Swerczek, Thomas W
CASE DESCRIPTION Unexplained clinical signs of weight loss and emaciation were reported in a herd of Thoroughbred horses grazing spring pastures on a central Kentucky farm, even though supplemental grain and hay were provided. CLINICAL FINDINGS A buttercup plant, Ranunculus bulbosus L, was abundantly present in all pastures and paddocks on the farm. All horses, especially lactating mares and their foals, had mild to severe weight loss as assessed by body condition. Seven mares on the farm had been confirmed pregnant between 30 and 45 days of gestation, but were later found to have aborted. Two 2-year-old fillies developed severe diarrhea, incoordination, recumbency, and paralysis and were euthanized. Necropsy of these horses revealed ulcers and erosions in the stomach and large intestine. The findings were considered consistent with buttercup toxicosis. TREATMENT AND OUTCOME The horses were moved from the buttercup-infested pastures to a farm free of the weed. All horses made an uneventful recovery, and clinical signs resolved after the horses were transferred to buttercup-free pastures. Mares that had aborted conceived successfully in the next breeding season. CLINICAL RELEVANCE The buttercup plant is toxic for all classes of livestock. The clinical signs associated with buttercup toxicosis may mimic other disease syndromes affecting the gastrointestinal tract of herbivores. On-farm epidemiological investigations are an essential part of the diagnosis of this condition. Consumption of buttercups has previously been associated with abortions in cattle, but to the author's knowledge, this has not previously been described in horses. PMID:26953921
Kelch, W J; Kerr, L A; Adair, H S; Boyd, G D
A presumptive diagnosis of buttercup toxicosis with photosensitization secondary to hepatotoxicity was made in an 18-mo-old Charolais heifer. The differential diagnosis included salmonellosis, aflatoxicosis, bovine virus diarrhea, internal parasite infestation, and plant toxicosis with either primary or secondary photosensitization. All these possibilities were excluded except buttercup toxicosis with photosensitization secondary to hepatotoxicity. While this diagnosis was not absolutely confirmed, it was the most likely cause of the disease and raised the intriguing possibility that protoanemonin, buttercup's toxic principle, is hepatotoxic. PMID:1609496
Cavanagh, Andrew F; Adler, Lynn S; Hazzard, Ruth V
Winter squash is a vital agricultural commodity worldwide. In the Northeastern United States, the primary insect pest is the striped cucumber beetle, Acalymma vittatum F. Using a Blue Hubbard squash (Cucurbita maxima Duchesne) perimeter trap crop system can reduce insecticide use by >90% in butternut squash (C. moschata Poir), the primary winter squash grown in this region. Despite the savings in insecticide costs, growers may be reluctant to give up field space for a perimeter crop of Blue Hubbard squash, which comprises only 5% of the winter squash market in New England as compared with 19% for buttercup squash. Finding a more marketable trap crop would lower the barrier for adoption of this system. We tested eight varieties of three species of cucurbits for attractiveness to beetles relative to Blue Hubbard and butternut squash, and chose buttercup squash as the most promising replacement. We compared the effect of a buttercup border, Blue Hubbard border, or control (no border) on beetle numbers, herbivory, insecticide use, pollination, and pollen limitation in the main crop. We found that buttercup squash performed equally well as Blue Hubbard as a trap crop, with 97% reduction in total insecticide use compared with control fields. Honey bees (Apis mellifera L.) and squash bees (Peponapis pruinosa Say) were the predominant pollinators, and border treatments did not affect visitation. Hand pollination did not increase reproduction or yield, indicating that natural pollination was sufficient for full yield. This study confirms the effectiveness of perimeter trap crop systems and offers growers a more marketable trap crop for managing cucumber beetle damage. PMID:22182562
Zhang, Rui; Guo, Chunce; Zhang, Wengen; Wang, Peipei; Li, Lin; Duan, Xiaoshan; Du, Qinggao; Zhao, Liang; Shan, Hongyan; Hodges, Scott A; Kramer, Elena M; Ren, Yi; Kong, Hongzhi
Absence of petals, or being apetalous, is usually one of the most important features that characterizes a group of flowering plants at high taxonomic ranks (i.e., family and above). The apetalous condition, however, appears to be the result of parallel or convergent evolution with unknown genetic causes. Here we show that within the buttercup family (Ranunculaceae), apetalous genera in at least seven different lineages were all derived from petalous ancestors, indicative of parallel petal losses. We also show that independent petal losses within this family were strongly associated with decreased or eliminated expression of a single floral organ identity gene, APETALA3-3 (AP3-3), apparently owing to species-specific molecular lesions. In an apetalous mutant of Nigella, insertion of a transposable element into the second intron has led to silencing of the gene and transformation of petals into sepals. In several naturally occurring apetalous genera, such as Thalictrum, Beesia, and Enemion, the gene has either been lost altogether or disrupted by deletions in coding or regulatory regions. In Clematis, a large genus in which petalous species evolved secondarily from apetalous ones, the gene exhibits hallmarks of a pseudogene. These results suggest that, as a petal identity gene, AP3-3 has been silenced or down-regulated by different mechanisms in different evolutionary lineages. This also suggests that petal identity did not evolve many times independently across the Ranunculaceae but was lost in numerous instances. The genetic mechanisms underlying the independent petal losses, however, may be complex, with disruption of AP3-3 being either cause or effect. PMID:23479615
Ferrero, Victoria; Barrett, Spencer C H; Castro, Sílvia; Caldeirinha, Patrícia; Navarro, Luis; Loureiro, João; Rodríguez-Echeverría, Susana
Genetic diversity in populations of invasive species is influenced by a variety of factors including reproductive systems, ploidy level, stochastic forces associated with colonization and multiple introductions followed by admixture. Here, we compare genetic variation in native and introduced populations of the clonal plant Oxalis pes-caprae to investigate the influence of reproductive mode and ploidy on levels of diversity. This species is a tristylous geophyte native to South Africa. Invasive populations throughout much of the introduced range are composed of a sterile clonal pentaploid short-styled form. We examined morph ratios, ploidy level, reproductive mode and genetic diversity at nuclear microsatellite loci in 10 and 12 populations from South Africa and the Western Mediterranean region, respectively. Flow cytometry confirmed earlier reports of diploids and tetraploids in the native range, with a single population containing pentaploid individuals. Introduced populations were composed mainly of pentaploids, but sexual tetraploids were also found. There was clear genetic differentiation between ploidy levels, but sexual populations from both regions were not significantly different in levels of diversity. Invasive populations of the pentaploid exhibited dramatically reduced levels of diversity but were not genetically uniform. The occurrence of mixed ploidy levels and stylar polymorphism in the introduced range is consistent with multiple introductions to the Western Mediterranean. This inference was supported by variation patterns at microsatellite loci. Our study indicates that some invasive populations of Oxalis pes-caprae are not entirely clonal, as often assumed, and multiple introductions and recombination have the potential to increase genetic variation in the introduced range. PMID:25604701
Full Text Available E00407 Anemone altaica rhizome ... Rhizoma anemone Crude drug Anemone altaica, Anemone [TAX:22868] R ... anunculaceae (buttercup family) Anemone altaica rhizome ... (dried) Crude drugs [BR:br08305] Dicot plants: oth ... culaceae (buttercup family) E00407 Anemone altaica rhizome ...
Full Text Available TAX:49188] Ranunculaceae (buttercup family) Aconitum triphyllum tuberous root Crude drugs [BR:br08305] Dicot plants: others...E00577 Aconitum triphyllum tuberous root Crude drug Aconitum triphyllum, Aconitum [... Ranunculaceae (buttercup family) E00577 Aconitum triphyllum tuberous root ...
Full Text Available E00808 Black cohosh Black snakeroot Medicinal herb Actein, Cimicifugoside [CPD:C089...Medicinal herbs [BR:br08322] Dicot plants: others Ranunculaceae (buttercup family) E00808 Black cohosh ...
Full Text Available monin [CPD:C16913] Pulsatilla chinensis, Pulsatilla dahurica, Pulsatilla koreana [TAX:387930], Pulsatilla [T...931], Artemisia [TAX:4219], Gerbera piloselloides [TAX:496626], Saussurea radiata, Saussurea...e (buttercup family) Anemone, Asteraceae (daisy family) Inula cappa, Artemisia, Gerbera piloselloides, Saussurea...4], Potentilla chinensis [TAX:210858], Potentilla discolor [TAX:648872], Polycarpaea cor...ymbosa, Polycarpaea [TAX:431020] Ranunculaceae (buttercup family) Pulsatilla root Homonym: Ranunculacea
School Science Review, 1982
Presents procedures, exercises, demonstrations, and information on a variety of biology topics including labeling systems, biological indicators of stream pollution, growth of lichens, reproductive capacity of bulbous buttercups, a straw balance to measure transpiration, interaction of fungi, osmosis, and nitrogen fixation and crop production. (DC)
Full Text Available cup family) Aconitum coreanum tuberous root Crude drugs [BR:br08305] Dicot plants: others Ranunculaceae (buttercup family) E00580 Aconitum coreanum tuberous root ... ...E00580 Aconitum coreanum tuberous root Crude drug Aconitum coreanum [TAX:662772] Ranunculaceae (butter
Full Text Available cup family) Aconitum kusnesoffii, Aconitum tuberous root Crude drugs [BR:br08305] Dicot plants: others...E00576 Aconitum tuberous root Crude drug Aconitum kusnesoffii, Aconitum [TAX:49188] Ranunculaceae (butter... Ranunculaceae (buttercup family) E00576 Aconitum tuberous root ...
Tetrahedral hohlraums have been proposed as a means for achieving the highly uniform implosions needed for ignition with inertial confinement fusion (ICF) [J. D. Schnittman and R. S. Craxton, Phys. Plasmas 3, 3786 (1996)]. Recent experiments on the OMEGA laser system have achieved good drive uniformity consistent with theoretical predictions [J. M. Wallace et al., Phys. Rev. Lett. 82, 3807 (1999)]. To better understand these experiments and future investigations of high-convergence ICF implosions, the three-dimensional (3-D) view-factor code BUTTERCUP has been expanded to model the time-dependent radiation transport in the hohlraum and the hydrodynamic implosion of the capsule. Additionally, a 3-D postprocessor has been written to simulate x-ray images of the imploded core. Despite BUTTERCUP's relative simplicity, its predictions for radiation drive temperatures, fusion yields, and core deformation show close agreement with experiment. (c) 2000 American Institute of Physics
Akbulut, Sami; Semur, Heybet; Kose, Ozkan; Ozhasenekler, Ayhan; Celiktas, Mustafa; Basbug, Murat; Yagmur, Yusuf
Ranunculus arvensis (corn buttercup) is a plant species of the genus Ranunculus that is frequently used in the Far East to treat rheumatic diseases and several dermatological disorders. In Turkey, the plant is seen in the eastern and southeastern Anatolian highlands, which are underdeveloped areas of the country. Herein, we report three patients who used Ranunculus arvensis for the treatment of arthralgia and osteoarthritis. A distinctive phytodermatitis developed on the right thumb in one pa...
Adler, L S; Hazzard, R V
Perimeter trap cropping (PTC) is a method of integrated pest management (IPM) in which the main crop is surrounded with a perimeter trap crop that is more attractive to pests. Blue Hubbard (Cucurbita maxima Duch.) is a highly effective trap crop for butternut squash (C. moschata Duch. ex Poir) attacked by striped cucumber beetles (Acalymma vittatum Fabricius), but its limited marketability may reduce adoption of PTC by growers. Research comparing border crop varieties is necessary to provide options for growers. Furthermore, pollinators are critical for cucurbit yield, and the effect of PTC on pollination to main crops is unknown. We examined the effect of five border treatments on herbivory, pollination, and yield in butternut squash and manipulated herbivory and pollination to compare their importance for main crop yield. Blue Hubbard, buttercup squash (C. maxima Duch.), and zucchini (C. pepo L.) were equally attractive to cucumber beetles. Border treatments did not affect butternut leaf damage, but butternut flowers had the fewest beetles when surrounded by Blue Hubbard or buttercup squash. Yield was highest in the Blue Hubbard and buttercup treatments, but this effect was not statistically significant. Native bees accounted for 87% of pollinator visits, and pollination did not limit yield. There was no evidence that border crops competed with the main crop for pollinators. Our results suggest that both buttercup squash and zucchini may be viable alternatives to Blue Hubbard as borders for the main crop of butternut squash. Thus, growers may have multiple border options that reduce pesticide use, effectively manage pests, and do not disturb mutualist interactions with pollinators. PMID:19791616
Williams, Jonathan S.; Dungait, Jennifer A. J.; Bol, Roland; Abbott, Geoffrey D.
Background and aims Plant-derived phenols are a major input to the terrestrial carbon cycle that might be expected to contribute substantially to dissolved organic carbon (DOC) losses from soils. This study investigated changes in DOC and phenols in leachates from soil treated with individual plant litter types under seasonal temperature change. Methods Senescing grass, buttercup, ash and oak litters were applied to soil lysimeters. Leachates were collected over 22 months and analysed for DOC...
Full Text Available In this paper the authors consider bioecological peculiarities of some species of medicinal plants, containing cardiac glycosides and their distribution. The paper presents the tables, which contain data of the quantitative content of the amount of cardiac glycosides in the aerial and underground parts of some species of the Cruciferous, Buttercups, etc. in different ecological conditions. The article also introduces the specie of foxglove from the family of figwort, which defines the quantitative content of cardiac glycosides, as the leaves of these plants are a source of raw materials, producing cardiac glycosides.
Tusserkani, Ruzbeh; Poormohammadi, Hadi; Azadi, Azin
We present TripNet, a method for constructing phylogenetic networks from triplets. We will present the motivations behind our approach and its theoretical and empirical justification. To demonstrate the accuracy and efficiency of TripNet, we performed two simulations and also applied the method to five published data sets: Kreitman's data, a set of triplets from real yeast data obtained from the Fungal Biodiversity Center in Utrecht, a collection of 110 highly recombinant Salmonella multi-locus sequence typing sequences, and nrDNA ITS and cpDNA JSA sequence data of New Zealand alpine buttercups of Ranunculus sect. Pseudadonis. Finally, we compare our results with those already obtained by other authors using alternative methods. TripNet, data sets, and supplementary files are freely available for download at (www.bioinf.cs.ipm.ir/softwares/tripnet).
Nancy F. Glenn; Jessica J. Mitchell; Matthew O. Anderson; Ryan C. Hruska
UAV-based hyperspectral remote sensing capabilities developed by the Idaho National Lab and Idaho State University, Boise Center Aerospace Lab, were recently tested via demonstration flights that explored the influence of altitude on geometric error, image mosaicking, and dryland vegetation classification. The test flights successfully acquired usable flightline data capable of supporting classifiable composite images. Unsupervised classification results support vegetation management objectives that rely on mapping shrub cover and distribution patterns. Overall, supervised classifications performed poorly despite spectral separability in the image-derived endmember pixels. Future mapping efforts that leverage ground reference data, ultra-high spatial resolution photos and time series analysis should be able to effectively distinguish native grasses such as Sandberg bluegrass (Poa secunda), from invasives such as burr buttercup (Ranunculus testiculatus) and cheatgrass (Bromus tectorum).
Logan, David P.; Maher, Bridget J.; Dobson, Shirley S.; Connolly, Patrick G.
Fuller's rose weevil, Naupactus cervinus (Boheman) (Curculionidae: Entiminae), is an important quarantine pest of New Zealand kiwifruit exported to Asian markets. Both adults and larvae are considered to be polyphagous. In this study, the survival of larval N. cervinus was estimated on common groundcover species of kiwifruit (Actinidia spp.) in the Bay of Plenty, the main region in New Zealand where kiwifruit is grown. The botanical composition of groundcover in commercial kiwifruit orchards, characterised by survey, was dominated by ryegrass (Lolium perenne), with white clover (Trifolium repens), creeping buttercup (Ranunculus repens), wild strawberry (Duchesnea indica) and broadleaf dock (Rumex obtusifolius) in lower abundance. Survival to mature larvae or adult was relatively low (·11%) for N. cervinus introduced as neonates to field plots or potted ryegrass, white clover and broadleaf dock. White clover was a more favourable host for survival to adults than ryegrass. This study suggests that increased survival of N. cervinus larvae may occur where white clover and large dock plants are abundant, but that survival is likely to be highly variable because of the heterogeneous availability of preferred host plants and host plant quality. These data suggest that larval polyphagy is a strategy that enables N. cervinus to persist at low densities in kiwifruit orchards despite variation in the quality and diversity of groundcover. PMID:20298112
Palacio, Carlos; Masri, Ghania; Mooradian, Arshag D
Alternative medicine preparations represent a significant industry worldwide. Black cohosh (Cimicifuga racemosa), a buttercup plant grown in North America, is one such popular preparation for the treatment of menopausal symptoms. Because the proportion of women experiencing climacteric symptoms is high, black cohosh merits further study as to its efficacy and safety. Convincing evidence for its efficacy in this setting remains to be demonstrated. The purpose of this systematic review was to assess the current literature on the benefits of black cohosh for women experiencing climacteric symptoms. To this end, a PubMed search was conducted on 1 November 2007 using the search terms 'black cohosh' AND 'menopause'. The search was limited to randomized controlled trials in the English language involving adults. Several additional reviews dealing with alternative therapies for menopause were included to capture additional older and non-English language literature. Ultimately, 16 studies eligible for review were identified. Many of the studies had conflicting results. Methodological flaws included lack of uniformity of the drug preparation used, variable outcome measures and lack of a placebo group. The benefits of black cohosh in the management of climacteric symptoms remain to be proven. Case studies suggest an additional unexplored area of adverse events that also needs to be addressed. PMID:19102512
Ramadan, Mohamed Fawzy; Mohdaly, Adel Abdelrazek Abdelazim; Assiri, Adel M A; Tadros, Monier; Niemeyer, Bernd
New sustainable edible oil sources are desired to achieve supply chain flexibility and cost saving opportunities. Non-traditional fruit seeds are being considered because their constituents have unique chemical properties and may augment the supply of nutritional and functional products. Madhuca longifolia Syn. M. indica (Sapotaceae) is an important economic tree growing throughout the subtropical region of the Indo-Pak subcontinent. Information concerning the exact composition of mahua butter (known also as mowrah butter) from fruit-seeds of buttercup or Madhuca tree is scare. Few studies investigated mahua butter for its composition, nutritional value, biological activities and antioxidative properties. In consideration of potential utilization, detailed knowledge on the chemical composition, nutritional value and industrial applications of mahua butter is of major importance. The diversity of applications to which mahua butter can be put gives this substance great industrial importance. This review summarizes recent knowledge on bioactive compounds, functional properties as well as food and non-food industrial applications of mahua butter. Graphical abstractᅟ. PMID:27407181
Khan, Farhat Ali; Zahoor, Muhammad; Khan, Ezzat
Ranunculus muricatus is commonly known as spiny fruit buttercup and is used in the treatment of intermittent fevers, gout and asthma. Qualitative analysis of phytochemicals of Ranunculus muricatus indicated the presence of saponins, tannins, phenols, flavonoids and alkaloids. Saponins were present in high amount as compared with other chemicals. Inorganic and heavy metals constituents were determined. Heavy metals estimation in the sample showed that iron was present in high amount followed by zinc even then the concentration of these metals is below acceptable limit. The physical parameters, antioxidant and antimicrobial activities of the extracts were determined. Acetone extract fraction showed optimal antioxidant activity as compared to ethanol and chloroform fractions of the candidate plant. The antimicrobial and antifungal activities of the crude extract and extract fractions were determined by well agar diffusion method. Highest zone of inhibitions were observed for crude extract followed by acetone extract fraction against Micrococcus luteus. Antifungal activities were high for crude extracts against Candida Albican. Findings of this study show that Ranunculus muricatus has a good medicinal impact. PMID:27087095
Liliana M Cano
Full Text Available Pucciniamonoica is a spectacular plant parasitic rust fungus that triggers the formation of flower-like structures (pseudoflowers in its Brassicaceae host plant Boecherastricta. Pseudoflowers mimic in shape, color, nectar and scent co-occurring and unrelated flowers such as buttercups. They act to attract insects thereby aiding spore dispersal and sexual reproduction of the rust fungus. Although much ecological research has been performed on P. monoica-induced pseudoflowers, this system has yet to be investigated at the molecular or genomic level. To date, the molecular alterations underlying the development of pseudoflowers and the genes involved have not been described. To address this, we performed gene expression profiling to reveal 256 plant biological processes that are significantly altered in pseudoflowers. Among these biological processes, plant genes involved in cell fate specification, regulation of transcription, reproduction, floral organ development, anthocyanin (major floral pigments and terpenoid biosynthesis (major floral volatile compounds were down-regulated in pseudoflowers. In contrast, plant genes involved in shoot, cotyledon and leaf development, carbohydrate transport, wax biosynthesis, cutin transport and L-phenylalanine metabolism (pathway that results in phenylethanol and phenylacetaldehyde volatile production were up-regulated. These findings point to an extensive reprogramming of host genes by the rust pathogen to induce floral mimicry. We also highlight 31 differentially regulated plant genes that are enriched in the biological processes mentioned above, and are potentially involved in the formation of pseudoflowers. This work illustrates the complex perturbations induced by rust pathogens in their host plants, and provides a starting point for understanding the molecular mechanisms of pathogen-induced floral mimicry.
Tsao, Rong; Yang, Raymond
This study mainly focused on lutein content in several selected crops grown in southern Ontario, Canada. Marigold flower, a good rotation crop for the control of nematodes in tobacco fields was found to contain 0.77% lutein (after saponification, on dry basis). A high-speed counter-current chromatography (HSCCC) method using a two-phase solvent system consisting of hexane-ethanol-water (6:4.5:1.5, v/v/v) was developed for the purification of lutein from the saponification mixture of marigold flower extract. The purity of lutein prepared using this HSCCC method was 97%. Free lutein was found to be the predominant form in three squash varieties, and it was mostly found in the peel rather than the commonly consumed flesh. Sweet Mamma, Buttercup and Pepper squash varieties contained 25.4, 18.4 and 30.1mg/100g fresh weigh (FW) of lutein in the peels, respectively. These concentrations were significantly higher than that in spinach and kale (3.7 and 12.3 mg/100 g FW). beta-Carotene was found most in the peel of Sweet Mamma squash at 13.6 mg/100g FW, whereas it was below 2mg/100g FW in all other samples. Cooking increased extractable free lutein by 22-65% in squash peels. Lutein in Yukon Gold potato was at ca. 0.4 mg/100 g FW. Certain Yukon Gold was also found to contain violaxanthin (0.35 mg/100 g FW). Structures of lutein, beta-carotene and violaxanthin were identified by LC-atmospheric pressure chemical ionization MS in positive ion mode, and by comparing the retention time and UV-vis spectral data with standards. Results from this study suggest the selected crops and agri-food industrial processing by-products of these can be a good source of free lutein. PMID:16242702
Sarah E Edwards
Full Text Available Background:Equine dysautonomia or equine grass sickness (EGS, as it is more commonly known, is a usually fatal disease of equids of uncertain aetiology, although associated with grazing, that affects the autonomic and enteric nervous system. Lowered gastro-intestinal motility, leading to paralysis of the gut, is one of the main symptoms of EGS. Previous studies have implicated anaerobic bacteria, notably Clostridium botulinum, but what triggers the severe bacterial infestations remains enigmatic. We hypothesized that a detailed comparison of soil mineral and botanical composition of EGS and control sites would yield new insights into the causation of the disease. Results: Between March 2007 and September 2008, soil, plant, and water samples from a total of 23 EGS sites and 11 control sites were studied. Metal and non-metal element levels of the soil and herbage samples were assessed. Significantly, EGS sites had higher levels of soil nitrogen, and significantly higher levels of iron, lead, arsenic and chromium in the herbage. Toxic Ranunculus spp. (buttercups were found in abundance at every EGS site, making ingestion plausible. Conversely, neurotoxin-producing cyanobacteria were not found in any of the water samples analysed. Conclusions: The significantly higher levels of iron and heavy metals found in herbage growing in EGS sites, in addition to toxic Ranunculus species, suggest that previously unknown triggers are involved in a multi-factorial EGS aetiology. Our results also show that cyanobacteria on the other hand, are unlikely to be a factor in EGS. Consequently, the concomitant presence of two (or more factors could be the trigger for an outbreak of EGS and the combination of both seems to be a key predictor.
Bouchal, Johannes Martin; Grímsson, Friðgeir; Denk, Thomas
(basswood, mallow family), Myricaceae (bayberry), Oleaceae (olive family), Onagraceae (evening primrose family), Plumbaginaceae (sea-lavender), Polygonaceae (docks, knotweed), Ranunculaceae (buttercup family), Rosaceae (rose family), Salicaceae (willow), Sapindaceae (maple), Sapotaceae, and Ulmaceae (elm, Zelkova). The objectives of this investigation were (1) to evaluate whether the three palynological sections were deposited at the same time, and (2) to show regional vegetation differences within a single sedimentary basin. We found three general pollen zones corresponding to different sedimentary settings and palaeoenvironments. The first pollen zone was linked to lignite formation (swamp forest, fern spores, Alnus, Decodon). The second pollen zone reflects lacustrine conditions (Typhaceae) and surrounding hinterland vegetation dominated by Fagaceae. The third pollen zone is dominated by herbaceous taxa, whereas woody taxa are less diverse and less abundant. In general, the three palynological sections are congruent in reflecting distinct pollen zones. However main vegetation types may be represented by different dominating taxa (e. g. Alnus dominace in Eskihisar and Tı naz localities while absent in Salihpaşalar) and rare taxa may differ between localities. Our results demonstrate that in order to achieve a comprehensive understanding of environmental and vegetation conditions in a sedimentary basin, a single palynological section (locality) may not capture the entirety of environmental conditions and changes.
Ashworth, A. C.; Lewis, A.; Marchant, D. R.
The discovery of several locations in the Transantarctic Mountains that contain macrofossils and pollen is transforming our understanding of late Cenozoic Antarctica. The most southerly location is on the Beardmore Glacier (85.1°S) about 500 km from the South Pole. The environment was an active glacial margin in which plants, insects and freshwater mollusks inhabited the sand and gravel bars and small lakes on an outwash plain. In addition to leaves and wood of dwarf Nothofagus (Southern Beech) shrubs, achenes of Ranunculus (Buttercup), in situ cushion growth forms of mosses and a vascular plant, the assemblages contains various exoskeletal parts of carabid and curculionid beetles and a cyclorrhaphan fly, the shells of freshwater bivalve and gastropod species and a fish tooth. Initially the deposits were assigned a Pliocene age (3.5 Ma) but a mid- to early Miocene age is more probable (c. 14 - 25 Ma) based on correlation of fossil pollen from the deposits with 39Ar/40Ar dated pollen assemblages from the McMurdo Dry Valleys locations. The oldest location within the Dry Valleys also involved an active ice margin but was part of a valley system that was completely deglaciated for intervals long enough for thick paleosols to develop. The Friis Hills fossil deposits of the Taylor Valley region (77.8°S) are at least 19.76 Ma based on the 39Ar/40Ar age of a volcanic ash bed. The valley floor during the non-glacial phases had poorly-drained soils and the extensive development of mossy mires. Wood and leaves of Nothofagus are abundant in lacustrine deposits. The silts of shallow fluvial channels contain abundant megaspores and spiky leaves of the aquatic lycopod Isoetes (Quillwort). Fossils of beetles are also present in these deposits. During the glacial phases, proglacial lakes were surrounded by dwarfed, deciduous Nothofagus shrubs. The youngest fossils recovered from the Dry Valleys are from the Olympus Range (77.5°S) with an age of 14.07 Ma. The environment was an
Ashworth, A. C.; Lewis, A. R.
Fossils from Antarctic Miocene terrestrial deposits, coupled with stratigraphic, geochemical and paleontological data from marine boreholes, provide new insights into the climatic history of the continent. During the Miocene, ice caps coalesced to form ice sheets and vegetated surfaces gave way to barren expanses. The cryospheric changes especially have global climatic implications. The fossil data consists of diatoms, pollen and spores, and macroscopic remains of plants, ostracods, insects, molluscs and a fish. Plant fossils include wood and leaves of Nothofagus (southern beech), seeds of several vascular plants, including Ranunculus (buttercup), Hippuris (mare's-tail) and Myriophyllum (watermilfoil), megaspores of Isoetes (quillwort), and moss species. The insect chitin consists of larval head capsules of Chironomidae (midges) and exoskeletal parts of Coleoptera (beetles). The molluscs include freshwater gastropods and bivalves. The majority of these taxa are likely descendants of taxa that had survived on the continent from the Paleogene or earlier. Even though early Miocene glaciations may have been large, the climate was never cold enough to cause the extinction of the biota, which probably survived in coastal refugia. Early Miocene (c. 20 Ma) macrofossils from the McMurdo Dry Valleys (77°S) support palynological interpretations from the Cape Roberts and ANDRILL marine records that the upland vegetation was a shrub tundra. Mean summer temperature (MST) in the uplands was c. 6°C and possibly higher at the coast. The climate was wet, supporting mires and lakes. By the mid-Miocene, even though the climate continued to be wet. MST was c. 4°C which was too cold to support Nothofagus and most vascular plant species. Stratigraphic evidence indicates that the time between the Early and Mid-Miocene was a time of repeated ice advances and retreats of small glaciers originating from ice caps. At c. 14 Ma there appears to have been a modal shift in climate to