2011 Wiley-Liss, Inc.

Energy properties of solid fossil fuels and solid biofuels

International Nuclear Information System (INIS)

Holubcik, Michal; Jandacka, Jozef; Kolkova, Zuzana

2016-01-01

The paper deals about the problematic of energy properties of solid biofuels in comparison with solid fossil fuels. Biofuels are alternative to fossil fuels and their properties are very similar. During the experiments were done in detail experiments to obtain various properties of spruce wood pellets and wheat straw pellets like biofuels in comparison with brown coal and black coal like fossil fuels. There were tested moisture content, volatile content, fixed carbon content, ash content, elementary analysis (C, H, N, S content) and ash fusion temperatures. The results show that biofuels have some advantages and also disadvantages in comparison with solid fossil fuels.

The strategic value of fossil fuels: challenges and responses

International Nuclear Information System (INIS)

1996-01-01

Several speeches of the conference concerning the strategic value of fossil fuels that was held on May 8 to 11, 1995 in Houston, Texas are presented. The current and future importance of fossil fuels in energy consumption throughout the world is highlighted. The role of developing countries in the fossil fuels market is increasing, and these countries need some assistance from developed countries to develop. International and regional cooperation seems to be a good way to ensure economic growth. The importance of fossil fuels is shown by the growth of international coal and natural gas trade. (TEC)

Energy properties of solid fossil fuels and solid biofuels

Energy Technology Data Exchange (ETDEWEB)

Holubcik, Michal, E-mail: michal.holubcik@fstroj.uniza.sk; Jandacka, Jozef, E-mail: jozef.jandacka@fstroj.uniza.sk [University of Žilina, Faculty of Mechanical Engineering, Department of Power Engineering, Univerzitná 8215/1, 010 26 Žilina (Slovakia); Kolkova, Zuzana, E-mail: zuzana.kolkova@rc.uniza.sk [Research centre, University of Žilina, Univerzitna 8215/1, 010 26 Žilina (Slovakia)

2016-06-30

The paper deals about the problematic of energy properties of solid biofuels in comparison with solid fossil fuels. Biofuels are alternative to fossil fuels and their properties are very similar. During the experiments were done in detail experiments to obtain various properties of spruce wood pellets and wheat straw pellets like biofuels in comparison with brown coal and black coal like fossil fuels. There were tested moisture content, volatile content, fixed carbon content, ash content, elementary analysis (C, H, N, S content) and ash fusion temperatures. The results show that biofuels have some advantages and also disadvantages in comparison with solid fossil fuels.

Microelements in fossil bones and the estimation of age

International Nuclear Information System (INIS)

Besliu, C.; Olariu, A.; Popescu, I.; Badica, Th.

1993-01-01

Neutron activation analysis was used to determine microelements fossil bones and the correlation was found between some elements and the C-14 estimated age of the bones. Fluorine, uranium and manganese content in the bones structure increases with the time elapsed, during fossilization. This means that measurable concentrations of these elements and known environmental conditions could provide a relative dating tool of bones beyond the 70 ky radiocarbon limit, for paleolithic archaeology. Sodium, scandium, iron, and zinc have been also determined in fossil bones, but a relation with the increasing antiquity of the fossil has been observed. (Author)

Global exergetic dimension of hydrogen use in reducing fossil fuel consumption

International Nuclear Information System (INIS)

Adnan Midilli; Ibrahim Dincer

2009-01-01

In this paper, hydrogen is considered as a renewable and sustainable solution for minimizing the fossil fuel based-global irreversibility coefficient of global fossil fuel consumption and combating global warming and studied exergetically through a parametric performance analysis. The environmental impact results are then compared with the ones obtained for fossil fuels. In this regard, some exergetic expressions such as global waste exergy factor, global irreversibility coefficient and hydrogen based-global exergetic indicator. In order to investigate the role of hydrogen use at minimizing the fossil fuel based global irreversibility, the actual fossil fuel consumption data are taken from the literature. Due to the unavailability of appropriate hydrogen data for analysis, it is assumed that the utilization ratios of hydrogen are ranged between 0 and 1. Consequently, if exergetic utilization ratio of hydrogen from non-fossil fuel sources at a certain exergetic utilization ratio of fossil fuels increases, the fossil fuel based-global irreversibility coefficient will decrease. (author)

Phylogenetic analysis of molecular and morphological data highlights uncertainty in the relationships of fossil and living species of Elopomorpha (Actinopterygii: Teleostei).

Science.gov (United States)

Dornburg, Alex; Friedman, Matt; Near, Thomas J

2015-08-01

Elopomorpha is one of the three main clades of living teleost fishes and includes a range of disparate lineages including eels, tarpons, bonefishes, and halosaurs. Elopomorphs were among the first groups of fishes investigated using Hennigian phylogenetic methods and continue to be the object of intense phylogenetic scrutiny due to their economic significance, diversity, and crucial evolutionary status as the sister group of all other teleosts. While portions of the phylogenetic backbone for Elopomorpha are consistent between studies, the relationships among Albula, Pterothrissus, Notacanthiformes, and Anguilliformes remain contentious and difficult to evaluate. This lack of phylogenetic resolution is problematic as fossil lineages are often described and placed taxonomically based on an assumed sister group relationship between Albula and Pterothrissus. In addition, phylogenetic studies using morphological data that sample elopomorph fossil lineages often do not include notacanthiform or anguilliform lineages, potentially introducing a bias toward interpreting fossils as members of the common stem of Pterothrissus and Albula. Here we provide a phylogenetic analysis of DNA sequences sampled from multiple nuclear genes that include representative taxa from Albula, Pterothrissus, Notacanthiformes and Anguilliformes. We integrate our molecular dataset with a morphological character matrix that spans both living and fossil elopomorph lineages. Our results reveal substantial uncertainty in the placement of Pterothrissus as well as all sampled fossil lineages, questioning the stability of the taxonomy of fossil Elopomorpha. However, despite topological uncertainty, our integration of fossil lineages into a Bayesian time calibrated framework provides divergence time estimates for the clade that are consistent with previously published age estimates based on the elopomorph fossil record and molecular estimates resulting from traditional node-dating methods. Copyright �

Comparative evaluation of solar, fission, fusion, and fossil energy resources. Part 4: Energy from fossil fuels

Science.gov (United States)

Williams, J. R.

1974-01-01

The conversion of fossil-fired power plants now burning oil or gas to burn coal is discussed along with the relaxation of air quality standards and the development of coal gasification processes to insure a continued supply of gas from coal. The location of oil fields, refining areas, natural gas fields, and pipelines in the U.S. is shown. The technologies of modern fossil-fired boilers and gas turbines are defined along with the new technologies of fluid-bed boilers and MHD generators.

The first fossil cyphophthalmid harvestman from Baltic amber

Directory of Open Access Journals (Sweden)

Dunlop, Jason A.

2011-01-01

Full Text Available The first fossil cyphophthalmid harvestman (Opiliones: Cyphophthalmi from Palaeogene (Eocene Baltic amber is described. This is only the third fossil example of this basal harvestman lineage; the others being from the probably slightly younger Bitterfeld amber and the much older, early Cretaceous, Myanmar (Burmese amber. Although incomplete and lacking most of the appendages, the new Baltic amber fossil can be identified as a female. The somatic characters preserved, especially spiracle morphology and the coxo-genital region, allow it to be assigned with some confidence to the extant genus Siro Latreille, 1796 (Sironidae. This fossil is formally described here as Siro balticus sp. nov. It resembles modern North American Siro species more than modern European ones, and can be distinguished principally on its relatively large size and the outline form of the body.

Magnetohydrodynamic dynamos in the presence of fossil magnetic fields

International Nuclear Information System (INIS)

Boyer, D.W.

1982-01-01

A fossil magnetic field embedded in the radiative core of the Sun has been thought possible for some time now. However, such a fossil magnetic field has, a priori, not been considered a visible phenomenon due to the effects of turbulence in the solar convection zone. Since a well developed theory (referred to herein as magnetohydrodynamic dynamo theory) exists for describing the regeneration of magnetic fields in astrophysical objects like the Sun, it is possible to quantitatively evaluate the interaction of a fossil magnetic field with the magnetohydrodynamic dynamo operating in the solar convection zone. In this work, after a brief description of the basic dynamo equations, a spherical model calculation of the solar dynamo is introduced. First, the interaction of a fossil magnetic field with a dynamo in which the regeneration mechanisms of cyclonic convection and large-scale, nonuniform rotation are confined to spherical shells is calculated. It is argued that the amount of amplification or suppression of a fossil magnetic field will be smallest for a uniform distribution of cyclonic convection and nonuniform rotation, as expected in the Sun. Secondly, the interaction of a fossil magnetic field with a dynamo having a uniform distribution of cyclonic convection and large-scale, nonuniform rotation is calculated. It is found that the dipole or quadrupole moments of a fossil magnetic field are suppressed by factors of -0.35 and -0.37, respectively

Danmarks Største Fossiler

DEFF Research Database (Denmark)

Lindow, Bent Erik Kramer; Cuny, Gilles Guy Roger

2008-01-01

For 8 millioner år siden myldrede Nordsøen af en mangfoldighed af hajer, hvaler, havskildpadder og sæler, mange flere end i dag. Blandt dem finder man Danmarks største fossiler som er udstillet på Museum Sønderjylland - Naturhistorie og Palæontologi i Gram.......For 8 millioner år siden myldrede Nordsøen af en mangfoldighed af hajer, hvaler, havskildpadder og sæler, mange flere end i dag. Blandt dem finder man Danmarks største fossiler som er udstillet på Museum Sønderjylland - Naturhistorie og Palæontologi i Gram....

Into Tibet: An Early Pliocene Dispersal of Fossil Zokor (Rodentia: Spalacidae) from Mongolian Plateau to the Hinterland of Tibetan Plateau.

Science.gov (United States)

Li, Qiang; Wang, Xiaoming

2015-01-01

This paper reports the fossil zokors (Myospalacinae) collected from the lower Pliocene (~4.4 Ma) of Zanda Basin, southwestern Tibet, which is the first record in the hinterland of Tibetan Plateau within the Himalayan Range. Materials include 29 isolated molars belonging to Prosiphneus eriksoni (Schlosser, 1924) by having characters including large size, highly fused roots, upper molars of orthomegodont type, m1 anterior cap small and centrally located, and first pair of m1 reentrants on opposing sides, high crowns, and high value of dentine tract parameters. Based on the cladistics analysis, all seven species of Prosiphneus and P. eriksoni of Zanda form a monophyletic clade. P. eriksoni from Zanda, on the other hand, is nearly the terminal taxon of this clade. The appearance of P. eriksoni in Zanda represents a significant dispersal in the early Pliocene from its center of origin in north China and Mongolian Plateau, possibly via the Hol Xil-Qiangtang hinterland in northern Tibet. The fast evolving zokors are highly adapted to open terrains at a time when regional climates had become increasingly drier in the desert zones north of Tibetan Plateau during the late Miocene to Pliocene. The occurrence of this zokor in Tibet thus suggests a rather open steppe environment. Based on fossils of large mammals, we have formulated an "out of Tibet" hypothesis that suggests earlier and more primitive large mammals from the Pliocene of Tibet giving rise to the Ice Age megafauna. However, fossil records for large mammals are still too poor to evaluate whether they have evolved from lineages endemic to the Tibetan Plateau or were immigrants from outside. The superior record of small mammals is in a better position to address this question. With relatively dense age intervals and numerous localities in much of northern Asia, fossil zokors provide the first example of an "into Tibet" scenario--earlier and more primitive taxa originated from outside of the Tibetan Plateau and the

Proceedings of the sixth annual conference on fossil energy materials. Fossil Energy AR and TD Mateials Program

Energy Technology Data Exchange (ETDEWEB)

Cole, N.C.; Judkins, R.R. [comps.

1992-07-01

The Sixth Annual Conference on Fossil Energy Materials was held in Oak Ridge, Tennessee, on May 12--14, 1992. The meeting was sponsored by the US Department of Energy`s Office of Fossil Energy through the Advanced Research and Technology Development (AR&TD) Materials Program, and ASM International. The objective of the AR&TD Materials Program is to conduct research and development on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. The management of the Program has been decentralized to the DOE Field Office, Oak Ridge with Oak Ridge National Laboratory (ORNL) as the technical support contractor. The research is performed by staff members at ORNL and by a substantial number of researchers at other national laboratories, universities, and in private industry. The work is divided into the following categories: (1) ceramics, (2) development and corrosion resistance of iron aluminide, advanced austenitic and chromium-niobium alloys, and (3) technology assessment and technology transfer. This conference is held each year to review the work on all of the projects of the Program. The agenda for the meeting is given in Appendix A, and a list of attendees is presented in Appendix B. ASM International cosponsored the conference, for which we are especially grateful.

China's INDC and non-fossil energy development

Directory of Open Access Journals (Sweden)

Jian-Kun He

2015-09-01

Full Text Available Global climate change promotes the energy system reform. Achieving a high proportion of renewable energy becomes the major countries' energy strategy. As proposed in its Intended Nationally Determined Contributions (INDC, China intends to raise the proportion of non-fossil energy in primary energy consumption to about 20% by 2030. That ambitious goal means the non-fossil energy supplies by 2030 will be 7–8 times that of 2005, and the annual increase rate is more than 8% within the 25 years. Besides, the capacity of wind power, solar power, hydropower and nuclear power reaches 400 GW, 350 GW, 450 GW, and 150 GW respectively, and China's non-fossil power capacity is even greater than the U.S.'s total power capacity. In addition, the scale of natural gas increases. Consequently, by 2030, the proportion of coal falls from the current 70% to below 50%, and the CO2 intensity of energy consumption decreases by 20% compared with the level of 2005, which play important roles in significantly reducing the CO2 intensity of GDP. Since China has confirmed to achieve the CO2 emissions peak around 2030, at that time, the newly added energy demand will be satisfied by non-fossil energy, and the consumption of fossil fuel will stop growing. By 2030, non-fossil energy accounts for 20%, and the large scale and sound momentum of new and renewable energy industry will support the growth of total energy demand, which plays a key role in CO2 emissions peaking and beginning to decline, and lays the foundation for establishing a new energy system dominated by new and renewable energy in the second half of the 21st century as well as finally achieving the CO2 zero-emission.

100 years of discovery of the Burgess Shale 1909-2009 : a celebration of the discovery of the world's most important fossils

International Nuclear Information System (INIS)

2009-01-01

The centennial celebration of the discovery of the Burgess Shale consisted of informative science presentations to the general public. Scientific presenters also participated in guided hikes in Yoho National Park within the Canadian Rockies where the Burgess Shale can be found. The first Burgess Shale fossils were discovered in 1909 by Charles D. Walcott. Thousands of specimens have since been collected from the quarry named after him. The informative science presentations described the burst of biodiversity of marine plants and marine invertebrate animals that lived in a shallow sea in the vicinity of a massive carbonate reef during the Cambrian Period. They described the unusual conditions that allowed for the very rare preservation of the animals in the Burgess Shale. The Burgess Shale fossils merit special interest because they reveal how animal life appeared on Earth better than any other fossil record. In addition to the geological history of the Burgess Shale area, the centennial lectures also addressed topics such as climate and the geological record of climate change; the influence of continental drift on evolution; and fluid geochemistry in the Western Canada Foreland Basin and paleoclimate influence. The Burgess Shale was designated a UNESCO World Heritage Site in 1981 as it provides key information about evolution of life on Earth. refs. figs

Fossil Energy Advanced Research and Technology Development (AR&TD) Materials Program semiannual progress report for the period ending September 30, 1991. Fossil Energy Program

Energy Technology Data Exchange (ETDEWEB)

Judkins, R.R.; Cole, N.C. [comps.

1992-04-01

The objective of the Fossil Energy Advanced Research and Technology Development Materials Program is to conduct research and development on materials for fossil energy applications with a focus on the longer-term and generic needs of the various fossil fuel technologies. The Program includes research aimed toward a better understanding of materials behavior in fossil energy environments and the development of new materials capable of substantial enhancement of plant operations and reliability. Research is outlined in four areas: Ceramics, New Alloys, Corrosion and Erosion Research, and Technology Development and Transfer. (VC)

Implications for global energy markets: implications for non-fossil energy sources

International Nuclear Information System (INIS)

Grubb, Michael

1998-01-01

This paper highlights the recent developments concerning non-fossil energy and examines the impact of the Kyoto Protocol on non-fossil energy sources, and the implications for non-fossil sources in the implementation of the Kyoto Protocol. The current contributions of fossil and non-fossil fuels to electricity production, prospects for expansion of the established non-fossil sources, new renewables in Europe to date, renewables in Europe to 2010, and policy integration in the EU are discussed. Charts illustrating the generating capacity of renewable energy plant in Britain (1992-1966), wind energy capacity in Europe (1990-2000), and projected renewable energy contributions in the EU (wind, small hydro, photovoltaic, biomass and geothermal) are provided. (UK)

The rise of fire: Fossil charcoal in late Devonian marine shales as an indicator of expanding terrestrial ecosystems, fire, and atmospheric change

Science.gov (United States)

Rimmer, Susan M.; Hawkins, Sarah J.; Scott, Andrew C.; Cressler, Walter L.

2015-01-01

Fossil charcoal provides direct evidence for fire events that, in turn, have implications for the evolution of both terrestrial ecosystems and the atmosphere. Most of the ancient charcoal record is known from terrestrial or nearshore environments and indicates the earliest occurrences of fire in the Late Silurian. However, despite the rise in available fuel through the Devonian as vascular land plants became larger and trees and forests evolved, charcoal occurrences are very sparse until the Early Mississippian where extensive charcoal suggests well-established fire systems. We present data from the latest Devonian and Early Mississippian of North America from terrestrial and marine rocks indicating that fire became more widespread and significant at this time. This increase may be a function of rising O2 levels and the occurrence of fire itself may have contributed to this rise through positive feedback. Recent atmospheric modeling suggests an O2 low during the Middle Devonian (around 17.5%), with O2 rising steadily through the Late Devonian and Early Mississippian (to 21–22%) that allowed for widespread burning for the first time. In Devonian-Mississippian marine black shales, fossil charcoal (inertinite) steadily increases up-section suggesting the rise of widespread fire systems. There is a concomitant increase in the amount of vitrinite (preserved woody and other plant tissues) that also suggests increased sources of terrestrial organic matter. Even as end Devonian glaciation was experienced, fossil charcoal continued to be a source of organic matter being introduced into the Devonian oceans. Scanning electron and reflectance microscopy of charcoal from Late Devonian terrestrial sites indicate that the fires were moderately hot (typically 500–600 °C) and burnt mainly surface vegetation dominated by herbaceous zygopterid ferns and lycopsids, rather than being produced by forest crown fires. The occurrence and relative abundance of fossil charcoal in

The energy challenge of a post-fossil world: Seasonal energy storage

International Nuclear Information System (INIS)

Forsberg, C.

2009-01-01

Fossil fuels are an energy source and an energy storage system. The demand for electricity and heat varies daily, weekly, and seasonally with seasonal variations often varying by a factor of two or more. The variable demand is met by fossil fuels because 1) fossil fuels are inexpensive to store in coal piles, oil tanks, and underground natural gas storage facilities and 2) the capital cost of the equipment to burn fossil fuels and convert the energy to heat or electricity is small relative to the cost of the fossil fuels. Concerns about climate change may limit the conventional use of fossil fuels. The alternative low-carbon energy production systems (nuclear, fossil fuels with carbon dioxide sequestration, wind, and solar) are capital-intensive energy sources with low operating costs. To obtain favorable economics these technologies must operate at full capacity; but, their output does not match energy demand. We have energy alternatives to fossil fuels but no replacements for the energy storage capabilities or fossil fuels. Proposed strategies and technologies to address the grand storage challenge (including seasonal storage of electricity) are described. The options suggest a nuclear-renewable future to address seasonal energy storage needs in a low-carbon world.

When will fossil fuel reserves be diminished?

International Nuclear Information System (INIS)

Shafiee, Shahriar; Topal, Erkan

2009-01-01

Crude oil, coal and gas are the main resources for world energy supply. The size of fossil fuel reserves and the dilemma that 'when non-renewable energy will be diminished' is a fundamental and doubtful question that needs to be answered. This paper presents a new formula for calculating when fossil fuel reserves are likely to be depleted and develops an econometrics model to demonstrate the relationship between fossil fuel reserves and some main variables. The new formula is modified from the Klass model and thus assumes a continuous compound rate and computes fossil fuel reserve depletion times for oil, coal and gas of approximately 35, 107 and 37 years, respectively. This means that coal reserves are available up to 2112, and will be the only fossil fuel remaining after 2042. In the Econometrics model, the main exogenous variables affecting oil, coal and gas reserve trends are their consumption and respective prices between 1980 and 2006. The models for oil and gas reserves unexpectedly show a positive and significant relationship with consumption, while presenting a negative and significant relationship with price. The econometrics model for coal reserves, however, expectedly illustrates a negative and significant relationship with consumption and a positive and significant relationship with price. Consequently, huge reserves of coal and low-level coal prices in comparison to oil and gas make coal one of the main energy substitutions for oil and gas in the future, under the assumption of coal as a clean energy source

Paleo-Antarctic rainforest into the modern Old World tropics: the rich past and threatened future of the "southern wet forest survivors".

Science.gov (United States)

Kooyman, Robert M; Wilf, Peter; Barreda, Viviana D; Carpenter, Raymond J; Jordan, Gregory J; Sniderman, J M Kale; Allen, Andrew; Brodribb, Timothy J; Crayn, Darren; Feild, Taylor S; Laffan, Shawn W; Lusk, Christopher H; Rossetto, Maurizio; Weston, Peter H

2014-12-01

• Have Gondwanan rainforest floral associations survived? Where do they occur today? Have they survived continuously in particular locations? How significant is their living floristic signal? We revisit these classic questions in light of significant recent increases in relevant paleobotanical data.• We traced the extinction and persistence of lineages and associations through the past across four now separated regions-Australia, New Zealand, Patagonia, and Antarctica-using fossil occurrence data from 63 well-dated Gondwanan rainforest sites and 396 constituent taxa. Fossil sites were allocated to four age groups: Cretaceous, Paleocene-Eocene, Neogene plus Oligocene, and Pleistocene. We compared the modern and ancient distributions of lineages represented in the fossil record to see if dissimilarity increased with time. We quantified similarity-dissimilarity of composition and taxonomic structure among fossil assemblages, and between fossil and modern assemblages.• Strong similarities between ancient Patagonia and Australia confirmed shared Gondwanan rainforest history, but more of the lineages persisted in Australia. Samples of ancient Australia grouped with the extant floras of Australia, New Guinea, New Caledonia, Fiji, and Mt. Kinabalu. Decreasing similarity through time among the regional floras of Antarctica, Patagonia, New Zealand, and southern Australia reflects multiple extinction events.• Gondwanan rainforest lineages contribute significantly to modern rainforest community assembly and often co-occur in widely separated assemblages far from their early fossil records. Understanding how and where lineages from ancient Gondwanan assemblages co-occur today has implications for the conservation of global rainforest vegetation, including in the Old World tropics. © 2014 Botanical Society of America, Inc.

Fossil struthionid eggshells from Laetoli, Tanzania: Taxonomic and biostratigraphic significance

Science.gov (United States)

Harrison, Terry; Msuya, Charles P.

2005-04-01

Recent paleontological investigations at Laetoli and neighboring localities in northern Tanzania have produced a large collection of fossil ostrich eggshells from the Pliocene-aged Laetolil Beds (˜3.5-4.5 Ma) and Ndolanya Beds (˜2.6-2.7 Ma). A detailed analysis of the morphology of the eggshells and their taxonomic affinities indicates that two different species of Struthio are represented. In the Lower Laetolil Beds and in the Upper Laetolil Beds below Tuff 3 a new species is recognized— Struthio kakesiensis. This is replaced in the Upper Laetolil Beds by Struthio camelus, the modern species of ostrich. Since radiometric age determinations are available for the stratigraphic sequence at Laetoli, it is possible to precisely date the first appearance of S. camelus at ˜3.6-3.8 Ma. Comparisons of the Laetoli material with specimens from the well-dated sequences at Lothagam and Kanapoi in northern Kenya, allow the taxonomic and biochronological analysis to be extended back in time to the late Miocene. At about 6.5 Ma, Diamantornis and elephant birds were replaced in East Africa by ostriches belonging to the genus Struthio. Three time-successive species of ostriches are identified in the fossil record of East Africa, beginning with Struthio. cf. karingarabensis (˜6.5-4.2 Ma), followed by S. kakesiensis (˜4.5-3.6 Ma) and then S. camelus (˜3.8 Ma onwards). A similar sequence of taxa has previously been recorded from localities in Namibia, but at these sites there is no possibility to precisely calibrate the ages of the different species using radiometric dating. Nevertheless, the broadly similar evolutionary sequence and the close correspondence in inferred ages for the succession of species in East Africa and Namibia suggest that ostrich eggshells are a very useful tool for biochronological correlation of paleontological sites in sub-Saharan Africa.

Atmospheric observations of carbon monoxide and fossil fuel CO2 emissions from East Asia

DEFF Research Database (Denmark)

Turnbull, Jocelyn C.; Tans, Pieter P.; Lehman, Scott J.

2011-01-01

Flask samples from two sites in East Asia, Tae-Ahn Peninsula, Korea (TAP), and Shangdianzi, China (SDZ), were measured for trace gases including CO2, CO and fossil fuel CO2(CO(2)ff, derived from Delta(CO2)-C-14 observations). The five-year TAP record shows high CO(2)ff when local air comes from...... the Korean Peninsula. Most samples, however, reflect air masses from Northeastern China with lower CO(2)ff. Our small set of SDZ samples from winter 2009/2010 have strongly elevated CO(2)ff. Biospheric CO2 contributes substantially to total CO2 variability at both sites, even in winter when non-fossil CO2....../ppm respectively, consistent with recent bottom-up inventory estimates and other observational studies. Locally influenced TAP samples fall into two distinct data sets, ascribed to air sourced from South Korea and North Korea. The South Korea samples have low R-CO:CO2ff of 13 +/- 3 ppb/ppm, slightly higher than...

A long-term view of worldwide fossil fuel prices

International Nuclear Information System (INIS)

Shafiee, Shahriar; Topal, Erkan

2010-01-01

This paper reviews a long-term trend of worldwide fossil fuel prices in the future by introducing a new method to forecast oil, natural gas and coal prices. The first section of this study analyses the global fossil fuel market and the historical trend of real and nominal fossil fuel prices from 1950 to 2008. Historical fossil fuel price analysis shows that coal prices are decreasing, while natural gas prices are increasing. The second section reviews previously available price modelling techniques and proposes a new comprehensive version of the long-term trend reverting jump and dip diffusion model. The third section uses the new model to forecast fossil fuel prices in nominal and real terms from 2009 to 2018. The new model follows the extrapolation of the historical sinusoidal trend of nominal and real fossil fuel prices. The historical trends show an increase in nominal/real oil and natural gas prices plus nominal coal prices, as well as a decrease in real coal prices. Furthermore, the new model forecasts that oil, natural gas and coal will stay in jump for the next couple of years and after that they will revert back to the long-term trend until 2018. (author)

Depletion of fossil fuels and anthropogenic climate change—A review

International Nuclear Information System (INIS)

Höök, Mikael; Tang, Xu

2013-01-01

Future scenarios with significant anthropogenic climate change also display large increases in world production of fossil fuels, the principal CO 2 emission source. Meanwhile, fossil fuel depletion has also been identified as a future challenge. This chapter reviews the connection between these two issues and concludes that limits to availability of fossil fuels will set a limit for mankind's ability to affect the climate. However, this limit is unclear as various studies have reached quite different conclusions regarding future atmospheric CO 2 concentrations caused by fossil fuel limitations. It is concluded that the current set of emission scenarios used by the IPCC and others is perforated by optimistic expectations on future fossil fuel production that are improbable or even unrealistic. The current situation, where climate models largely rely on emission scenarios detached from the reality of supply and its inherent problems are problematic. In fact, it may even mislead planners and politicians into making decisions that mitigate one problem but make the other one worse. It is important to understand that the fossil energy problem and the anthropogenic climate change problem are tightly connected and need to be treated as two interwoven challenges necessitating a holistic solution. - Highlights: ► Review of the development of emission scenarios. ► Survey of future fossil fuel trajectories used by the IPCC emission scenarios. ► Discussions on energy transitions in the light of oil depletion. ► Review of earlier studies of future climate change and fossil fuel limitations.

Study of fossil wood from the Middle-Late Miocene sediments of Dhemaji and Lakhimpur districts of Assam, India and its palaeoecological and palaeophytogeographical implications

Science.gov (United States)

Mehrotra, R. C.; Bera, S. K.; Basumatary, S. K.; Srivastava, G.

2011-08-01

In order to reconstruct the palaeoclimate, a number of fossil wood pieces were collected and investigated from two new fossil localities situated in the Dhemaji and Lakhimpur districts of Assam. They belong to the Tipam Group considered to be of Middle-Late Miocene in age and show affinities with Gluta (Anacardiaceae), Bischofia (Euphorbiaceae), Bauhinia, Cynometra, Copaifera-Detarium-Sindora, Millettia-Pongamia, and Afzelia-Intsia (Fabaceae). The flora also records a new species of Bauhinia named Bauhinia miocenica sp. nov. The assemblage indicates a warm and humid climate in the region during the deposition of the sediments. The occurrence of some southeast Asian elements in the fossil flora indicates that an exchange of floral elements took place between India and southeast Asia during the Miocene.

Renewables vs fossil fuels

Energy Technology Data Exchange (ETDEWEB)

Adams, K. (Energy Research and Development Corporation (Australia))

1992-01-01

The paper examines some of the factors which will influence the future mix of energy from fossil fuels and renewable sources in Australia. Aspects covered include: the present energy situation; impact of environmental issues; potential for renewable energy; motivators for change; and research and development. It is concluded that the future for fossil fuels and renewable energy is dependent on a number of complex factors, many of which are currently unknown. The key factor is economic viability and that will be influenced by a range of factors such as policies of the Australian and overseas governments in relation to pollution and environment protection (reflected in the cost of meeting such requirements), exploration and production costs (also influenced by government policies), availability of supply, rate of technological development and the size of export markets. 8 refs., 2 figs., 1 tab.

A compendium of fossil marine animal families, 2nd edition

Science.gov (United States)

Sepkoski, J. J. Jr; Sepkoski JJ, J. r. (Principal Investigator)

1992-01-01

A comprehensive listing of 4075 taxonomic families of marine animals known from the fossil record is presented. This listing covers invertebrates, vertebrates, and animal-like protists, gives time intervals of apparent origination and extinction, and provides literature sources for these data. The time intervals are mostly 81 internationally recognized stratigraphic stages; more than half of the data are resolved to one of 145 substage divisions, providing more highly resolved data for studies of taxic macroevolution. Families are classified by order, class, and phylum, reflecting current classifications in the published literature. This compendium is a new edition of the 1982 publication, correcting errors and presenting greater stratigraphic resolution and more current ideas about acceptable families and their classification.

The financial impact of divestment from fossil fuels

NARCIS (Netherlands)

Plantinga, Auke; Scholtens, Bert

2016-01-01

Divesting from fossil companies has been put forward as a means to address climate change. We study the impact of such divesting on investment portfolio performance. To this extent, we systematically investigate the investment performance of portfolios with and without fossil fuel company stocks. We

Methane emissions and climate compatibility of fossil fuels

International Nuclear Information System (INIS)

Meier, B.

1992-01-01

Methane contributes directly and indirectly to the additional greenhouse effect caused by human activities. The vast majority of the anthropogenic methane release occurs worldwide in non-fossil sources such as rice cultivation, livestock operations, sanitary landfills and combustion of bio-mass. Methane emissions also occur during production, distribution and utilisation of fossil fuels. Also when considering the methane release and CO 2 -emissions of processes upstream of combustion, the ranking of environmental compatibility of natural gas, fuel oil and cool remains unchanged. Of all fossil fuels, natural gas contributes the least to the greenhouse effect. (orig.) [de

Problems related to fossil fuels utilization

International Nuclear Information System (INIS)

Rota, R.

1999-01-01

Fossil fuels still present the main energy source in the world since about 90% of the energy produced comes from combustion. This paper, based on the lectures given at the conference of Energy and Environment hold at the Accademia dei Lincei in 1998, presents a short review of some of the problems related to the utilization of fossil fuels, such as their availability in the medium period, the effect of pollutant dispersion in the atmosphere as well as the available technologies to deal with such problems [it

The occurrence of an abdominal fauna in an articulated tapir (Tapirus polkensis) from the Late Miocene Gray Fossil Site, Northeastern Tennessee.

Science.gov (United States)

McCONNELL, Shannon M; Zavada, Michael S

2013-03-01

The analysis of samples recovered from the abdominal area of an articulated tapir (Tapirus polkensis) from the Late Miocene (4.5-7 million BP) Gray Fossil Site (GFS) revealed a rich palyno-fauna comprised of about 94% egg/oocyst-like structures and 6% pollen and other palynomorphs. In addition, a group of 6 hickory nuts (Carya) was recovered from the same area suggesting that the samples represent the abdominal contents. The analysis of a sample from immediately outside the tapir produced a sample with 98% pollen and less than 0.5% egg/oocyst-like structures. The size, shape, and general morphology of egg/oocyst-like structures were analyzed with light and scanning electron microscopy and were compared to a variety of intestinal parasites found in extant ungulates, and the Perissodactyla in particular. We also compared fossil structures to the numbers and kind of intestinal parasites recovered from fecal samples from the Baird's tapir (T. bairdii) in Costa Rica and from samples collected from the lowland tapir (T. terrestris) from Ecuador to assess their similarity to our fossil sample. Based on these data, we discuss what role parasites may have played in the biology of T. polkensis during the Late Miocene-Early Pliocene. © 2012 Wiley Publishing Asia Pty Ltd, ISZS and IOZ/CAS.

Hydrogen as a renewable and sustainable solution in reducing global fossil fuel consumption

International Nuclear Information System (INIS)

Midilli, Adnan; Dincer, Ibrahim

2008-01-01

In this paper, hydrogen is considered as a renewable and sustainable solution for reducing global fossil fuel consumption and combating global warming and studied exergetically through a parametric performance analysis. The environmental impact results are then compared with the ones obtained for fossil fuels. In this regard, some exergetic expressions are derived depending primarily upon the exergetic utilization ratios of fossil fuels and hydrogen: the fossil fuel based global waste exergy factor, hydrogen based global exergetic efficiency, fossil fuel based global irreversibility coefficient and hydrogen based global exergetic indicator. These relations incorporate predicted exergetic utilization ratios for hydrogen energy from non-fossil fuel resources such as water, etc., and are used to investigate whether or not exergetic utilization of hydrogen can significantly reduce the fossil fuel based global irreversibility coefficient (ranging from 1 to +∞) indicating the fossil fuel consumption and contribute to increase the hydrogen based global exergetic indicator (ranging from 0 to 1) indicating the hydrogen utilization at a certain ratio of fossil fuel utilization. In order to verify all these exergetic expressions, the actual fossil fuel consumption and production data are taken from the literature. Due to the unavailability of appropriate hydrogen data for analysis, it is assumed that the utilization ratios of hydrogen are ranged between 0 and 1. For the verification of these parameters, the variations of fossil fuel based global irreversibility coefficient and hydrogen based global exergetic indicator as the functions of fossil fuel based global waste exergy factor, hydrogen based global exergetic efficiency and exergetic utilization of hydrogen from non-fossil fuels are analyzed and discussed in detail. Consequently, if exergetic utilization ratio of hydrogen from non-fossil fuel sources at a certain exergetic utilization ratio of fossil fuels increases

Fossil-Fuel C02 Emissions Database and Exploration System

Science.gov (United States)

Krassovski, M.; Boden, T.

2012-04-01

Fossil-Fuel C02 Emissions Database and Exploration System Misha Krassovski and Tom Boden Carbon Dioxide Information Analysis Center Oak Ridge National Laboratory The Carbon Dioxide Information Analysis Center (CDIAC) at Oak Ridge National Laboratory (ORNL) quantifies the release of carbon from fossil-fuel use and cement production each year at global, regional, and national spatial scales. These estimates are vital to climate change research given the strong evidence suggesting fossil-fuel emissions are responsible for unprecedented levels of carbon dioxide (CO2) in the atmosphere. The CDIAC fossil-fuel emissions time series are based largely on annual energy statistics published for all nations by the United Nations (UN). Publications containing historical energy statistics make it possible to estimate fossil-fuel CO2 emissions back to 1751 before the Industrial Revolution. From these core fossil-fuel CO2 emission time series, CDIAC has developed a number of additional data products to satisfy modeling needs and to address other questions aimed at improving our understanding of the global carbon cycle budget. For example, CDIAC also produces a time series of gridded fossil-fuel CO2 emission estimates and isotopic (e.g., C13) emissions estimates. The gridded data are generated using the methodology described in Andres et al. (2011) and provide monthly and annual estimates for 1751-2008 at 1° latitude by 1° longitude resolution. These gridded emission estimates are being used in the latest IPCC Scientific Assessment (AR4). Isotopic estimates are possible thanks to detailed information for individual nations regarding the carbon content of select fuels (e.g., the carbon signature of natural gas from Russia). CDIAC has recently developed a relational database to house these baseline emissions estimates and associated derived products and a web-based interface to help users worldwide query these data holdings. Users can identify, explore and download desired CDIAC

Financial subsidies to the Australian fossil fuel industry

International Nuclear Information System (INIS)

Riedy, Chris; Diesendorf, Mark

2003-01-01

A common claim during international greenhouse gas reduction negotiations has been that domestic emissions cuts will harm national economies. This argument fails to consider the distorting effect of existing financial subsidies and associated incentives to fossil fuel production and consumption provided by governments in most developed countries. These subsidies support a fossil fuel energy sector that is the major contributor to global greenhouse gas emissions and conflict with attempts to expand the role of sustainable energy technologies. Reform of these types of subsidies has the potential to provide substantial gains in economic efficiency as well as reductions in carbon dioxide emissions--a 'no regrets' outcome for the economy and the environment. This paper examines financial subsidies to fossil fuel production and consumption in Australia and estimates the magnitude of the subsidies. Subsidies and associated incentives to fossil fuel production and consumption in Australia are similar to those in the United States and the other countries that have pushed for increased 'flexibility' during international negotiations

A massive hydrogen-rich Martian greenhouse recorded in D/H

Science.gov (United States)

Pahlevan, K.; Schaefer, L. K.; Desch, S. J.; Elkins-Tanton, L. T.

2017-12-01

The deuterium-to-hydrogen (D/H) ratio in Martian atmospheric water ( 6x standard mean ocean water, SMOW) [1,2] is higher than that of known sources [3,4] alluding to a planetary enrichment process. A recent measurement by the Curiosity rover of Hesperian clays yields a D/H value 3x higher than SMOW [5], demonstrating that most enrichment occurred early in planetary history, buttressing the conclusions of Martian meteorite studies [6,7]. Extant models of the isotopic evolution of the Martian hydrosphere have not incorporated primordial H2, despite its likely abundance on early Mars. Here, we report the first 1D climate calculations with an atmospheric composition determined via degassing from a reducing magma ocean to study Martian climate during an early water ocean stage. A reducing Martian magma ocean is expected based on experimental petrology [8], the degassing of which gives rise to an H2-rich steam atmosphere [9] with strong attendant greenhouse warming [10,11] even after the removal of steam via condensation. At the pressures and temperatures prevailing in such a degassed greenhouse, we find that isotopic exchange in the fluid envelope is rapid, strongly concentrating deuterium in water molecules over molecular hydrogen [12]. The subsequent loss of the isotopically light H2-rich atmosphere results in a 2x D/H enrichment in the oceans via isotopic equilibration alone. These calculations suggest that most of the D/H enrichment observed in the first billion years of Martian history is produced by the evolution of a massive ( 100 bar) H2-rich greenhouse in the aftermath of magma ocean crystallization. The proposed link between early planetary process and modern isotopic observable opens a new window into the earliest history of Mars. [1] Owen, T. et al. Science 240, 1767-1770 (1988). [2] Webster, C. R. et al. Science 341, 260-263 (2013). [3] Lunine, J. I. et al. Icarus 165, 1-8, (2003). [4] Marty, B. et al. EPSL 441, 91-102, (2016). [5] Mahaffy, P. et al

News technology utilization fossil fuel

Directory of Open Access Journals (Sweden)

Blišanová Monika

2004-09-01

Full Text Available Fossil fuel – “alternative energy“ is coal, petroleum, natural gas. Petroleum and natural gas are scarce resources, but they are delimited. Reserves petroleum will be depleted after 39 years and reserves natural gas after 60 years.World reserves coal are good for another 240 years. Coal is the most abundant fossil fuel. It is the least expensive energy source for generating electricity. Many environmental problems associated with use of coal:in coal production, mining creates environmental problems.On Slovakia representative coal only important internal fuel – power of source and coal is produced in 5 locality. Nowadays, oneself invest to new technology on utilization coal. Perspective solution onself shows UCG, IGCC.

Water Use of Fossil Energy Production and Supply in China

Directory of Open Access Journals (Sweden)

Gang Lin

2017-07-01

Full Text Available Fossil energy and water resources are both important for economic and social development in China, and they are tightly interlinked. Fossil energy production consumes large amounts of water, and it is essential to investigate the water footprint of fossil energy production (WFEP in China. In addition, fossil energy is supplied to consumers in China by both domestic and foreign producers, and understanding the water footprint of fossil energy supply (WFES is also highly significant for water and energy development programs in the long-term. The objectives of this paper were to provide an estimation of the blue component of WFEP and WFES in China for the period from 2001 to 2014, and to evaluate the impact on water resources from energy production, the contribution of internal and external WFES, and water-energy related issues of the international energy trade by applying water footprint analysis based on the bottom-up approach. The results indicate that generally, the WFEP and WFES in China both maintained steady growth before 2013, with the WFEP increasing from approximately 3900 million m3/year to 10,400 million m3/year, while the WFES grew from 3900 million m3/year to 11,600 million m3/year. The fossil energy production caps of the 13th Five Year Plan can bring the water consumed for fossil energy production back to a sustainable level. Over the long-term, China’s energy trade plan should also consider the water and energy resources of the countries from which fossil energy is imported.

Mitochondrial phylogenomics of modern and ancient equids

DEFF Research Database (Denmark)

Mouatt, Julia Thidamarth Vilstrup; Seguin-Orlando, Andaine; Stiller, Mathias

2013-01-01

The genus Equus is richly represented in the fossil record, yet our understanding of taxonomic relationships within this genus remains limited. To estimate the phylogenetic relationships among modern horses, zebras, asses and donkeys, we generated the first data set including complete mitochondrial...

Fossils and decapod phylogeny

NARCIS (Netherlands)

Schram, Frederick R.; Dixon, Christopher

2003-01-01

An expanded series of morphological characters developed for a cladistic analysis of extant decapods has yielded a new hypothesis for the phylogeny of the group. Application of this database to selected fossil genera produces some interesting results and demonstrates the feasibility of treating

Fossil resource trade balances. Emerging trends for the UK

International Nuclear Information System (INIS)

Papathanasopoulou, Eleni; Jackson, Tim

2008-01-01

The aim of this paper is to examine the extent to which the UK can be classified as a net importer of fossil resources and a creator of pollution havens abroad between 1968 and 2000. Using input-output techniques and a derived Resource Flow Classification System, both the physical trade balance (PTB) and pollution trade balance (UTB) associated with fossil resource use are computed. The PTB shows that between 1968 and the early 1980's the UK is presented as a net importer of direct fossil resource flows. Between 1984 and 2000, the UK is identified as a net exporter of direct fossil resources. These trends are primarily explained by the UK's discovery and commercial production of North Sea oil and gas fields in the late 1970s. On the other hand, the UTB shows that over the whole period the indirect used flows attributable to the UK's exports are higher than those attributable to its imports. These findings suggest that the UK did not create pollution havens abroad from the use of fossil resources between 1968 and 2000. However, it is noticeable in both cases that from 1995 the UK's position as a net exporter has been decreasing considerably. Maturing North Sea oil and gas fields set against increasing demands for fossil fuels and imported goods is signalling a return to the UK's pre-1984 dependence on direct imported fossil resources and the possible creation of pollution havens abroad. Knowledge of these trends contributes to the evidence base for the UK's changing import and export structure and the potential environmental repercussions at home and abroad. (author)

Fossil resource trade balances. Emerging trends for the UK

Energy Technology Data Exchange (ETDEWEB)

Papathanasopoulou, Eleni; Jackson, Tim [Centre for Environmental Strategy, University of Surrey, Guildford, Surrey, GU2 7TH (United Kingdom)

2008-06-15

The aim of this paper is to examine the extent to which the UK can be classified as a net importer of fossil resources and a creator of pollution havens abroad between 1968 and 2000. Using input-output techniques and a derived Resource Flow Classification System, both the physical trade balance (PTB) and pollution trade balance (UTB) associated with fossil resource use are computed. The PTB shows that between 1968 and the early 1980's the UK is presented as a net importer of direct fossil resource flows. Between 1984 and 2000, the UK is identified as a net exporter of direct fossil resources. These trends are primarily explained by the UK's discovery and commercial production of North Sea oil and gas fields in the late 1970s. On the other hand, the UTB shows that over the whole period the indirect used flows attributable to the UK's exports are higher than those attributable to its imports. These findings suggest that the UK did not create pollution havens abroad from the use of fossil resources between 1968 and 2000. However, it is noticeable in both cases that from 1995 the UK's position as a net exporter has been decreasing considerably. Maturing North Sea oil and gas fields set against increasing demands for fossil fuels and imported goods is signalling a return to the UK's pre-1984 dependence on direct imported fossil resources and the possible creation of pollution havens abroad. Knowledge of these trends contributes to the evidence base for the UK's changing import and export structure and the potential environmental repercussions at home and abroad. (author)

Historical atmospheric pollution trends in Southeast Asia inferred from lake sediment records.

Science.gov (United States)

Engels, S; Fong, L S R Z; Chen, Q; Leng, M J; McGowan, S; Idris, M; Rose, N L; Ruslan, M S; Taylor, D; Yang, H

2018-04-01

Fossil fuel combustion leads to increased levels of air pollution, which negatively affects human health as well as the environment. Documented data for Southeast Asia (SEA) show a strong increase in fossil fuel consumption since 1980, but information on coal and oil combustion before 1980 is not widely available. Spheroidal carbonaceous particles (SCPs) and heavy metals, such as mercury (Hg), are emitted as by-products of fossil fuel combustion and may accumulate in sediments following atmospheric fallout. Here we use sediment SCP and Hg records from several freshwater lentic ecosystems in SEA (Malaysia, Philippines, Singapore) to reconstruct long-term, region-wide variations in levels of these two key atmospheric pollution indicators. The age-depth models of Philippine sediment cores do not reach back far enough to date first SCP presence, but single SCP occurrences are first observed between 1925 and 1950 for a Malaysian site. Increasing SCP flux is observed at our sites from 1960 onward, although individual sites show minor differences in trends. SCP fluxes show a general decline after 2000 at each of our study sites. While the records show broadly similar temporal trends across SEA, absolute SCP fluxes differ between sites, with a record from Malaysia showing SCP fluxes that are two orders of magnitude lower than records from the Philippines. Similar trends in records from China and Japan represent the emergence of atmospheric pollution as a broadly-based inter-region environmental problem during the 20th century. Hg fluxes were relatively stable from the second half of the 20th century onward. As catchment soils are also contaminated with atmospheric Hg, future soil erosion can be expected to lead to enhanced Hg flux into surface waters. Copyright © 2018 Elsevier Ltd. All rights reserved.

Analysis of radiation level on dinosaur fossil in Zigong

International Nuclear Information System (INIS)

Yang Changshu; Liang Shuzhi; Fan Zhengnian.

1995-01-01

Study on radiation level of dinosaur fossil and environment in conservation zone in Zigong, Sichuan has been done. The results showed that the γ radiation dose and radioactivity strength of 232 Th and 40 K in dinosaur fossil, soil and rock in the conservation zone were within the limits of radioactive background value in Zigong. Radioactivity strength of 238 U, 226 Ra in dinosaur fossil were 26.6 and 29.2 times higher than the rock of same layer respectively

THE GB/3D Fossil Types Online Database

Science.gov (United States)

Howe, M. P.; McCormick, T.

2012-12-01

The ICZN and the International Code of Nomenclature for algae, fungi and plants require that every species or subspecies of organism (living & fossil), should have a type or reference specimen to define its characteristic features. These specimens are held in collections around the world and must be available for study. Over time, type specimens can deteriorate or become lost. The British Geological Survey, the National Museum of Wales, the Sedgwick Museum Cambridge and the Oxford Museum of Natural History are working together to create an online database of the type fossils they hold. The web portal provides data about each specimen, searchable on taxonomic, stratigraphic and spatial criteria. For each specimen it is possible to view and download high resolution photographs, and for many of them, 'anaglyph' stereo pairs and 3D scans are available. The portal also provides educational resources (OERs). The rise to prominence of the Web has transformed expectations in accessing information and the Web is now usually the first port of call. However, while many geological museums are providing web-searchable text catalogues, few have undertaken a large-scale program of providing images and 3D models. This project has tackled the issues of merging four distinct data holdings, and setting up workflows to image and scan large numbers of disparate fossils, ranging from small invertebrate macrofossils to large vertebrate skeletal elements. There are three advantages in providing such resources: (1) All users can exploit the collections more efficiently. End-users can view specimens remotely and assess their nature, preservation quality and completeness - in some cases this may be sufficient. It will reduce the need for institutions to send specimens (which are often fragile and always irreplaceable) to researchers by post, or for researchers to make possibly long, expensive and environmentally damaging journeys. (2) A public outreach and education dividend - the ability to

Surface Model and Tomographic Archive of Fossil Primate and Other Mammal Holotype and Paratype Specimens of the Ditsong National Museum of Natural History, Pretoria, South Africa.

Directory of Open Access Journals (Sweden)

Justin W Adams

Full Text Available Nearly a century of paleontological excavation and analysis from the cave deposits of the Cradle of Humankind UNESCO World Heritage Site in northeastern South Africa underlies much of our understanding of the evolutionary history of hominins, other primates and other mammal lineages in the late Pliocene and early Pleistocene of Africa. As one of few designated fossil repositories, the Plio-Pleistocene Palaeontology Section of the Ditsong National Museum of Natural History (DNMNH; the former Transvaal Museum curates much of the mammalian faunas recovered from the fossil-rich deposits of major South African hominin-bearing localities, including the holotype and paratype specimens of many primate, carnivore, and other mammal species (Orders Primates, Carnivora, Artiodactyla, Eulipotyphla, Hyracoidea, Lagomorpha, Perissodactyla, and Proboscidea. Here we describe an open-access digital archive of high-resolution, full-color three-dimensional (3D surface meshes of all 89 non-hominin holotype, paratype and significant mammalian specimens curated in the Plio-Pleistocene Section vault. Surface meshes were generated using a commercial surface scanner (Artec Spider, Artec Group, Luxembourg, are provided in formats that can be opened in both open-source and commercial software, and can be readily downloaded either via an online data repository (MorphoSource or via direct request from the DNMNH. In addition to providing surface meshes for each specimen, we also provide tomographic data (both computerized tomography [CT] and microfocus [microCT] for a subset of these fossil specimens. This archive of the DNMNH Plio-Pleistocene collections represents the first research-quality 3D datasets of African mammal fossils to be made openly available. This simultaneously provides the paleontological community with essential baseline information (e.g., updated listing and 3D record of specimens in their current state of preservation and serves as a single resource of

Surface Model and Tomographic Archive of Fossil Primate and Other Mammal Holotype and Paratype Specimens of the Ditsong National Museum of Natural History, Pretoria, South Africa.

Science.gov (United States)

Adams, Justin W; Olah, Angela; McCurry, Matthew R; Potze, Stephany

2015-01-01

Nearly a century of paleontological excavation and analysis from the cave deposits of the Cradle of Humankind UNESCO World Heritage Site in northeastern South Africa underlies much of our understanding of the evolutionary history of hominins, other primates and other mammal lineages in the late Pliocene and early Pleistocene of Africa. As one of few designated fossil repositories, the Plio-Pleistocene Palaeontology Section of the Ditsong National Museum of Natural History (DNMNH; the former Transvaal Museum) curates much of the mammalian faunas recovered from the fossil-rich deposits of major South African hominin-bearing localities, including the holotype and paratype specimens of many primate, carnivore, and other mammal species (Orders Primates, Carnivora, Artiodactyla, Eulipotyphla, Hyracoidea, Lagomorpha, Perissodactyla, and Proboscidea). Here we describe an open-access digital archive of high-resolution, full-color three-dimensional (3D) surface meshes of all 89 non-hominin holotype, paratype and significant mammalian specimens curated in the Plio-Pleistocene Section vault. Surface meshes were generated using a commercial surface scanner (Artec Spider, Artec Group, Luxembourg), are provided in formats that can be opened in both open-source and commercial software, and can be readily downloaded either via an online data repository (MorphoSource) or via direct request from the DNMNH. In addition to providing surface meshes for each specimen, we also provide tomographic data (both computerized tomography [CT] and microfocus [microCT]) for a subset of these fossil specimens. This archive of the DNMNH Plio-Pleistocene collections represents the first research-quality 3D datasets of African mammal fossils to be made openly available. This simultaneously provides the paleontological community with essential baseline information (e.g., updated listing and 3D record of specimens in their current state of preservation) and serves as a single resource of high

Reforming fossil fuel prices in India: Dilemma of a developing economy

International Nuclear Information System (INIS)

Anand, Mukesh Kumar

2016-01-01

Over the period between 1990–1 and 2012–3, fossil fuel use on farms has risen and its indirect use in farming, particularly for non-energy purposes, is also growing. Consequently, both energy intensity and fossil fuel intensity are rising for Indian agriculture. But, these are declining for the aggregate Indian economy. Thus, revision of fossil fuel prices acquires greater significance for Indian agriculture than for rest of the economy. There are significant differences across crops. The crop-level analysis is supplemented by an alternative approach that utilizes a three-sector input–output (I–O) model for the Indian economy representing farming, fossil fuels, and rest of economy. Fossil fuels sector is assessed to portray, in general, strong forward linkages. The increase in total cost of farming, for a given change in fossil fuel prices, is estimated as a multiple of increase in direct input cost of fossil fuels in farming. From the three-sector aggregated economy this multiple was estimated at 3.99 for 1998–9. But it grew to 6.7 in 2007–8. The findings have stronger ramifications than commonly recognized, for inflation and cost of implementing the policy on food security. - Highlights: •Fossil fuels’ contribution in primary energy supply has risen from 55 to 75 per cent. •Energy intensity halved for aggregate GDP, but doubled for agricultural GDP. •Impact of fossil fuel price increase on farming costs mimics a widening spiral. •Total cost of farming may increase 6.7 times the increase in direct fuel input cost.

OH 83: A new early modern human fossil cranium from the Ndutu beds of Olduvai Gorge, Tanzania.

Science.gov (United States)

Reiner, Whitney B; Masao, Fidelis; Sholts, Sabrina B; Songita, Agustino Venance; Stanistreet, Ian; Stollhofen, Harald; Taylor, R E; Hlusko, Leslea J

2017-11-01

Herein we introduce a newly recovered partial calvaria, OH 83, from the upper Ndutu Beds of Olduvai Gorge, Tanzania. We present the geological context of its discovery and a comparative analysis of its morphology, placing OH 83 within the context of our current understanding of the origins and evolution of Homo sapiens. We comparatively assessed the morphology of OH 83 using quantitative and qualitative data from penecontemporaneous fossils and the W.W. Howells modern human craniometric dataset. OH 83 is geologically dated to ca. 60-32 ka. Its morphology is indicative of an early modern human, falling at the low end of the range of variation for post-orbital cranial breadth, the high end of the range for bifrontal breadth, and near average in frontal length. There have been numerous attempts to use cranial anatomy to define the species Homo sapiens and identify it in the fossil record. These efforts have not met wide agreement by the scientific community due, in part, to the mosaic patterns of cranial variation represented by the fossils. The variable, mosaic pattern of trait expression in the crania of Middle and Late Pleistocene fossils implies that morphological modernity did not occur at once. However, OH 83 demonstrates that by ca. 60-32 ka modern humans in Africa included individuals that are at the fairly small and gracile range of modern human cranial variation. © 2017 Wiley Periodicals, Inc.

Fossil plants from Romanian deposits of Bacles, Dolj District, Romania

Directory of Open Access Journals (Sweden)

Nicolae T̡icleanu

2001-09-01

Full Text Available From the Middle Romanian lacustrine deposits of the Oltenia province, the authors describe the youngest fossil flora known until now in Oltenia. The inventory of the fossil flora includes the following taxa: Taxodium dubium, ?Platanus platanifolia, Ulmus laevis, Quercus roburoides, Q. cf. muehlenbergii, Carya serraefolia, Acer cf. tricuspidatum and Salix sp. In the Bâcleş fossil flora, Glyptostrobus europaeus, which is a thermophilous and shows a high frequency in all Oltenia area till the XV-th coal seam, is absent. Consequently, having in view the high frequency of Taxodium dubium, which indicate temperate climate conditions, the other consider that the fossil flora from Bâcleş is much more younger and marks an important cooling. From palaeofloristic point of view, the study of Bâcleş fossil flora is indicative for river meadow forest and, probably, flat plain forest environments.

THE XMM CLUSTER SURVEY: THE STELLAR MASS ASSEMBLY OF FOSSIL GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Harrison, Craig D.; Miller, Christopher J. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Richards, Joseph W.; Deadman, Paul-James [Center for Time Domain Informatics, University of California, Berkeley, CA 94720 (United States); Lloyd-Davies, E. J.; Kathy Romer, A.; Mehrtens, Nicola; Liddle, Andrew R. [Astronomy Centre, University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom); Hoyle, Ben [Institute of Sciences of the Cosmos (ICCUB) and IEEC, Physics Department, University of Barcelona, Barcelona 08024 (Spain); Hilton, Matt [Astrophysics and Cosmology Research Unit, School of Mathematical Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban 4000 (South Africa); Stott, John P.; Capozzi, Diego; Collins, Chris A. [Astrophysics Research Institute, Liverpool John Moores University, Twelve Quays House, Egerton Wharf, Birkenhead CH41 1LD (United Kingdom); Sahlen, Martin [Oskar Klein Centre for Cosmoparticle Physics, Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Stanford, S. Adam [Physics Department, University of California, Davis, CA 95616 (United States); Viana, Pedro T. P., E-mail: craigha@umich.edu [Centro de Astrofisica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal)

2012-06-10

This paper presents both the result of a search for fossil systems (FSs) within the XMM Cluster Survey and the Sloan Digital Sky Survey and the results of a study of the stellar mass assembly and stellar populations of their fossil galaxies. In total, 17 groups and clusters are identified at z < 0.25 with large magnitude gaps between the first and fourth brightest galaxies. All the information necessary to classify these systems as fossils is provided. For both groups and clusters, the total and fractional luminosity of the brightest galaxy is positively correlated with the magnitude gap. The brightest galaxies in FSs (called fossil galaxies) have stellar populations and star formation histories which are similar to normal brightest cluster galaxies (BCGs). However, at fixed group/cluster mass, the stellar masses of the fossil galaxies are larger compared to normal BCGs, a fact that holds true over a wide range of group/cluster masses. Moreover, the fossil galaxies are found to contain a significant fraction of the total optical luminosity of the group/cluster within 0.5 R{sub 200}, as much as 85%, compared to the non-fossils, which can have as little as 10%. Our results suggest that FSs formed early and in the highest density regions of the universe and that fossil galaxies represent the end products of galaxy mergers in groups and clusters.

100 years of discovery of the Burgess Shale 1909-2009 : a celebration of the discovery of the world's most important fossils

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

The centennial celebration of the discovery of the Burgess Shale consisted of informative science presentations to the general public. Scientific presenters also participated in guided hikes in Yoho National Park within the Canadian Rockies where the Burgess Shale can be found. The first Burgess Shale fossils were discovered in 1909 by Charles D. Walcott. Thousands of specimens have since been collected from the quarry named after him. The informative science presentations described the burst of biodiversity of marine plants and marine invertebrate animals that lived in a shallow sea in the vicinity of a massive carbonate reef during the Cambrian Period. They described the unusual conditions that allowed for the very rare preservation of the animals in the Burgess Shale. The Burgess Shale fossils merit special interest because they reveal how animal life appeared on Earth better than any other fossil record. In addition to the geological history of the Burgess Shale area, the centennial lectures also addressed topics such as climate and the geological record of climate change; the influence of continental drift on evolution; and fluid geochemistry in the Western Canada Foreland Basin and paleoclimate influence. The Burgess Shale was designated a UNESCO World Heritage Site in 1981 as it provides key information about evolution of life on Earth. refs. figs.

Instrumentation and control for fossil-energy processes

Energy Technology Data Exchange (ETDEWEB)

1982-09-01

The 1982 symposium on instrumentation and control for fossil energy processes was held June 7 through 9, 1982, at Adam's Mark Hotel, Houston, Texas. It was sponsored by the US Department of Energy, Office of Fossil Energy; Argonne National Laboratory; and the Society for Control and Instrumentation of Energy Processes. Fifty-two papers have been entered individually into EDB and ERA; eleven papers had been entered previously from other sources. (LTN)

NOTES ON FOSSIL CHITONS. 5. POLYPLACOPHORA FROM THE PLIOCENE OF WESTERN LIGURIA, NORTHWEST ITALY

Directory of Open Access Journals (Sweden)

BRUNO DELL'ANGELO

2013-03-01

Full Text Available This study describes the chiton fauna (Mollusca, Polyplacophora from deposits of the Pliocene marine sequence of Western Liguria in northwestern Italy between Genova (Genoa and Ventimiglia. The studied fossils consist of 9,657 valves from nine sites (Bussana, Rio Sant'Antonino, Garlenda, Salea, Caranchi, Rio Torsero, Zinola, Sestri Ponente, and Borzoli; see Fig. 1 taken from the lower clayey formation named Argille di Ortovero (Ortovero Clay. From these we identified 31 species, 22 of which were already known, 5 are identified only at generic level, and four are described as new: Leptochiton josei sp. n., Ischnochiton ligusticus sp. n., Connexochiton roccai sp. n., and Lepidochitona pliocinerea sp. n. Only three species (Lepidopleurus cajetanus, Chiton corallinus and Acanthochitona fascicularis occur in all the studied sites but, even so, it is difficult to evaluate their relative prevalence. Ch. corallinus and Lepidop. cajetanus are most common, representing 46%  and 31% respectively of the total valves found. Some species found are particularly noteworthy; Lept. alveolus previously not known as a fossil, except a dubiously identified record from the Eocene/Oligocene of Washington; Lept. bedullii and I. martinelli are known only from few Pliocene localities. Four species are described as new, and this increases the number of Mediterranean Pliocene determined species known to 37. Connexochiton roccai sp. n. represent the first report of Connexochiton as a fossil. Seventeen (55% of the species found are still living in the Mediterranean Sea and 13 of these also occur in the eastern Atlantic. Only one species, Lept. alveolus, occurs as a living species in the Atlantic but is absent from the Mediterranean Sea. Five determined species are known only from Mediterranean Pliocene, and 12 are recorded for the first time from the Ligurian Pliocene. The analysis of the Ligurian samples suggests a shallow water depositional environment, possibly from

Sanitary effects of fossil fuels; Effets sanitaires des combustibles fossiles

Energy Technology Data Exchange (ETDEWEB)

Nifenecker, H. [Centre National de la Recherche Scientifique (IN2P3/CNRS), 38 - Grenoble (France)

2006-07-01

In this compilation are studied the sanitary effects of fossil fuels, behavioral and environmental sanitary risks. The risks in connection with the production, the transport and the distribution(casting) are also approached for the oil(petroleum), the gas and the coal. Accidents in the home are evoked. The risks due to the atmospheric pollution are seen through the components of the atmospheric pollution as well as the sanitary effects of this pollution. (N.C.)

Fossil human remains from Bolomor Cave (Valencia, Spain).

Science.gov (United States)

Arsuaga, Juan Luis; Fernández Peris, Josep; Gracia-Téllez, Ana; Quam, Rolf; Carretero, José Miguel; Barciela González, Virginia; Blasco, Ruth; Cuartero, Felipe; Sañudo, Pablo

2012-05-01

Systematic excavations carried out since 1989 at Bolomor Cave have led to the recovery of four Pleistocene human fossil remains, consisting of a fibular fragment, two isolated teeth, and a nearly complete adult parietal bone. All of these specimens date to the late Middle and early Late Pleistocene (MIS 7-5e). The fibular fragment shows thick cortical bone, an archaic feature found in non-modern (i.e. non-Homo sapiens) members of the genus Homo. Among the dental remains, the lack of a midtrigonid crest in the M(1) represents a departure from the morphology reported for the majority of Neandertal specimens, while the large dimensions and pronounced shoveling of the marginal ridges in the C(1) are similar to other European Middle and late Pleistocene fossils. The parietal bone is very thick, with dimensions that generally fall above Neandertal fossils and resemble more closely the Middle Pleistocene Atapuerca (SH) adult specimens. Based on the presence of archaic features, all the fossils from Bolomor are attributed to the Neandertal evolutionary lineage. Copyright © 2012 Elsevier Ltd. All rights reserved.

The fossil record of South American short-faced bears (Ursidae, Tremarctinae)

OpenAIRE

Bond, Mariano; Tonni, Eduardo Pedro; Soibelzon, Leopoldo Héctor

2005-01-01

The present study includes a review of the geographic and stratigraphic distribution of short-faced bears (Ursidae, Tremarctinae) in South America. In addition, the authors discuss biogeographic hypotheses regarding the origin of South American tremarctines. The Tremarctinae subfamily is distributed exclusively in America, from Alaska to southern Patagonia. Its biochron comprises the temporal lapse between Late Miocene and recent times; the first record of Tremarctinae in North America corres...

NEW FOSSIL VERTEBRATE REMAINS FROM SAN GIOVANNI DI SINIS (LATE PLEISTOCENE, SARDINIA: THE LAST MAUREMYS (REPTILIA, TESTUDINES IN THE CENTRAL MEDITERRANEAN

Directory of Open Access Journals (Sweden)

FRANCESCO CHESI

2007-07-01

Full Text Available New fossil vertebrates from the most representative Upper Pleistocene section (Tyrrhenian, MIS 5e of the outcrop of San Giovanni di Sinis (Oristano, Sardinia are here reported and described. The fossils, although scarce and fragmentary, document the occurrence of a terrapin (Mauremys sp. and the endemic Sardinian deer (Praemegaceros cazioti. Significant is the occurrence of the terrapin because it is the youngest representative of the genus in the central Mediterranean area where it is extinct at present. The Late Pleistocene extinction of Mauremys in Italy follows the same pattern of other Mediterranean reptiles, in being in some cases delayed on the islands. A comparison of the modern range of Mauremys and that of the pond turtle, Emys, as well as of their past ranges as evidenced by the fossil record, might suggest that some sort of thermophily (at least during pre-hatching stages characterized the former taxon and is responsible for its past and present distribution. SHORT NOTE

Natural product terpenoids in Eocene and Miocene conifer fossils.

Science.gov (United States)

Otto, Angelika; White, James D; Simoneit, Bernd R T

2002-08-30

Numerous saturated and aromatic hydrocarbons, but not polar compounds, originating from plants and microorganisms (biomarkers) have been reported in sediments, coals, and petroleum. Here we describe natural product terpenoids found in two fossil conifers, Taxodium balticum (Eocene) and Glyptostrobus oregonensis (Miocene). A similar terpenoid pattern is also observed in extant Taxodium distichum. The preservation of characteristic terpenoids (unaltered natural products) in the fossil conifers supports their systematic assignment to the Cypress family (Cupressaceae sensu lato). The results also show that fossil conifers can contain polar terpenoids, which are valuable markers for (paleo)chemosystematics and phylogeny.

ESR dating studies on fossil of elaphurus davidianus horn

International Nuclear Information System (INIS)

Chen Shiming; Wang Hong; Tang Jingjuan; Yan Xiaomin; Guo Shiqing

1991-01-01

On the basis of studies on elephant tooth fossil, ESR dating of elaphurus davidianus horn fossil found in Anhui Province was reported. The sample examined by TEM electron spectrum is composed of hydroxyapatite. ESR experiments showed that the solid bone sample can be chosen as dating material. According to the contents of U, Th and K in the sample determined by ICP, the annual dose of radiation was calculated by using the linear uranium accumulation model and disequilibrium decay. The age of this fossil was determined to be 2.5 x 10 4 years

Modernist architecture in Barcelona reveals a new trace fossil from the Miocene of Montjuïc (NE Spain)

Energy Technology Data Exchange (ETDEWEB)

Belaústegui, Z.; Belaústegui, A.

2017-11-01

A new ichnotaxon, Lapillitubus montjuichensis n. i gen. n. isp., is described from the middle Miocene (Serravallian) of Montjuïc mountain (Barcelona, northeastern Spain). This ichnotaxon consists of a horizontal to vertical, cylindrical burrow with an agglutinated lining exclusively composed of lithoclasts. Lapillitubus montjuichensis is interpreted as the result of the burrowing activity of a deposit- or suspension-feeding annelid worm. This new ichnotaxon extends the record of the informal group known as clast-armored or agglutinated trace fossils. In addition, since part of its type material is located in the blocks that make up the façades of several modernist buildings in the city of Barcelona, this new ichnotaxon highlights the importance of fossils in urban settings for those cases in which natural outcrops are reduced, restricted or even missing.

Modernist architecture in Barcelona reveals a new trace fossil from the Miocene of Montjuïc (NE Spain)

International Nuclear Information System (INIS)

Belaústegui, Z.; Belaústegui, A.

2017-01-01

A new ichnotaxon, Lapillitubus montjuichensis n. i gen. n. isp., is described from the middle Miocene (Serravallian) of Montjuïc mountain (Barcelona, northeastern Spain). This ichnotaxon consists of a horizontal to vertical, cylindrical burrow with an agglutinated lining exclusively composed of lithoclasts. Lapillitubus montjuichensis is interpreted as the result of the burrowing activity of a deposit- or suspension-feeding annelid worm. This new ichnotaxon extends the record of the informal group known as clast-armored or agglutinated trace fossils. In addition, since part of its type material is located in the blocks that make up the façades of several modernist buildings in the city of Barcelona, this new ichnotaxon highlights the importance of fossils in urban settings for those cases in which natural outcrops are reduced, restricted or even missing.

Fossil Energy Program annual progress report for April 1994 through March 1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-06-01

This report covers progress made during the period April 1, 1994, through March 31, 1995, for research and development projects that contribute to the advancement of various fossil energy technologies. Projects on the Fossil Energy Program are supported by the DOE Office of Fossil Energy, and DOE Morgantown Energy Technology Center, the DOE Pittsburgh Energy Technology Center, the DOE Fossil Energy Clean Coal Technology Program, the DOE Bartlesville Project Office, and the DOE Fossil Energy Office of Strategic Petroleum Reserve. The following research areas are covered in this report: Materials research and development; Environmental analysis support; Bioprocessing research; Coal combustion research; and Fossil fuels supplies modeling and research. Selected papers have been processed separately for inclusion in the Energy Science an Technology database.

The Fossil Fuel Divestment Movement: An Ethical Dilemma for the Geosciences?

Science.gov (United States)

Greene, C. H.; Kammen, D. M.

2014-12-01

For over 200 years, fossil fuels have been the basis for an industrial revolution that has delivered a level of prosperity to modern society unimaginable during the previous 5000 years of human civilization. However, society's dependence on fossil fuels is coming to an end for two reasons. The first reason is because our fossil fuel reserves are running out, oil in this century, natural gas during the next century, and coal a few centuries later. The second reason is because fossil fuels are having a devastating impact on the habitability of our planet, disrupting our climate system and acidifying our oceans. So the question is not whether we will discontinue using fossil fuels, but rather whether we will stop using them before they do irreparable damage to the Earth's life-support systems. Within our geoscience community, climate scientists have determined that a majority of existing fossil fuel reserves must remain unburned if dangerous climate change and ocean acidification are to be avoided. In contrast, Exxon-Mobil, Shell, and other members of the fossil fuel industry are pursuing a business model that assumes all of their reserves will be burned and will not become stranded assets. Since the geosciences have had a long and mutually beneficial relationship with the fossil fuel industry, this inherent conflict between climate science and industrial interests presents an ethical dilemma for many geoscientists. This conflict is further heightened by the fossil fuel divestment movement, which is underway at over 400 college and university campuses around the world. This presentation will explore some of the ethical and financial issues being raised by the divestment movement from a geoscientist's perspective.

Fossils and palaeontological distributions of Macaranga and Mallotus (Euphorbiaceae)

NARCIS (Netherlands)

Nucete, M.; van Konijnenburg-van Cittert, J.H.A.; van Welzen, P.C.

2012-01-01

The correct identification of described plant fossils from the sister genera Macaranga and Mallotus (Euphorbiaceae) needs to be confirmed in order to correctly date their phylogeny and map their palaeontological distributions. Previous identifications of fossil specimens often appear to be

Proceedings of the fourth annual conference on fossil energy materials

Energy Technology Data Exchange (ETDEWEB)

Judkins, R.R.; Braski, D.N. (comps.)

1990-08-01

The Fourth Annual Conference on Fossil Energy Materials was held in Oak Ridge, Tennessee, on may 15--17, 1990. The meeting was sponsored by the US Department of Energy's Office of Fossil Energy through the Advanced Research and Technology Development (AR TD) Materials Program, and ASM International. The objective of the AR TD Materials Program is to conduct research and development on materials for longer-term fossil energy applications as well as for generic needs of various fossil fuel technologies. The work is divided into the following categories: (1) Ceramics, (2) New Alloys, (3) Corrosion and Erosion, and (4) Technology Assessment and Technology Transfer. Individual projects are processed separately for the data bases.

Brief communication: Paleobiological inferences on the locomotor repertoire of extinct hominoids based on femoral neck cortical thickness: The fossil great ape hispanopithecus laietanus as a test-case study.

Science.gov (United States)

Pina, Marta; Alba, David M; Almécija, Sergio; Fortuny, Josep; Moyà-Solà, Salvador

2012-09-01

The relationship between femoral neck superior and inferior cortical thickness in primates is related to locomotor behavior. This relationship has been employed to infer bipedalism in fossil hominins, although bipeds share the same pattern of generalized quadrupeds, where the superior cortex is thinner than the inferior one. In contrast, knuckle-walkers and specialized suspensory taxa display a more homogeneous distribution of cortical bone. These different patterns, probably related to the range of movement at the hip joint and concomitant differences in the load stresses at the femoral neck, are very promising for making locomotor inferences in extinct primates. To evaluate the utility of this feature in the fossil record, we relied on computed tomography applied to the femur of the Late Miocene hominoid Hispanopithecus laietanus as a test-case study. Both an orthograde body plan and orang-like suspensory adaptations had been previously documented for this taxon on different anatomical grounds, leading to the hypothesis that this fossil ape should display a modern ape-like distribution of femoral neck cortical thickness. This is confirmed by the results of this study, leading to the conclusion that Hispanopithecus represents the oldest evidence of a homogeneous cortical bone distribution in the hominoid fossil record. Our results therefore strengthen the utility of femoral neck cortical thickness for making paleobiological inferences on the locomotor repertoire of fossil primates. This feature would be particularly useful for assessing the degree of orthograde arboreal locomotor behaviors vs. terrestrial bipedalism in putative early hominins. Copyright © 2012 Wiley Periodicals, Inc.

Global history of the ancient monocot family Araceae inferred with models accounting for past continental positions and previous ranges based on fossils.

Science.gov (United States)

Nauheimer, Lars; Metzler, Dirk; Renner, Susanne S

2012-09-01

The family Araceae (3790 species, 117 genera) has one of the oldest fossil records among angiosperms. Ecologically, members of this family range from free-floating aquatics (Pistia and Lemna) to tropical epiphytes. Here, we infer some of the macroevolutionary processes that have led to the worldwide range of this family and test how the inclusion of fossil (formerly occupied) geographical ranges affects biogeographical reconstructions. Using a complete genus-level phylogeny from plastid sequences and outgroups representing the 13 other Alismatales families, we estimate divergence times by applying different clock models and reconstruct range shifts under different models of past continental connectivity, with or without the incorporation of fossil locations. Araceae began to diversify in the Early Cretaceous (when the breakup of Pangea was in its final stages), and all eight subfamilies existed before the K/T boundary. Early lineages persist in Laurasia, with several relatively recent entries into Africa, South America, South-East Asia and Australia. Water-associated habitats appear to be ancestral in the family, and DNA substitution rates are especially high in free-floating Araceae. Past distributions inferred when fossils are included differ in nontrivial ways from those without fossils. Our complete genus-level time-scale for the Araceae may prove to be useful for ecological and physiological studies. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

Clustering fossils in solid inflation

Energy Technology Data Exchange (ETDEWEB)

Akhshik, Mohammad, E-mail: m.akhshik@ipm.ir [Department of Physics, Sharif University of Technology, Tehran (Iran, Islamic Republic of)

2015-05-01

In solid inflation the single field non-Gaussianity consistency condition is violated. As a result, the long tenor perturbation induces observable clustering fossils in the form of quadrupole anisotropy in large scale structure power spectrum. In this work we revisit the bispectrum analysis for the scalar-scalar-scalar and tensor-scalar-scalar bispectrum for the general parameter space of solid. We consider the parameter space of the model in which the level of non-Gaussianity generated is consistent with the Planck constraints. Specializing to this allowed range of model parameter we calculate the quadrupole anisotropy induced from the long tensor perturbations on the power spectrum of the scalar perturbations. We argue that the imprints of clustering fossil from primordial gravitational waves on large scale structures can be detected from the future galaxy surveys.

A Late Jurassic fossil assemblage in Gondwana: Biostratigraphy and correlations of the Tacuarembó Formation, Parana Basin, Uruguay

Science.gov (United States)

Perea, Daniel; Soto, Matías; Veroslavsky, Gerardo; Martínez, Sergio; Ubilla, Martín

2009-08-01

The Tacuarembó Formation has yielded a fossil assemblage that includes the best known body fossils, consisting of isolated scales, teeth, spines, and molds of bones, recovered from thin and patchy bonebeds, from the Botucatu Desert, Parana Basin, South America. The remains are preserved in the sandstones widespread around the city of Tacuarembó. We propose a new formalized nomenclature for the Tacuarembó Formation, naming its "Lower" and "Upper" members as the Batoví (new name) and Rivera (new rank) members, respectively. An assemblage zone is defined for the Batoví Member (fluviolacustrine and aeolian deposits). In this unit, the freshwater hybodontid shark Priohybodusarambourgi D'Erasmo is well represented. This species was previously recorded in Late Jurassic-Early Cretaceous units of the Sahara and the southern Arabian Peninsula. Globally considered, the fossil assemblage of this member ( P. arambourgi, dipnoan fishes, Ceratosaurus-like theropods, and conchostracans) is indicative of a Kimmeridgian-Tithonian age, which in combination with the stratigraphic relationships of the Tacuarembó Formation with the overlying basalts of the Arapey Formation (132 My average absolute age) implies that the latter was deposited during the Kimmeridgian-Hauterivian interval.

Melanins in Fossil Animals: Is It Possible to Infer Life History Traits from the Coloration of Extinct Species?

Science.gov (United States)

Negro, Juan J; Finlayson, Clive; Galván, Ismael

2018-01-23

Paleo-colour scientists have recently made the transition from describing melanin-based colouration in fossil specimens to inferring life-history traits of the species involved. Two such cases correspond to counter-shaded dinosaurs: dark-coloured due to melanins dorsally, and light-coloured ventrally. We believe that colour reconstruction of fossils based on the shape of preserved microstructures-the majority of paleo-colour studies involve melanin granules-is not without risks. In addition, animals with contrasting dorso-ventral colouration may be under different selection pressures beyond the need for camouflage, including, for instance, visual communication or ultraviolet (UV) protection. Melanin production is costly, and animals may invest less in areas of the integument where pigments are less needed. In addition, melanocytes exposed to UV radiation produce more melanin than unexposed melanocytes. Pigment economization may thus explain the colour pattern of some counter-shaded animals, including extinct species. Even in well-studied extant species, their diversity of hues and patterns is far from being understood; inferring colours and their functions in species only known from one or few specimens from the fossil record should be exerted with special prudence.

Melanins in Fossil Animals: Is It Possible to Infer Life History Traits from the Coloration of Extinct Species?

Science.gov (United States)

Negro, Juan J.; Finlayson, Clive; Galván, Ismael

2018-01-01

Paleo-colour scientists have recently made the transition from describing melanin-based colouration in fossil specimens to inferring life-history traits of the species involved. Two such cases correspond to counter-shaded dinosaurs: dark-coloured due to melanins dorsally, and light-coloured ventrally. We believe that colour reconstruction of fossils based on the shape of preserved microstructures—the majority of paleo-colour studies involve melanin granules—is not without risks. In addition, animals with contrasting dorso-ventral colouration may be under different selection pressures beyond the need for camouflage, including, for instance, visual communication or ultraviolet (UV) protection. Melanin production is costly, and animals may invest less in areas of the integument where pigments are less needed. In addition, melanocytes exposed to UV radiation produce more melanin than unexposed melanocytes. Pigment economization may thus explain the colour pattern of some counter-shaded animals, including extinct species. Even in well-studied extant species, their diversity of hues and patterns is far from being understood; inferring colours and their functions in species only known from one or few specimens from the fossil record should be exerted with special prudence. PMID:29360744

Melanins in Fossil Animals: Is It Possible to Infer Life History Traits from the Coloration of Extinct Species?

Directory of Open Access Journals (Sweden)

Juan J. Negro

2018-01-01

Full Text Available Paleo-colour scientists have recently made the transition from describing melanin-based colouration in fossil specimens to inferring life-history traits of the species involved. Two such cases correspond to counter-shaded dinosaurs: dark-coloured due to melanins dorsally, and light-coloured ventrally. We believe that colour reconstruction of fossils based on the shape of preserved microstructures—the majority of paleo-colour studies involve melanin granules—is not without risks. In addition, animals with contrasting dorso-ventral colouration may be under different selection pressures beyond the need for camouflage, including, for instance, visual communication or ultraviolet (UV protection. Melanin production is costly, and animals may invest less in areas of the integument where pigments are less needed. In addition, melanocytes exposed to UV radiation produce more melanin than unexposed melanocytes. Pigment economization may thus explain the colour pattern of some counter-shaded animals, including extinct species. Even in well-studied extant species, their diversity of hues and patterns is far from being understood; inferring colours and their functions in species only known from one or few specimens from the fossil record should be exerted with special prudence.

Emissions Scenarios and Fossil-fuel Peaking

Science.gov (United States)

Brecha, R.

2008-12-01

Intergovernmental Panel on Climate Change (IPCC) emissions scenarios are based on detailed energy system models in which demographics, technology and economics are used to generate projections of future world energy consumption, and therefore, of greenhouse gas emissions. Built into the assumptions for these scenarios are estimates for ultimately recoverable resources of various fossil fuels. There is a growing chorus of critics who believe that the true extent of recoverable fossil resources is much smaller than the amounts taken as a baseline for the IPCC scenarios. In a climate optimist camp are those who contend that "peak oil" will lead to a switch to renewable energy sources, while others point out that high prices for oil caused by supply limitations could very well lead to a transition to liquid fuels that actually increase total carbon emissions. We examine a third scenario in which high energy prices, which are correlated with increasing infrastructure, exploration and development costs, conspire to limit the potential for making a switch to coal or natural gas for liquid fuels. In addition, the same increasing costs limit the potential for expansion of tar sand and shale oil recovery. In our qualitative model of the energy system, backed by data from short- and medium-term trends, we have a useful way to gain a sense of potential carbon emission bounds. A bound for 21st century emissions is investigated based on two assumptions: first, that extractable fossil-fuel resources follow the trends assumed by "peak oil" adherents, and second, that little is done in the way of climate mitigation policies. If resources, and perhaps more importantly, extraction rates, of fossil fuels are limited compared to assumptions in the emissions scenarios, a situation can arise in which emissions are supply-driven. However, we show that even in this "peak fossil-fuel" limit, carbon emissions are high enough to surpass 550 ppm or 2°C climate protection guardrails. Some

Fossil fuels in the 21st century.

Science.gov (United States)

Lincoln, Stephen F

2005-12-01

An overview of the importance of fossil fuels in supplying the energy requirements of the 21st century, their future supply, and the impact of their use on global climate is presented. Current and potential alternative energy sources are considered. It is concluded that even with substantial increases in energy derived from other sources, fossil fuels will remain a major energy source for much of the 21st century and the sequestration of CO2 will be an increasingly important requirement.

Development of concepts for a zero-fossil-energy greenhouse

NARCIS (Netherlands)

Ooster, A. van 't; Henten, E.J. van; Janssen, E.G.O.N.; Bot, G.P.A.; Dekker, E.

2008-01-01

Dutch government and greenhouse horticultural practice aim for strongly reduced fossil energy use and of environmental loads in 2010 and energy neutral greenhouses in 2020. This research aims to design a greenhouse concept with minimal use of fossil energy and independent of nearby greenhouses. The

Age and stratigraphic context of Pliopithecus and associated fauna from Miocene sedimentary strata at Damiao, Inner Mongolia, China

NARCIS (Netherlands)

Kaakinen, Anu; Abdul Aziz, Hayfaa; Passey, Benjamin H.; Zhang, Zhaoqun; Liu, Liping; Salminen, Johanna; Wang, Lihua; Krijgsman, Wout; Fortelius, Mikael

2015-01-01

Since the discovery of mammalian fossils in Central Inner Mongolia in the beginning of the 20th century, this area has produced a rich and diverse record of Miocene faunas. Nevertheless, the stratigraphy has remained poorly constrained owing to scattered faunal horizons and lack of continuous

Material flow analysis of fossil fuels in China during 2000-2010.

Science.gov (United States)

Wang, Sheng; Dai, Jing; Su, Meirong

2012-01-01

Since the relationship between the supply and demand of fossil fuels is on edge in the long run, the contradiction between the economic growth and limited resources will hinder the sustainable development of the Chinese society. This paper aims to analyze the input of fossil fuels in China during 2000-2010 via the material flow analysis (MFA) that takes hidden flows into account. With coal, oil, and natural gas quantified by MFA, three indexes, consumption and supply ratio (C/S ratio), resource consumption intensity (RCI), and fossil fuels productivity (FFP), are proposed to reflect the interactions between population, GDP, and fossil fuels. The results indicated that in the past 11 years, China's requirement for fossil fuels has been increasing continuously because of the growing mine productivity in domestic areas, which also leads to a single energy consumption structure as well as excessive dependence on the domestic exploitation. It is advisable to control the fossil fuels consumption by energy recycling and new energy facilities' popularization in order to lead a sustainable access to nonrenewable resources and decrease the soaring carbon emissions.

Fossil fuel power generation within the European Research Area

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-12-10

The report is the first in a series of three produced by the PowerClean Thematic Network that looks at and defines future requirements for research and development of fossil fuel power generation in the European Union. It makes the case for fossil fuel R & D with emphasis on the need for clean coal technologies (to increased efficiency and other CO{sub 2} capture and storage) For satisfying future energy demands of the enlarged European Union between now and 2030. The report concludes that affirmative R, D and D action is needed to support the EU power industry, working together on a Europe-wide basis, to establish the use of coal and other fossil fuels in near-zero emissions power plant. The role model would be the European Research Area, as in the Sixth Framework Programme (FP6), but with a more comprehensive range of technical objectives recognising the importance of fossil fuels. Section headings are: introduction; current energy use; future needs and requirements; the future for clean fossil fuel energy in Europe; comparison with approaches adopted elsewhere (USA Vision 21 and FutureGen programmes, Japan); and responsibilities for EU coal R, D & D. 14 refs., 9 figs., 4 tabs.

An econometrics view of worldwide fossil fuel consumption and the role of US

International Nuclear Information System (INIS)

Shafiee, Shahriar; Topal, Erkan

2008-01-01

Crude oil, coal and gas, known as fossil fuels, play a crucial role in the global economy. This paper proposes new econometrics modelling to demonstrate the trend of fossil fuels consumption. The main variables affecting consumption trends are: world reserves, the price of fossil fuels, US production and US net imports. All variables have been analysed individually for more than half a century. The research found that while the consumption of fossil fuels worldwide has increased trends in the US production and net imports have been dependent on the type of fossil fuels. Most of the US coal and gas production has been for domestic use, which is why it does not have a strong influence on worldwide fossil fuel prices. Moreover, the reserves of fossil fuels have not shown any diminution during the last couple of decades and predictions that they were about to run out are not substantiated. The nominal and real price of fossil fuels was found to change depending on the type. Finally, estimates of three econometric models for the consumption of fossil fuels from 1949 to 2006 are presented which identify the effects of significant variables

Partially incorrect fossil data augment analyses of discrete trait evolution in living species.

Science.gov (United States)

Puttick, Mark N

2016-08-01

Ancestral state reconstruction of discrete character traits is often vital when attempting to understand the origins and homology of traits in living species. The addition of fossils has been shown to alter our understanding of trait evolution in extant taxa, but researchers may avoid using fossils alongside extant species if only few are known, or if the designation of the trait of interest is uncertain. Here, I investigate the impacts of fossils and incorrectly coded fossils in the ancestral state reconstruction of discrete morphological characters under a likelihood model. Under simulated phylogenies and data, likelihood-based models are generally accurate when estimating ancestral node values. Analyses with combined fossil and extant data always outperform analyses with extant species alone, even when around one quarter of the fossil information is incorrect. These results are especially pronounced when model assumptions are violated, such as when there is a trend away from the root value. Fossil data are of particular importance when attempting to estimate the root node character state. Attempts should be made to include fossils in analysis of discrete traits under likelihood, even if there is uncertainty in the fossil trait data. © 2016 The Authors.

Mineralogy of Non-Silicified Fossil Wood

Directory of Open Access Journals (Sweden)

George E. Mustoe

2018-03-01

Full Text Available The best-known and most-studied petrified wood specimens are those that are mineralized with polymorphs of silica: opal-A, opal-C, chalcedony, and quartz. Less familiar are fossil woods preserved with non-silica minerals. This report reviews discoveries of woods mineralized with calcium carbonate, calcium phosphate, various iron and copper minerals, manganese oxide, fluorite, barite, natrolite, and smectite clay. Regardless of composition, the processes of mineralization involve the same factors: availability of dissolved elements, pH, Eh, and burial temperature. Permeability of the wood and anatomical features also plays important roles in determining mineralization. When precipitation occurs in several episodes, fossil wood may have complex mineralogy.

Education Program on Fossil Resources Including Coal

Science.gov (United States)

Usami, Masahiro

Fossil fuels including coal play a key role as crucial energies in contributing to economic development in Asia. On the other hand, its limited quantity and the environmental problems causing from its usage have become a serious global issue and a countermeasure to solve such problems is very much demanded. Along with the pursuit of sustainable development, environmentally-friendly use of highly efficient fossil resources should be therefore, accompanied. Kyushu-university‧s sophisticated research through long years of accumulated experience on the fossil resources and environmental sectors together with the advanced large-scale commercial and empirical equipments will enable us to foster cooperative research and provide internship program for the future researchers. Then, this program is executed as a consignment business from the Ministry of Economy, Trade and Industry from 2007 fiscal year to 2009 fiscal year. The lecture that uses the textbooks developed by this program is scheduled to be started a course in fiscal year 2010.

Early to Middle Jurassic palaeoenvironmental changes: High resolution δ13C and δ18O records from the UK

DEFF Research Database (Denmark)

Korte, Christoph; Hesselbo, Stephen; Ullmann, Clemens Vinzenz

Low-Mg-calcite fossils, such as bivalves, belemnites and brachiopods, and bulk rocks have been extensively utilized to reconstruct past seawater chemistry and paleoenviron¬mental changes. Recent work on major bioevents demonstrated that particularly higher resolution stable isotope records...... are necessary to reveal short-term paleoenviron¬mental fluctuations and, in addition, to discover its causes. Here we present a new high resolution carbon and oxygen isotope dataset generated from low-Mg-calcite fossils, fossil wood and bulk rocks collected from Early to Middle Jurassic marine successions...

CAUSAL RELATIONSHIP BETWEEN FOSSIL FUEL CONSUMPTION AND ECONOMIC GROWTH IN JAPAN: A MULTIVARIATE APPROACH

Directory of Open Access Journals (Sweden)

Hazuki Ishida

2013-01-01

Full Text Available This paper explores whether Japanese economy can continue to grow without extensive dependence on fossil fuels. The paper conducts time series analysis using a multivariate model of fossil fuels, non-fossil energy, labor, stock and GDP to investigate the relationship between fossil fuel consumption and economic growth in Japan. The results of cointegration tests indicate long-run relationships among the variables. Using a vector error-correction model, the study reveals bidirectional causality between fossil fuels and GDP. The results also show that there is no causal relationship between non-fossil energy and GDP. The results of cointegration analysis, Granger causality tests, and variance decomposition analysis imply that non-fossil energy may not necessarily be able to play the role of fossil fuels. Japan cannot seem to realize both continuous economic growth and the departure from dependence on fossil fuels. Hence, growth-oriented macroeconomic policies should be re-examined.

Do fossil vertebrate biominerals hold the key to the Palaeozoic climate?

Science.gov (United States)

Žigaitė, Ž.

2012-04-01

Fossil vertebrate hard tissues - teeth and dermoskeleton - are considered among the most geochemically stable biominerals, and therefore are widely used for palaeoenvironmental and palaeoclimatic reconstructions. Elemental and isotopic compositions of fossil dental tissues may provide unique palaeoenvironmental information, ranging from the diet and trophic positions on a food chain, to the palaeosalinity and water temperatures of ancient seas. However, the post-mortem alteration and re-crystallisation of fossil hard tissues may hamper these interpretations. Chemical composition and isotopic equilibrium of the biomineral change readily at any time from the earliest diagenesis to the final laboratory acid treatment during the fossil preparation. This is why particular attention shall be given to the preservation of fossil tissues, evaluating carefully the level of possible alteration in the primary geochemical composition. Pre-evaluation of fossil preservation can be made by semi-quantitative spot geochemistry analyses on fine polished teeth and scale thin sections using Energy Dispersive X-ray Spectroscopy (EDS), and help to preview the chemical composition of biomineral. The Electron Backscatter Diffractometry (EBSD) is useful to examine the cristallinity and possible structural alterations. In addition, rare earth element (REE) abundances can be measured in situ within the fine fossil tissues (such as enamel) using Laser Ablation Inductively Coupled Plasma Mass-spectrometry (LA-ICP-MS), giving evidence on the selective geochemical resilience between separate vertebrate hard tissues. Therefore, in order to decipher the geochemical signal correctly, the evaluation of preservation is a necessary starting point to any further studies of fossil biomineral geochemistry.

Ancient fossil specimens of extinct species are genetically more distant to an outgroup than extant sister species are

Science.gov (United States)

Huang, Shi

2009-01-01

There exists a remarkable correlation between genetic distance as measured by protein or DNA dissimilarity and time of species divergence as inferred from fossil records. This observation has provoked the molecular clock hypothesis. However, data inconsistent with the hypothesis have steadily accumulated in recent years from studies of extant organisms. Here the published DNA and protein sequences from ancient fossil specimens were examined to see if they would support the molecular clock hypothesis. The hypothesis predicts that ancient specimens cannot be genetically more distant to an outgroup than extant sister species are. Also, two distinct ancient specimens cannot be genetically more distant than their extant sister species are. The findings here do not conform to these predictions. Neanderthals are more distant to chimpanzees and gorillas than modern humans are. Dinosaurs are more distant to frogs than extant birds are. Mastodons are more distant to opossums than other placental mammals are. The genetic distance between dinosaurs and mastodons is greater than that between extant birds and mammals. Therefore, while the molecular clock hypothesis is consistent with some data from extant organisms, it has yet to find support from ancient fossils. Far more damaging to the hypothesis than data from extant organisms, which merely question the constancy of mutation rate, the study of ancient fossil organisms here challenges for the first time the fundamental premise of modern evolution theory that genetic distances had always increased with time in the past history of life on Earth. PMID:18600632

"Small size" in the Philippine human fossil record: is it meaningful for a better understanding of the evolutionary history of the negritos?

Science.gov (United States)

Détroit, Florent; Corny, Julien; Dizon, Eusebio Z; Mijares, Armand S

2013-01-01

"Pygmy populations" are recognized in several places over the world, especially in Western Africa and in Southeast Asia (Philippine "negritos," for instance). Broadly defined as "small-bodied Homo sapiens" (compared with neighboring populations), their origins and the nature of the processes involved in the maintenance of their phenotype over time are highly debated. Major results have been recently obtained from population genetics on present-day negrito populations, but their evolutionary history remains largely unresolved. We present and discuss the Upper Pleistocene human remains recovered from Tabon Cave and Callao Cave in the Philippines, which are potentially highly relevant to these research questions. Human fossils have been recovered in large numbers from Tabon Cave (Palawan Island) but mainly from reworked and mixed sediments from several archaeological layers. We review and synthesize the long and meticulous collaborative work done on the archives left from the 1960s excavations and on the field. The results demonstrate the long history of human occupations in the cave, since at least ~30,000 BP. The examination of the Tabon human remains shows a large variability: large and robust for one part of the sample, and small and gracile for the other part. The latter would fit quite comfortably within the range of variation of Philippine negritos. Farther north, on Luzon Island, the human third metatarsal recently recovered from Callao Cave and dated to ~66,000 BP is now the oldest direct evidence of human presence in the Philippines. Previous data show that, compared with H. sapiens (including Philippine negritos), this bone presents a very small size and several unusual morphological characteristics. We present a new analytical approach using three-dimensional geometric morphometrics for comparing the Callao fossil to a wide array of extant Asian mammals, including nonhuman primates and H. sapiens. The results demonstrate that the shape of the Callao

Microalgal and terrestrial transport biofuels to displace fossil fuels

NARCIS (Netherlands)

Reijnders, L.

2009-01-01

Terrestrial transport biofuels differ in their ability to replace fossil fuels. When both the conversion of solar energy into biomass and the life cycle inputs of fossil fuels are considered, ethanol from sugarcane and biodiesel from palm oil do relatively well, if compared with ethanol from corn,

Magnetostratigraphy of the Fossil-Rich Shungura Formation, southwest Ethiopia

Science.gov (United States)

Kidane, Tesfaye; Brown, Francis H.; Kidney, Casey

2014-09-01

tephrostratigraphic work results in reinterpretation of the stratigraphy suggesting that only the Mammoth Subchron is preserved in the upper part of this formation. In the Shungura, Usno and Koobi Fora formations, the thickness represented by the lower Gauss and Mammoth Subchron is very similar, but the Kaena Subchron is either not recorded in the type area of the Shungura Formation, or only incompletely revealed.

Bizarre tubercles on the vertebrae of Eocene fossil birds indicate an avian disease without modern counterpart

Science.gov (United States)

Mayr, Gerald

2007-08-01

Remains of fossil birds with numerous bony tubercles on the cervical vertebrae are reported from the Middle Eocene of Messel in Germany and the Late Eocene of the Quercy fissure fillings in France. These structures, which are unknown from extant birds and other vertebrates, were previously described for an avian skeleton from Messel but considered a singular feature of this specimen. The new fossils are from a different species of uncertain phylogenetic affinities and show that tuberculated vertebrae have a wider taxonomic, temporal, and geographic distribution. In contrast to previous assumptions, they are no ontogenetic feature and arise from the vertebral surface. It is concluded that they are most likely of pathologic origin and the first record of a Paleogene avian disease. Their regular and symmetrical arrangement over most of the external vertebral surface indicates a systemic disorder caused by factors that do not affect extant birds, such as especially high-dosed phytohormones or extinct pathogens.

Environmental damage caused by fossil fuels consumption

International Nuclear Information System (INIS)

Barbir, F.; Veziroglu, T.N.

1991-01-01

This paper reports that the objectives of this study is to identify the negative effects of the fossil fuels use and to evaluate their economic significance. An economic value of the damage for each of the analyzed effects has been estimated in US dollars per unit energy of the fuel used ($/GJ). This external costs of fossil fuel use should be added to their existing market price, and such real costs should be compared with the real costs of other, environmentally acceptable, energy alternatives, such as hydrogen

Les hominoïdes fossiles : une aide pour l’éducation en Afrique Fossil hominoids: an educational help in Africa

Directory of Open Access Journals (Sweden)

Brigitte Senut

2009-10-01

Full Text Available L’Afrique est un continent privilégié pour décrypter notre histoire partagée avec celle des grands singes et comprendre l’émergence de notre famille en rapport avec l’environnement. Aujourd’hui de nombreuses expéditions  internationales mènent des recherches sur le continent et plus spécialement dans les pays d’Afrique orientale. Le riche patrimoine fossile découvert dans des endroits souvent isolés est transféré dans les musées nationaux, (créés le plus souvent par des expatriés et situés dans les capitales où l’accès y est plus facile pour les chercheurs internationaux, mais souvent difficile voire impossible pour les gens qui habitent près des sites fossilifères. Que se passe-t-il au niveau local ? Le plus souvent, les populations ont été marginalisées, des sentiments de frustration sont apparus, notamment en raison de la grande médiatisation des découvertes de laquelle les locaux sont souvent exclus. Or, ce sont ces populations locales qui sont les gardiennes du patrimoine. Les choses changent progressivement et aujourd’hui, de plus en plus de chercheurs de terrain s’impliquent dans la vie locale et les besoins locaux. Notre engagement de scientifique en tant que citoyen est fondamental : l’éducation est un droit pour tous, comme cela est signalé dans la déclaration universelle des droits de l’homme. Dans le cadre des travaux entrepris en Afrique avec l’équipe, des grands singes et des hominidés fossiles ont été découverts dans trois pays africains sur lesquels cet article est focalisé : l’Ouganda, le Kenya et la Namibie ; ces données montrent que l’évolution des grands singes ne s’est pas déroulée exclusivement en Afrique orientale, mais bien sur l’ensemble du continent, comme cela a été confirmé plus récemment par des découvertes en Afrique centrale et occidentale. Ces découvertes ont été réalisées avec des citoyens de chacun de ces pays et ont donné lieu �

Impact Theory of Mass Extinctions and the Invertebrate Fossil Record

Science.gov (United States)

Alvarez, Walter; Kauffman, Erle G.; Surlyk, Finn; Alvarez, Luis W.; Asaro, Frank; Michel, Helen V.

1984-03-01

There is much evidence that the Cretaceous-Tertiary boundary was marked by a massive meteorite impact. Theoretical consideration of the consequences of such an impact predicts sharp extinctions in many groups of animals precisely at the boundary. Paleontological data clearly show gradual declines in diversity over the last 1 to 10 million years in various invertebrate groups. Reexamination of data from careful studies of the best sections shows that, in addition to undergoing the decline, four groups (ammonites, cheilostomate bryozoans, brachiopods, and bivalves) were affected by sudden truncations precisely at the iridium anomaly that marks the boundary. The paleontological record thus bears witness to terminal-Cretaceous extinctions on two time scales: a slow decline unrelated to the impact and a sharp truncation synchronous with and probably caused by the impact.

Divesting from Fossil Fuels Makes Sense Morally… and Financially

Science.gov (United States)

Cleveland, Cutler J.; Reibstein, Richard

2015-01-01

Should university endowments divest from fossil fuels? A public discussion of this question has seen some university presidents issuing statements that they would not divest--that investments should not be used for "political action." Many universities hold large endowments that have significant positions in fossil fuel companies or…

Fossil butterflies, calibration points and the molecular clock (Lepidoptera: Papilionoidea).

Science.gov (United States)

Jong, Rienk DE

2017-05-25

Fossil butterflies are extremely rare. Yet, they are the only direct evidence of the first appearance of particular characters and as such, they are crucial for calibrating a molecular clock, from which divergence ages are estimated. In turn, these estimates, in combination with paleogeographic information, are most important in paleobiogeographic considerations. The key issue here is the correct allocation of fossils on the phylogenetic tree from which the molecular clock is calibrated.The allocation of a fossil on a tree should be based on an apomorphic character found in a tree based on extant species, similar to the allocation of a new extant species. In practice, the latter is not done, at least not explicitly, on the basis of apomorphy, but rather on overall similarity or on a phylogenetic analysis, which is not possible for most butterfly fossils since they usually are very fragmentary. Characters most often preserved are in the venation of the wings. Therefore, special attention is given to possible apomorphies in venational characters in extant butterflies. For estimation of divergence times, not only the correct allocation of the fossil on the tree is important, but also the tree itself influences the outcome as well as the correct determination of the age of the fossil. These three aspects are discussed.        All known butterfly fossils, consisting of 49 taxa, are critically reviewed and their relationship to extant taxa is discussed as an aid for correctly calibrating a molecular clock for papilionoid Lepidoptera. In this context some aspects of age estimation and biogeographic conclusions are briefly mentioned in review. Specific information has been summarized in four appendices.

Molecular fossils in Cretaceous condensate from western India

Science.gov (United States)

Bhattacharya, Sharmila; Dutta, Suryendu; Dutta, Ratul

2014-06-01

The present study reports the biomarker distribution of condensate belonging to the early Cretaceous time frame using gas chromatography-mass spectrometry (GC-MS). The early Cretaceous palaeoenvironment was inscribed into these molecular fossils which reflected the source and conditions of deposition of the condensate. The saturate fraction of the condensate is characterized by normal alkanes ranging from n-C9 to n-C29 (CPI-1.13), cycloalkanes and C14 and C15 sesquiterpanes. The aromatic fraction comprises of naphthalene, phenanthrene, their methylated derivatives and cyclohexylbenzenes. Isohexylalkylnaphthalenes, a product of rearrangement process of terpenoids, is detected in the condensate. Several aromatic sesquiterpenoids and diterpenoids have been recorded. Dihydro- ar-curcumene, cadalene and ionene form the assemblage of sesquiterpenoids which are indicative of higher plant input. Aromatic diterpenoid fraction comprises of simonellite and retene. These compounds are also indicative of higher plants, particularly conifer source which had been a predominant flora during the Cretaceous time.

Historic Patterns of CO{sub 2} Emissions from Fossil Fuels: Implications for Stabilization of Emissions

Science.gov (United States)

Andres, R. J.; Marland, G.

1994-06-01

This paper examines the historical record of greenhouse gas emissions since 1950, reviews the prospects for emissions into the future, and projects what would be the short-term outcome if the stated targets of the FCCC were in fact achieved. The examination focuses on the most important of the greenhouse gases, CO{sub 2}. The extensive record of historic CO{sub 2} emissions is explored to ascertain if it is an adequate basis for useful extrapolation into the near future. Global carbon dioxide emissions from fossil fuel consumption have been documented. Emissions grew at 4.3% per year from 1950 until the time of the 1973 oil crisis. Another disruption in growth followed the oil price increases of 1979. Global total emissions have been increasing steadily since the 1982-1983 minimum and have grown by more than 20% since then. At present, emission Of CO{sub 2} from fossil fuel burning is dominated by a few countries: the U.S., the former Soviet Union, China, the developed countries of Europe and Japan. Only 20 countries emit 84% of emissions from all countries. However, rates of growth in many of the developed countries are now very low. In contrast, energy use has grown rapidly over the last 20 years in some of the large, developing economies. Emissions from fossil fuel consumption are now nearly 4 times those from land use change and are the primary cause of measured increases in the atmospheric concentration of CO{sub 2}. The increasing concentration of atmospheric CO{sub 2} has led to rising concern about the possibility of impending changes in the global climate system. In an effort to limit or mitigate potential negative effects of global climate change, 154 countries signed the United Nations Framework Convention on Climate Change (FCCC) in Rio de Janeiro in June, 1992. The FCCC asks all countries to conduct an inventory of their current greenhouse gas emissions setting non-binding targets.

Clean fossil-fuelled power generation

International Nuclear Information System (INIS)

Oliver, Tony

2008-01-01

Using fossil fuels is likely to remain the dominant means of producing electricity in 2030 and even 2050, partly because power stations have long lives. There are two main ways of reducing CO 2 emissions from fossil-fuelled power plants. These are carbon capture and storage (CCS), which can produce near-zero CO 2 emissions, and increases in plant efficiency, which can give rise to significant reductions in CO 2 emissions and to reduced costs. If a typical UK coal-fired plant was replaced by today's best available technology, it would lead to reductions of around 25% in emissions of CO 2 per MW h of electricity produced. Future technologies are targeting even larger reductions in emissions, as well as providing a route, with CCS, to zero emissions. These two routes are linked and they are both essential activities on the pathway to zero emissions. This paper focuses on the second route and also covers an additional third route for reducing emissions, the use of biomass. It discusses the current status of the science and technologies for fossil-fuelled power generation and outlines likely future technologies, development targets and timescales. This is followed by a description of the scientific and technological developments that are needed to meet these challenges. Once built, a power plant can last for over 40 years, so the ability to upgrade and retrofit a plant during its lifetime is important

PROTO-PLANETARY DISK CHEMISTRY RECORDED BY D-RICH ORGANIC RADICALS IN CARBONACEOUS CHONDRITES

International Nuclear Information System (INIS)

Remusat, Laurent; Robert, Francois; Meibom, Anders; Mostefaoui, Smail; Delpoux, Olivier; Binet, Laurent; Gourier, Didier; Derenne, Sylvie

2009-01-01

Insoluble organic matter (IOM) in primitive carbonaceous meteorites has preserved its chemical composition and isotopic heterogeneity since the solar system formed ∼4.567 billion years ago. We have identified the carrier moieties of isotopically anomalous hydrogen in IOM isolated from the Orgueil carbonaceous chondrite. Data from high spatial resolution, quantitative isotopic NanoSIMS mapping of Orgueil IOM combined with data from electron paramagnetic resonance spectroscopy reveals that organic radicals hold all the deuterium excess (relative to the bulk IOM) in distinct, micrometer-sized, D-rich hotspots. Taken together with previous work, the results indicate that an isotopic exchange reaction took place between pre-existing organic compounds characterized by low D/H ratios and D-rich gaseous molecules, such as H 2 D + or HD 2 + . This exchange reaction most likely took place in the diffuse outer regions of the proto-planetary disk around the young Sun, offering a model that reconciles meteoritic and cometary isotopic compositions of organic molecules.

Proto-Planetary Disk Chemistry Recorded by D-Rich Organic Radicals in Carbonaceous Chondrites

Science.gov (United States)

Remusat, Laurent; Robert, François; Meibom, Anders; Mostefaoui, Smail; Delpoux, Olivier; Binet, Laurent; Gourier, Didier; Derenne, Sylvie

2009-06-01

Insoluble organic matter (IOM) in primitive carbonaceous meteorites has preserved its chemical composition and isotopic heterogeneity since the solar system formed ~4.567 billion years ago. We have identified the carrier moieties of isotopically anomalous hydrogen in IOM isolated from the Orgueil carbonaceous chondrite. Data from high spatial resolution, quantitative isotopic NanoSIMS mapping of Orgueil IOM combined with data from electron paramagnetic resonance spectroscopy reveals that organic radicals hold all the deuterium excess (relative to the bulk IOM) in distinct, micrometer-sized, D-rich hotspots. Taken together with previous work, the results indicate that an isotopic exchange reaction took place between pre-existing organic compounds characterized by low D/H ratios and D-rich gaseous molecules, such as H2D+ or HD2 +. This exchange reaction most likely took place in the diffuse outer regions of the proto-planetary disk around the young Sun, offering a model that reconciles meteoritic and cometary isotopic compositions of organic molecules.

Fossil energy research meeting

Energy Technology Data Exchange (ETDEWEB)

Kropschot, R. H.; Phillips, G. C.

1977-12-01

U.S. ERDA's research programs in fossil energy are reviewed with brief descriptions, budgets, etc. Of general interest are discussions related to the capabilities for such research of national laboratories, universities, energy centers, etc. Of necessity many items are treated briefly, but a general overview of the whole program is provided. (LTN)

Influence of fossil energy applications on environmental pollution

Energy Technology Data Exchange (ETDEWEB)

Balat, M.; Ayar, G.; Oguzhan, C.; Uluduz, H.; Faiz, U. [University of Mahallesi, Trabzon (Turkey)

2007-07-01

The aim of this work is to investigate influence of fossil energy applications on the environmental pollution. Turkey's high rate of economic growth experienced during much of the 1990s, besides resulting in booming industrial production, also led to higher levels of energy consumption, imports, air and water pollution, and greater risks to the country's environment. Air pollution is a major problem in Turkey, with key pollutants including sulfur dioxide, suspended particulates, nitrogen oxides, and carbon dioxide. In Turkey, carbon dioxide emissions from fossil fuels totaled about 50.07 million tons in 2001. However, fuel share of carbon emissions in 2001 was oil 44.2%, coal 38.8%, and natural gas 16.9%. Total carbon dioxide emissions from fossil fuels are expected to be 104 million tons in 2025.

Common species link global ecosystems to climate change: dynamical evidence in the planktonic fossil record.

Science.gov (United States)

Hannisdal, Bjarte; Haaga, Kristian Agasøster; Reitan, Trond; Diego, David; Liow, Lee Hsiang

2017-07-12

Common species shape the world around us, and changes in their commonness signify large-scale shifts in ecosystem structure and function. However, our understanding of long-term ecosystem response to environmental forcing in the deep past is centred on species richness, neglecting the disproportional impact of common species. Here, we use common and widespread species of planktonic foraminifera in deep-sea sediments to track changes in observed global occupancy (proportion of sampled sites at which a species is present and observed) through the turbulent climatic history of the last 65 Myr. Our approach is sensitive to relative changes in global abundance of the species set and robust to factors that bias richness estimators. Using three independent methods for detecting causality, we show that the observed global occupancy of planktonic foraminifera has been dynamically coupled to past oceanographic changes captured in deep-ocean temperature reconstructions. The causal inference does not imply a direct mechanism, but is consistent with an indirect, time-delayed causal linkage. Given the strong quantitative evidence that a dynamical coupling exists, we hypothesize that mixotrophy (symbiont hosting) may be an ecological factor linking the global abundance of planktonic foraminifera to long-term climate changes via the relative extent of oligotrophic oceans. © 2017 The Authors.

Testing the molecular clock using mechanistic models of fossil preservation and molecular evolution.

Science.gov (United States)

Warnock, Rachel C M; Yang, Ziheng; Donoghue, Philip C J

2017-06-28

Molecular sequence data provide information about relative times only, and fossil-based age constraints are the ultimate source of information about absolute times in molecular clock dating analyses. Thus, fossil calibrations are critical to molecular clock dating, but competing methods are difficult to evaluate empirically because the true evolutionary time scale is never known. Here, we combine mechanistic models of fossil preservation and sequence evolution in simulations to evaluate different approaches to constructing fossil calibrations and their impact on Bayesian molecular clock dating, and the relative impact of fossil versus molecular sampling. We show that divergence time estimation is impacted by the model of fossil preservation, sampling intensity and tree shape. The addition of sequence data may improve molecular clock estimates, but accuracy and precision is dominated by the quality of the fossil calibrations. Posterior means and medians are poor representatives of true divergence times; posterior intervals provide a much more accurate estimate of divergence times, though they may be wide and often do not have high coverage probability. Our results highlight the importance of increased fossil sampling and improved statistical approaches to generating calibrations, which should incorporate the non-uniform nature of ecological and temporal fossil species distributions. © 2017 The Authors.

A synthesis of carbon dioxide emissions from fossil-fuel combustion

DEFF Research Database (Denmark)

Andres, R.J.; Boden, T.A.; Bréon, F.-M.

2012-01-01

This synthesis discusses the emissions of carbon dioxide from fossil-fuel combustion and cement production. While much is known about these emissions, there is still much that is unknown about the details surrounding these emissions. This synthesis explores our knowledge of these emissions in terms......; and the uncertainties associated with these different aspects of the emissions. The magnitude of emissions from the combustion of fossil fuels has been almost continuously increasing with time since fossil fuels were first used by humans. Despite events in some nations specifically designed to reduce emissions......, or which have had emissions reduction as a byproduct of other events, global total emissions continue their general increase with time. Global total fossilfuel carbon dioxide emissions are known to within 10% uncertainty (95% confidence interval). Uncertainty on individual national total fossil-fuel carbon...

Potential high temperature corrosion problems due to co-firing of biomass and fossil fuels

DEFF Research Database (Denmark)

Montgomery, Melanie; Vilhelmsen, T.; Jensen, S.A.

2007-01-01

Over the past years, considerable high temperature corrosion problems have been encountered when firing biomass in power plants due to the high content of potassium chloride in the deposits. Therefore to combat chloride corrosion problems co-firing of biomass with a fossil fuel has been undertaken....... This results in potassium chloride being converted to potassium sulphate in the combustion chamber and it is sulphate rich deposits that are deposited on the vulnerable metallic surfaces such as high temperature superheaters. Although this removes the problem of chloride corrosion, other corrosion mechanisms...... appear such as sulphidation and hot corrosion due to sulphate deposits. At Studstrup power plant Unit 4, based on trials with exposure times of 3000 hours using 0-20% straw co-firing with coal, the plant now runs with a fuel of 10% straw + coal. After three years exposure in this environment...

Express delivery of fossil meteorites from the inner asteroid belt to Sweden

Science.gov (United States)

Nesvorný, David; Vokrouhlický, David; Bottke, William F.; Gladman, Brett; Häggström, Therese

2007-06-01

Our understanding of planet formation depends in fundamental ways on what we learn by analyzing the composition, mineralogy, and petrology of meteorites. Yet, it is difficult to deduce the compositional and thermal gradients that existed in the solar nebula from the meteoritic record because, in most cases, we do not know where meteorites with different chemical and isotopic signatures originated. Here we developed a model that tracks the orbits of meteoroid-sized objects as they evolve from the ν secular resonance to Earth-crossing orbits. We apply this model to determining the number of meteorites accreted on the Earth immediately after a collisional disruption of a D˜200-km-diameter inner-main-belt asteroid in the Flora family region. We show that this event could produce fossil chondrite meteorites found in an ≈470 Myr old marine limestone quarry in southern Sweden, the L-chondrite meteorites with shock ages ≈470 Myr falling on the Earth today, as well as asteroid-sized fragments in the Flora family. To explain the measured short cosmic-ray exposure ages of fossil meteorites our model requires that the meteoroid-sized fragments were launched at speeds >500 m s -1 and/or the collisional lifetimes of these objects were much shorter immediately after the breakup event than they are today.

Loops formed by tidal tails as fossil records of a major merger

Science.gov (United States)

Wang, J.; Hammer, F.; Athanassoula, E.; Puech, M.; Yang, Y.; Flores, H.

2012-02-01

Context. Many haloes of nearby disc galaxies contain faint and extended features, including loops, which are often interpreted as relics of satellite infall in the main galaxy's potential well. In most cases, however, the residual nucleus of the satellite is not seen, although it is predicted by numerical simulations. Aims: We test whether such faint and extended features can be associated to gas-rich, major mergers, which may also lead to disc rebuilding and thus be a corner stone for the formation of spiral galaxies. Our goal is to test whether the major merger scenario can provide a good model for a particularly difficult case, that of NGC 5907, and to compare to the scenario of a satellite infall. Methods: Using the TreeSPH code GADGET-2, we model the formation of an almost bulge-less galaxy similar to NGC 5907 (B/T ≲ 0.2) after a gas-rich major merger. First, we trace tidal tail particles captured by the galaxy gravitational potential to verify whether they can form loops similar to those discovered in the galactic haloes. Results: We indeed find that 3:1 major mergers can form features similar to the loops found in many galactic haloes, including in NGC 5907, and can reproduce an extended thin disc, a bulge, as well as the pronounced warp of the gaseous disc. Relatively small bulge fractions can be reproduced by a large gas fraction in the progenitors, as well as appropriate orbital parameters. Conclusions: Even though it remains difficult to fully cover the large volume of free parameters, the present modelling of the loops in NGC 5907 proves that they could well be the result of a major merger. It has many advantages over the satellite infall scenario; e.g., it solves the problem of the visibility of the satellite remnant, and it may explain some additional features in the NGC 5907 halo, as well as some gas properties of this system. For orbital parameters derived from cosmological simulations, the loops in NGC 5907 can be reproduced by major mergers (3

Arthropods in modern resins reveal if amber accurately recorded forest arthropod communities.

Science.gov (United States)

Solórzano Kraemer, Mónica M; Delclòs, Xavier; Clapham, Matthew E; Arillo, Antonio; Peris, David; Jäger, Peter; Stebner, Frauke; Peñalver, Enrique

2018-05-07

Amber is an organic multicompound derivative from the polymerization of resin of diverse higher plants. Compared with other modes of fossil preservation, amber records the anatomy of and ecological interactions between ancient soft-bodied organisms with exceptional fidelity. However, it is currently suggested that ambers do not accurately record the composition of arthropod forest paleocommunities, due to crucial taphonomic biases. We evaluated the effects of taphonomic processes on arthropod entrapment by resin from the plant Hymenaea , one of the most important resin-producing trees and a producer of tropical Cenozoic ambers and Anthropocene (or subfossil) resins. We statistically compared natural entrapment by Hymenaea verrucosa tree resin with the ensemble of arthropods trapped by standardized entomological traps around the same tree species. Our results demonstrate that assemblages in resin are more similar to those from sticky traps than from malaise traps, providing an accurate representation of the arthropod fauna living in or near the resiniferous tree, but not of entire arthropod forest communities. Particularly, arthropod groups such as Lepidoptera, Collembola, and some Diptera are underrepresented in resins. However, resin assemblages differed slightly from sticky traps, perhaps because chemical compounds in the resins attract or repel specific insect groups. Ground-dwelling or flying arthropods that use the tree-trunk habitat for feeding or reproduction are also well represented in the resin assemblages, implying that fossil inclusions in amber can reveal fundamental information about biology of the past. These biases have implications for the paleoecological interpretation of the fossil record, principally of Cenozoic amber with angiosperm origin.

The phylogeny of fossil whip spiders.

Science.gov (United States)

Garwood, Russell J; Dunlop, Jason A; Knecht, Brian J; Hegna, Thomas A

2017-04-21

Arachnids are a highly successful group of land-dwelling arthropods. They are major contributors to modern terrestrial ecosystems, and have a deep evolutionary history. Whip spiders (Arachnida, Amblypygi), are one of the smaller arachnid orders with ca. 190 living species. Here we restudy one of the oldest fossil representatives of the group, Graeophonus anglicus Pocock, 1911 from the Late Carboniferous (Duckmantian, ca. 315 Ma) British Middle Coal Measures of the West Midlands, UK. Using X-ray microtomography, our principal aim was to resolve details of the limbs and mouthparts which would allow us to test whether this fossil belongs in the extant, relict family Paracharontidae; represented today by a single, blind species Paracharon caecus Hansen, 1921. Tomography reveals several novel and significant character states for G. anglicus; most notably in the chelicerae, pedipalps and walking legs. These allowed it to be scored into a phylogenetic analysis together with the recently described Paracharonopsis cambayensis Engel & Grimaldi, 2014 from the Eocene (ca. 52 Ma) Cambay amber, and Kronocharon prendinii Engel & Grimaldi, 2014 from Cretaceous (ca. 99 Ma) Burmese amber. We recovered relationships of the form ((Graeophonus (Paracharonopsis + Paracharon)) + (Charinus (Stygophrynus (Kronocharon (Charon (Musicodamon + Paraphrynus)))))). This tree largely reflects Peter Weygoldt's 1996 classification with its basic split into Paleoamblypygi and Euamblypygi lineages; we were able to score several of his characters for the first time in fossils. Our analysis draws into question the monophyly of the family Charontidae. Our data suggest that Graeophonus is a crown group amblypygid, and falls within a monophyletic Paleoamblypgi clade, but outside the family Paracharontidae (= Paracharonopsis + Paracharon). Our results also suggest a new placement for the Burmese amber genus Kronocharon, a node further down from its original position. Overall, we offer a

First record of Annonaceae wood for the Neogene of South America, Amazon Basin, Brazil

Directory of Open Access Journals (Sweden)

Emilio Alberto Amaral Soares

Full Text Available ABSTRACT: The relief of the regions of Manaus and Itacoatiara, Central Amazon, is supported by Neogene siliciclastic rocks, bounded at the base and top by lateritic paleosols and covered by quaternary sedimentary deposits from the Solimões-Amazon river system. This unit is informally assigned to the Novo Remanso Formation, consists of usually reddish and ferruginized sandstones, conglomerates and pelites, with few identified fossil records, a fact that has hindered its stratigraphic position, and the paleoenvironmental reconstruction of the last phase of the Amazon Basin settling. This study describes, for the first time, the occurrence of fossil wood in outcroppings of the left bank of the Amazon River, where anatomical and morphological data has enabled its characterization to the species level. Thus, the data marks the record of the Annonaceae in South America, as well as the depositional processes related to incorporation of organic material in the sandy layer and the fossilization processes that allowed its preservation. In an unprecedented way, this study has described Duguetiaxylon amazonicum nov. gen and sp. and provided information on the anatomical and systematic character, as well as data on plant-insect interaction, and a better understanding of the family.

Improving large-scale groundwater models by considering fossil gradients

Science.gov (United States)

Schulz, Stephan; Walther, Marc; Michelsen, Nils; Rausch, Randolf; Dirks, Heiko; Al-Saud, Mohammed; Merz, Ralf; Kolditz, Olaf; Schüth, Christoph

2017-05-01

Due to limited availability of surface water, many arid to semi-arid countries rely on their groundwater resources. Despite the quasi-absence of present day replenishment, some of these groundwater bodies contain large amounts of water, which was recharged during pluvial periods of the Late Pleistocene to Early Holocene. These mostly fossil, non-renewable resources require different management schemes compared to those which are usually applied in renewable systems. Fossil groundwater is a finite resource and its withdrawal implies mining of aquifer storage reserves. Although they receive almost no recharge, some of them show notable hydraulic gradients and a flow towards their discharge areas, even without pumping. As a result, these systems have more discharge than recharge and hence are not in steady state, which makes their modelling, in particular the calibration, very challenging. In this study, we introduce a new calibration approach, composed of four steps: (i) estimating the fossil discharge component, (ii) determining the origin of fossil discharge, (iii) fitting the hydraulic conductivity with a pseudo steady-state model, and (iv) fitting the storage capacity with a transient model by reconstructing head drawdown induced by pumping activities. Finally, we test the relevance of our approach and evaluated the effect of considering or ignoring fossil gradients on aquifer parameterization for the Upper Mega Aquifer (UMA) on the Arabian Peninsula.

Macro fossils vegetable in Palmar formation (later pleistocene) in Entre Rios - Argentina

International Nuclear Information System (INIS)

Ramos, R.; Brea, M.; Krohling, D.

2012-01-01

This work is about the macro fossil knowledge preserved like wood fossils in the El Palmar Formation (Late Pleistocene) from a systematic - anatomical as well as paleoecological and paleoclimate point of view.The paleo Flora comes from various fossil located in the province of Entre Rios - Argentina

Early cave art and ancient DNA record the origin of European bison

DEFF Research Database (Denmark)

Soubrier, Julien; Gower, Graham; Chen, Kefei

2016-01-01

The two living species of bison (European and American) are among the few terrestrial megafauna to have survived the late Pleistocene extinctions. Despite the extensive bovid fossil record in Eurasia, the evolutionary history of the European bison (or wisent, Bison bonasus) before the Holocene (<...

Fossil Fuel Industry Funding of Climate-Relevant Research at U.S. Universities

Science.gov (United States)

Franta, B.; Supran, G.

2017-12-01

Commercial producers of lead, tobacco, petroleum, and other products have funded extensive scholarly research in ways designed to confuse the public about the dangers of those products and thwart regulation [1-3]. For example, strategy documentation of the U.S. oil and gas industry from the late 1990s describes using selective support for scientists as a strategy for creating an atmosphere of debate and uncertainty, with the ultimate goal of delaying and defeating climate policies [4]. In this context, we systematically examine current funding from commercial fossil fuel interests of climate-relevant research - such as energy technology and climate policy research - in U.S. universities. We quantify such funding using charitable giving databases, university websites, and other publicly available records. We find that, especially among the most influential universities, climate-related research programs are frequently dominated by funding from fossil fuel interests. Moreover, these relationships sometimes afford funders privileges including formal control over research directions. This work represents an advance in mapping the presence of commercial fossil fuel interests in academia and may contribute to discussions of appropriate funding systems for climate-relevant research. 1. Markowitz, G. and D. Rosner, Lead Wars: The Politics of Science and the Fate of America's Children. 1st ed. 2013: University of California Press. 2. Brandt, A.M., Inventing Conflicts of Interest: A History of Tobacco Industry Tactics. American Journal of Public Health, 2012. 102(1): p. 63-71. 3. Oreskes, N. and E.M. Conway, Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming. 2011: Bloomsbury Press. 4. Walker, J., Global Climate Science Communications Action Plan. 1998. Workshop held at the headquarters of the American Petroleum Institute.

On the identity of the fossil hydrophilid beetles from the Tertiary localities in the southern part of the Upper Rhine Graben (Coleoptera: Hydrophilidae, Dytiscidae

Directory of Open Access Journals (Sweden)

Martin Fikácek

2011-01-01

Full Text Available This study focuses on the beetles from the Oligocene localities in the southern part of the Upper Rhine Graben (Brunstatt: France, Alsace; and Kleinkems: Germany, Baden-Württemberg assigned to the family Hydrophilidae by previous authors. The identity of Escheria convexa Förster, 1891 is fixed by the designation of its neotype, the species is redescribed, illustrated and transferred from the hydrophilid genus Hydrobius Leach, 1815 to the genus Copelatus Erichson, 1832 (Coleoptera: Adephaga: Dytiscidae and compared with other fossil representatives of Copelatus. The identity of the remaining three species is briefly evaluated on the basis of the original descriptions and illustrations only, because their types were lost or destroyed during World War II; all three species are removed from the fossil record of the Hydrophiloidea and placed into Polyphaga incertae sedis. The geology and stratigraphy of both fossil outcrops is discussed briefly.

A synthesis of carbon dioxide emissions from fossil-fuel combustion

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R. J. Andres

2012-05-01

Full Text Available This synthesis discusses the emissions of carbon dioxide from fossil-fuel combustion and cement production. While much is known about these emissions, there is still much that is unknown about the details surrounding these emissions. This synthesis explores our knowledge of these emissions in terms of why there is concern about them; how they are calculated; the major global efforts on inventorying them; their global, regional, and national totals at different spatial and temporal scales; how they are distributed on global grids (i.e., maps; how they are transported in models; and the uncertainties associated with these different aspects of the emissions. The magnitude of emissions from the combustion of fossil fuels has been almost continuously increasing with time since fossil fuels were first used by humans. Despite events in some nations specifically designed to reduce emissions, or which have had emissions reduction as a byproduct of other events, global total emissions continue their general increase with time. Global total fossil-fuel carbon dioxide emissions are known to within 10 % uncertainty (95 % confidence interval. Uncertainty on individual national total fossil-fuel carbon dioxide emissions range from a few percent to more than 50 %. This manuscript concludes that carbon dioxide emissions from fossil-fuel combustion continue to increase with time and that while much is known about the overall characteristics of these emissions, much is still to be learned about the detailed characteristics of these emissions.

Fossil energy savings potential of sugar cane bio-energy systems

DEFF Research Database (Denmark)

Nguyen, Thu Lan T; Hermansen, John Erik; Sagisaka, Masayuki

2009-01-01

One important rationale for bio-energy systems is their potential to save fossil energy. Converting a conventional sugar mill into a bio-energy process plant would contribute to fossil energy savings via the extraction of renewable electricity and ethanol substituting for fossil electricity...... and gasoline, respectively. This paper takes a closer look at the Thai sugar industry and examines two practical approaches that will enhance fossil energy savings. The first one addresses an efficient extraction of energy in the form of electricity from the excess bagasse and cane trash. The second while...... proposing to convert molasses or sugar cane to ethanol stresses the use of bagasse as well as distillery spent wash to replace coal in meeting ethanol plants' energy needs. The savings potential achieved with extracting ethanol from surplus sugar versus current practice in sugar industry in Thailand amounts...

Phylogenetic analysis of pelecaniformes (aves based on osteological data: implications for waterbird phylogeny and fossil calibration studies.

Directory of Open Access Journals (Sweden)

Nathan D Smith

2010-10-01

Full Text Available Debate regarding the monophyly and relationships of the avian order Pelecaniformes represents a classic example of discord between morphological and molecular estimates of phylogeny. This lack of consensus hampers interpretation of the group's fossil record, which has major implications for understanding patterns of character evolution (e.g., the evolution of wing-propelled diving and temporal diversification (e.g., the origins of modern families. Relationships of the Pelecaniformes were inferred through parsimony analyses of an osteological dataset encompassing 59 taxa and 464 characters. The relationships of the Plotopteridae, an extinct family of wing-propelled divers, and several other fossil pelecaniforms (Limnofregata, Prophaethon, Lithoptila, ?Borvocarbo stoeffelensis were also assessed. The antiquity of these taxa and their purported status as stem members of extant families makes them valuable for studies of higher-level avian diversification.Pelecaniform monophyly is not recovered, with Phaethontidae recovered as distantly related to all other pelecaniforms, which are supported as a monophyletic Steganopodes. Some anatomical partitions of the dataset possess different phylogenetic signals, and partitioned analyses reveal that these discrepancies are localized outside of Steganopodes, and primarily due to a few labile taxa. The Plotopteridae are recovered as the sister taxon to Phalacrocoracoidea, and the relationships of other fossil pelecaniforms representing key calibration points are well supported, including Limnofregata (sister taxon to Fregatidae, Prophaethon and Lithoptila (successive sister taxa to Phaethontidae, and ?Borvocarbo stoeffelensis (sister taxon to Phalacrocoracidae. These relationships are invariant when 'backbone' constraints based on recent avian phylogenies are imposed.Relationships of extant pelecaniforms inferred from morphology are more congruent with molecular phylogenies than previously assumed, though

Refining of fossil resin flotation concentrate from western coal. Final report

Energy Technology Data Exchange (ETDEWEB)

Jensen, G.F.; Miller, J.D.

1995-02-16

During the past several years, significant research efforts have been made to develop process technology for the selective flotation of fossil resin from western coals. As a result of these efforts, several new flotation technologies have been developed. Operation of a proof-of-concept continuous flotation circuit showed the selective flotation process to be sufficiently profitable to justify the development of a fossil resin industry. However, little attention has been given to the refining of the fossil resin flotation concentrate although solvent refining is a critical step for the fossil resin to become a marketable product. In view of this situation, DOE funded this two-year project to evaluate the following aspects of the fossil resin refining technology: 1) Characterization of the fossil resin flotation concentrate and its refined products; 2) Kinetics of fossil resin extraction; 3) Effects of operating variables on solvent extraction; 4) Extraction solvents; 5) Proof-of-concept continuous refining tests; and 6) Technical and economic analysis. The results from this research effort have led to the following conclusions: Hexane- or heptane-refined fossil resin has a light-yellow color, a melting point of 140 - 142{degrees}C, a density of 1.034 gram/cm, and good solubility in nonpolar solvents. Among the four solvents evaluated (hexane, heptane, toluene and ethyl acetate), hexane is the most appropriate solvent based on overall technical and economic considerations. Batch extraction tests and kinetic studies suggest that the main interaction between the resin and the solvent is expected to be the forces associated with solvation phenomena. Temperature has the most significant effect on extraction rate. With hexane as the solvent, a recovery of 90% cam be achieved at 50{degrees}C and 10% solids concentration with moderate agitation for 1 hour.

The global environment effects of fossil and nuclear fuels

International Nuclear Information System (INIS)

Kemeny, L.G.

1981-01-01

The relative risks and environmental impacts of coal and uranium fueled power plants are dicussed. Fossil-fuel power plants are associated with a build-up of carbon dioxide levels and consequent climatic changes, release of sulphur dioxide and resultant acid rains and radioactive emissions. In comparing the discharges per megawatt year of sulphur dioxide, nitrogen dioxide and radioactive Ra-226 and Ra-225 in fly ash from coal and other fossil plants with Kr-85 and I-131 from nuclear plants, the fossil plants have a much poorer performance. Estimates indicate that nuclear energy can be adopted on a large scale as an alternative to coal without any increase in hazards and with a probability of a substantial reduction

Empirical and Bayesian approaches to fossil-only divergence times: A study across three reptile clades.

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Turner, Alan H; Pritchard, Adam C; Matzke, Nicholas J

2017-01-01

Estimating divergence times on phylogenies is critical in paleontological and neontological studies. Chronostratigraphically-constrained fossils are the only direct evidence of absolute timing of species divergence. Strict temporal calibration of fossil-only phylogenies provides minimum divergence estimates, and various methods have been proposed to estimate divergences beyond these minimum values. We explore the utility of simultaneous estimation of tree topology and divergence times using BEAST tip-dating on datasets consisting only of fossils by using relaxed morphological clocks and birth-death tree priors that include serial sampling (BDSS) at a constant rate through time. We compare BEAST results to those from the traditional maximum parsimony (MP) and undated Bayesian inference (BI) methods. Three overlapping datasets were used that span 250 million years of archosauromorph evolution leading to crocodylians. The first dataset focuses on early Sauria (31 taxa, 240 chars.), the second on early Archosauria (76 taxa, 400 chars.) and the third on Crocodyliformes (101 taxa, 340 chars.). For each dataset three time-calibrated trees (timetrees) were calculated: a minimum-age timetree with node ages based on earliest occurrences in the fossil record; a 'smoothed' timetree using a range of time added to the root that is then averaged over zero-length internodes; and a tip-dated timetree. Comparisons within datasets show that the smoothed and tip-dated timetrees provide similar estimates. Only near the root node do BEAST estimates fall outside the smoothed timetree range. The BEAST model is not able to overcome limited sampling to correctly estimate divergences considerably older than sampled fossil occurrence dates. Conversely, the smoothed timetrees consistently provide node-ages far older than the strict dates or BEAST estimates for morphologically conservative sister-taxa when they sit on long ghost lineages. In this latter case, the relaxed-clock model appears to

Empirical and Bayesian approaches to fossil-only divergence times: A study across three reptile clades.

Directory of Open Access Journals (Sweden)

Alan H Turner

Full Text Available Estimating divergence times on phylogenies is critical in paleontological and neontological studies. Chronostratigraphically-constrained fossils are the only direct evidence of absolute timing of species divergence. Strict temporal calibration of fossil-only phylogenies provides minimum divergence estimates, and various methods have been proposed to estimate divergences beyond these minimum values. We explore the utility of simultaneous estimation of tree topology and divergence times using BEAST tip-dating on datasets consisting only of fossils by using relaxed morphological clocks and birth-death tree priors that include serial sampling (BDSS at a constant rate through time. We compare BEAST results to those from the traditional maximum parsimony (MP and undated Bayesian inference (BI methods. Three overlapping datasets were used that span 250 million years of archosauromorph evolution leading to crocodylians. The first dataset focuses on early Sauria (31 taxa, 240 chars., the second on early Archosauria (76 taxa, 400 chars. and the third on Crocodyliformes (101 taxa, 340 chars.. For each dataset three time-calibrated trees (timetrees were calculated: a minimum-age timetree with node ages based on earliest occurrences in the fossil record; a 'smoothed' timetree using a range of time added to the root that is then averaged over zero-length internodes; and a tip-dated timetree. Comparisons within datasets show that the smoothed and tip-dated timetrees provide similar estimates. Only near the root node do BEAST estimates fall outside the smoothed timetree range. The BEAST model is not able to overcome limited sampling to correctly estimate divergences considerably older than sampled fossil occurrence dates. Conversely, the smoothed timetrees consistently provide node-ages far older than the strict dates or BEAST estimates for morphologically conservative sister-taxa when they sit on long ghost lineages. In this latter case, the relaxed

Recalibrating Equus evolution using the genome sequence of an early Middle Pleistocene horse

DEFF Research Database (Denmark)

Orlando, Ludovic Antoine Alexandre; Ginolhac, Aurélien; Zhang, Guojie

2013-01-01

The rich fossil record of equids has made them a model for evolutionary processes. Here we present a 1.12-times coverage draft genome from a horse bone recovered from permafrost dated to approximately 560-780 thousand years before present (kyr bp). Our data represent the oldest full genome sequen...

Perseverance of pikas in the Miocene : Interplay of climate and competition in the evolution of Spanish Ochotonidae (Lagomorpha, Mammalia). Geologica Ultraiectina (333)

NARCIS (Netherlands)

Hordijk, K.

2010-01-01

The sedimentary succession near the village of Villafeliche in the Calatayud-Montalbán Basin (Spain) is well known for its very rich, densely sampled and well dated fossil mammal record of Miocene age and roughly spans the time interval between 17 and 10 million years ago. The exceptional quality of

Material Flow Analysis of Fossil Fuels in China during 2000–2010

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Wang, Sheng; Dai, Jing; Su, Meirong

2012-01-01

Since the relationship between the supply and demand of fossil fuels is on edge in the long run, the contradiction between the economic growth and limited resources will hinder the sustainable development of the Chinese society. This paper aims to analyze the input of fossil fuels in China during 2000–2010 via the material flow analysis (MFA) that takes hidden flows into account. With coal, oil, and natural gas quantified by MFA, three indexes, consumption and supply ratio (C/S ratio), resource consumption intensity (RCI), and fossil fuels productivity (FFP), are proposed to reflect the interactions between population, GDP, and fossil fuels. The results indicated that in the past 11 years, China's requirement for fossil fuels has been increasing continuously because of the growing mine productivity in domestic areas, which also leads to a single energy consumption structure as well as excessive dependence on the domestic exploitation. It is advisable to control the fossil fuels consumption by energy recycling and new energy facilities' popularization in order to lead a sustainable access to nonrenewable resources and decrease the soaring carbon emissions. PMID:23365525

Impacts of curatorial and research practices on the preservation of fossil hominid remains.

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Le Cabec, Adeline; Toussaint, Michel

2017-12-30

Fossil remains are the only physical evidence of past forms of life which researchers can use to study the evolutionary biology of a species, especially regarding the human lineage. We review and consider the way in which the conditions surrounding a fossil's discovery and its use for scientific research impacts its long-term preservation. The deterioration of the body starts soon after death, continues in the sediments and only a subsample of the anatomical elements will persist and may finally be unearthed by archeologists. From their recovery onwards, fossil remains are exposed to many sources of further damage: from handling, restoration, measuring to invasive sampling. On the one hand, curators are faced with the inherent challenge of balancing their responsibility to protect fossil specimens with allowing researchers to perform specific analyses or invasive sampling detrimental to the preservation of the fossil. On the other hand, scientists may find their analyses complicated by multiple factors including taphonomy, or restoration techniques (e.g., consolidants, cleaning chemicals). We provide several historical examples illustrating the complex nature of the factors acting on fossil preservation. We discuss concerns about producing and sharing (digital) data from fossils. Finally, we also suggest and support some curatorial practices which maximize the traceability of treatments underwent by a fossil.