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Sample records for anomodonts tetrapoda therapsida

  1. Global taxonomic diversity of anomodonts (tetrapoda, therapsida) and the terrestrial rock record across the Permian-Triassic boundary.

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    Fröbisch, Jörg

    2008-01-01

    The end-Permian biotic crisis (~252.5 Ma) represents the most severe extinction event in Earth's history. This paper investigates diversity patterns in Anomodontia, an extinct group of therapsid synapsids ('mammal-like reptiles'), through time and in particular across this event. As herbivores and the dominant terrestrial tetrapods of their time, anomodonts play a central role in assessing the impact of the end-Permian extinction on terrestrial ecosystems. Taxonomic diversity analysis reveals that anomodonts experienced three distinct phases of diversification interrupted by the same number of extinctions, i.e. an end-Guadalupian, an end-Permian, and a mid-Triassic extinction. A positive correlation between the number of taxa and the number of formations per time interval shows that anomodont diversity is biased by the Permian-Triassic terrestrial rock record. Normalized diversity curves indicate that anomodont richness continuously declines from the Middle Permian to the Late Triassic, but also reveals all three extinction events. Taxonomic rates (origination and extinction) indicate that the end-Guadalupian and end-Permian extinctions were driven by increased rates of extinction as well as low origination rates. However, this pattern is not evident at the final decline of anomodont diversity during the Middle Triassic. Therefore, it remains unclear whether the Middle Triassic extinction represents a gradual or abrupt event that is unique to anomodonts or more common among terrestrial tetrapods. The end-Permian extinction represents the most distinct event in terms of decline in anomodont richness and turnover rates.

  2. Global taxonomic diversity of anomodonts (tetrapoda, therapsida and the terrestrial rock record across the Permian-Triassic boundary.

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    Jörg Fröbisch

    Full Text Available The end-Permian biotic crisis (~252.5 Ma represents the most severe extinction event in Earth's history. This paper investigates diversity patterns in Anomodontia, an extinct group of therapsid synapsids ('mammal-like reptiles', through time and in particular across this event. As herbivores and the dominant terrestrial tetrapods of their time, anomodonts play a central role in assessing the impact of the end-Permian extinction on terrestrial ecosystems. Taxonomic diversity analysis reveals that anomodonts experienced three distinct phases of diversification interrupted by the same number of extinctions, i.e. an end-Guadalupian, an end-Permian, and a mid-Triassic extinction. A positive correlation between the number of taxa and the number of formations per time interval shows that anomodont diversity is biased by the Permian-Triassic terrestrial rock record. Normalized diversity curves indicate that anomodont richness continuously declines from the Middle Permian to the Late Triassic, but also reveals all three extinction events. Taxonomic rates (origination and extinction indicate that the end-Guadalupian and end-Permian extinctions were driven by increased rates of extinction as well as low origination rates. However, this pattern is not evident at the final decline of anomodont diversity during the Middle Triassic. Therefore, it remains unclear whether the Middle Triassic extinction represents a gradual or abrupt event that is unique to anomodonts or more common among terrestrial tetrapods. The end-Permian extinction represents the most distinct event in terms of decline in anomodont richness and turnover rates.

  3. Global Taxonomic Diversity of Anomodonts (Tetrapoda, Therapsida) and the Terrestrial Rock Record Across the Permian-Triassic Boundary

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    Jörg Fröbisch

    2008-01-01

    The end-Permian biotic crisis (~252.5 Ma) represents the most severe extinction event in Earth's history. This paper investigates diversity patterns in Anomodontia, an extinct group of therapsid synapsids ('mammal-like reptiles'), through time and in particular across this event. As herbivores and the dominant terrestrial tetrapods of their time, anomodonts play a central role in assessing the impact of the end-Permian extinction on terrestrial ecosystems. Taxonomic diversity analysis reveals...

  4. Decoupling of morphological disparity and taxic diversity during the adaptive radiation of anomodont therapsids.

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    Ruta, Marcello; Angielczyk, Kenneth D; Fröbisch, Jörg; Benton, Michael J

    2013-10-07

    Adaptive radiations are central to macroevolutionary theory. Whether triggered by acquisition of new traits or ecological opportunities arising from mass extinctions, it is debated whether adaptive radiations are marked by initial expansion of taxic diversity or of morphological disparity (the range of anatomical form). If a group rediversifies following a mass extinction, it is said to have passed through a macroevolutionary bottleneck, and the loss of taxic or phylogenetic diversity may limit the amount of morphological novelty that it can subsequently generate. Anomodont therapsids, a diverse clade of Permian and Triassic herbivorous tetrapods, passed through a bottleneck during the end-Permian mass extinction. Their taxic diversity increased during the Permian, declined significantly at the Permo-Triassic boundary and rebounded during the Middle Triassic before the clade's final extinction at the end of the Triassic. By sharp contrast, disparity declined steadily during most of anomodont history. Our results highlight three main aspects of adaptive radiations: (i) diversity and disparity are generally decoupled; (ii) models of radiations following mass extinctions may differ from those triggered by other causes (e.g. trait acquisition); and (iii) the bottleneck caused by a mass extinction means that a clade can emerge lacking its original potential for generating morphological variety.

  5. First record of Cephalobaena tetrapoda (Pentastomida: Cephalobaenidae) as a parasite on Liophis lineatus (Ophidia: Colubridae) in Northeast Brazil.

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    Almeida, W O; Brito, S V; Ferreira, F S; Christoffersen, M L

    2006-05-01

    Cephalobaenidae constitutes one of the main pentastomid groups infecting the respiratory tract of snakes. Six specimens of Liophis lineatus, a colubrid, were collected by active capture and pitfalls installed on the banks of the Batateiras river, close to its source, in the APA - Area de Proteção Ambiental (a protected environmental area of the IBAMA - Brazilian Institute for the Environment and Natural Resources), and in a remnant of the humid tropical forest FLONA - Floresta Nacional do Araripe, both in the municipality of Crato, state of Ceará, Northeast Brazil. Out of the six specimens of L. lineatus examined, only one had its lung infected by the pentastomid Cephalobaena tetrapoda. This represents the first record of C. tetrapoda as a parasite of a snake in Northeast Brazil, as well as the first record of a colubrid, L. lineatus, as a new host for the pentastomid in Brazil.

  6. Lectin histochemistry shows the comparative biosynthesis and cellular biodistribution of alpha L-fucose residues in some tissues of tetrapoda representatives.

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    Awaad, Aziz

    2016-01-01

    Fucose is a monosaccharide that plays several immunological roles. This study investigated the comparative biosynthesis and cellular biodistribution of fucose residues in some tissues of tetrapoda representatives using lectin histochemistry. In this study, the mouse was used as a representative for mammalian, pigeon for avian, lizard for reptilian, and toad for amphibians. The localization of the fucose residues was seen in several cell types of mice ileum, such as villi microfold (M) cells, goblet cells, some of intestinal crypts cells, and lamina propria cells. In other tetrapoda representatives, fucose was only seen in M cells of lizard ileum and some cells of villi lamina propria of pigeon, lizard, and toad. It was also observed in the pancreatic acinar cells of the mouse and some cell aggregations of pancreatic parenchyma of the lizard. Contrarily, it was not seen either in pigeon or in toad pancreases parenchyma. Spleen of all animals showed the fucose residues in some splenic cells in the red pulp only, barring the white pulp. The liver parenchyma of all tetrapoda representatives hadn't fucose residues. The fucose cellular biodistribution in some cells of tetrapoda representatives differed based on the cell type. In the mouse, it was highly seen in the apical cytoplasm of the villi M cells as well as in the cup-like part of goblet cells. In addition, it was seen as "rings" in the granule membranes of the Ulex europeaus agglutinin I (UEAI(+)) cells in the intestinal crypts cells. Furthermore, the UEAI(+) cells in the lamina propria showed fucose granules in their cytoplasm. There is no clear evidence about the relation between the cellular biosynthesis of fucose residues and mucosal immune cells. The role of fucose residues in the pancreatic acinar cells are not well understood and need further investigations. In this study, fucose residues were synthesized in several types of cells in the mouse ileum, spleen and pancreas as compared with other tetrapoda. The

  7. Growth increments in teeth of Diictodon (Therapsida

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    J. Francis Thackeray

    1991-09-01

    Full Text Available Growth increments circa 0.02 mm in width have been observed in sectioned tusks of Diictodon from the Late Permian lower Beaufort succession of the South African Karoo, dated between about 260 and 245 million years ago. Mean growth increments show a decline from relatively high values in the Tropidostoma/Endothiodon Assemblage Zone, to lower values in the Aulacephalodon/Cistecephaluszone, declining still further in the Dicynodon lacerficeps/Whaitsia zone at the end of the Permian. These changes coincide with gradual changes in carbon isotope ratios measured from Diictodon tooth apatite. It is suggested that the decline in growth increments is related to environmental changes associated with a decline in primary production which contributed to the decline in abundance and ultimate extinction of Diictodon.

  8. The brain of two mammal-like reptiles (Cynodontia - Therapsida).

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    Quiroga, J C

    1979-01-01

    The endocasts of the cynodonts Massetognathus sp. and cf. Probelesodon are studied from descriptive and quantitative viewpoints. The morphology of the casts is described briefly, doing special attention to those features that import to the quantitative analysis, as for instance the general appearance of the casts and some vascular impressions. The general conclusions of this study are: 1.--Massetognathus sp. has had a brain with rather long olfactory peduncles and perhaps not greatly developed olfactory bulbs which could imply a non-macroosmatic condition, up to date not known for cynodonts. Cf. Probelesodon, on the other hand, shows a brain type similar to those of other cynodonts. 2.--Certain cynodonts at least, have had brains that filled fairly well the endocranial cavity. 3.--The cynodonts Massentognathus sp. and cf. Probelesodon, as surely other species, have acquired in Middle Triassic times a relative brain size rather closed to that of certain fossil and living mammals.

  9. The anatomy of the bifurcated neural spine and its occurrence within Tetrapoda.

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    Woodruff, D Cary

    2014-09-01

    Vertebral neural spine bifurcation has been historically treated as largely restrictive to sauropodomorph dinosaurs; wherein it is inferred to be an adaptation in response to the increasing weight from the horizontally extended cervical column. Because no extant terrestrial vertebrates have massive, horizontally extended necks, extant forms with large cranial masses were examined for the presence of neural spine bifurcation. Here, I report for the first time on the soft tissue surrounding neural spine bifurcation in a terrestrial quadruped through the dissection of three Ankole-Watusi cattle. With horns weighing up to a combined 90 kg, the Ankole-Watusi is unlike any other breed of cattle in terms of cranial weight and presence of neural spine bifurcation. Using the Ankole-Watusi as a model, it appears that neural spine bifurcation plays a critical role in supporting a large mobile weight adjacent to the girdles. In addition to neural spine bifurcation being recognized within nonavian dinosaurs, this vertebral feature is also documented within many members of temnospondyls, captorhinids, seymouriamorphs, diadectomorphs, Aves, marsupials, artiodactyls, perissodactyls, and Primates, amongst others. This phylogenetic distribution indicates that spine bifurcation is more common than previously thought, and that this vertebral adaptation has contributed throughout the evolutionary history of tetrapods. Neural spine bifurcation should now be recognized as an anatomical component adapted by some vertebrates to deal with massive, horizontal, mobile weights adjacent the girdles.

  10. Skeletal Morphogenesis of Microbrachis and Hyloplesion (Tetrapoda: Lepospondyli, and Implications for the Developmental Patterns of Extinct, Early Tetrapods.

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    Jennifer C Olori

    Full Text Available The ontogeny of extant amphibians often is used as a model for that of extinct early tetrapods, despite evidence for a spectrum of developmental modes in temnospondyls and a paucity of ontogenetic data for lepospondyls. I describe the skeletal morphogenesis of the extinct lepospondyls Microbrachis pelikani and Hyloplesion longicostatum using the largest samples examined for either taxon. Nearly all known specimens were re-examined, allowing for substantial anatomical revisions that affect the scoring of characters commonly used in phylogenetic analyses of early tetrapods. The palate of H. longicostatum is re-interpreted and suggested to be more similar to that of M. pelikani, especially in the nature of the contact between the pterygoids. Both taxa possess lateral lines, and M. pelikani additionally exhibits branchial plates. However, early and rapid ossification of the postcranial skeleton, including a well-developed pubis and ossified epipodials, suggests that neither taxon metamorphosed nor were they neotenic in the sense of branchiosaurids and salamanders. Morphogenetic patterns in the foot suggest that digit 5 was developmentally delayed and the final digit to ossify in M. pelikani and H. longicostatum. Overall patterns of postcranial ossification may indicate postaxial dominance in limb and digit formation, but also more developmental variation in early tetrapods than has been appreciated. The phylogenetic position and developmental patterns of M. pelikani and H. longicostatum are congruent with the hypothesis that early tetrapods lacked metamorphosis ancestrally and that stem-amniotes exhibited derived features of development, such as rapid and complete ossification of the skeleton, potentially prior to the evolution of the amniotic egg.

  11. Origin of secretin receptor precedes the advent of tetrapoda: evidence on the separated origins of secretin and orexin.

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    Janice K V Tam

    Full Text Available At present, secretin and its receptor have only been identified in mammals, and the origin of this ligand-receptor pair in early vertebrates is unclear. In addition, the elusive similarities of secretin and orexin in terms of both structures and functions suggest a common ancestral origin early in the vertebrate lineage. In this article, with the cloning and functional characterization of secretin receptors from lungfish and X. laevis as well as frog (X. laevis and Rana rugulosa secretins, we provide evidence that the secretin ligand-receptor pair has already diverged and become highly specific by the emergence of tetrapods. The secretin receptor-like sequence cloned from lungfish indicates that the secretin receptor was descended from a VPAC-like receptor prior the advent of sarcopterygians. To clarify the controversial relationship of secretin and orexin, orexin type-2 receptor was cloned from X. laevis. We demonstrated that, in frog, secretin and orexin could activate their mutual receptors, indicating their coordinated complementary role in mediating physiological processes in non-mammalian vertebrates. However, among the peptides in the secretin/glucagon superfamily, secretin was found to be the only peptide that could activate the orexin receptor. We therefore hypothesize that secretin and orexin are of different ancestral origins early in the vertebrate lineage.

  12. A new prozostrodontian cynodont (Therapsida from the Late Triassic Riograndia Assemblage Zone (Santa Maria Supersequence of Southern Brazil

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    MARINA B. SOARES

    2014-12-01

    Full Text Available We report here on a new prozostrodontian cynodont, Botucaraitherium belarminoi gen. et sp. nov., from the Late Triassic Riograndia Assemblage Zone (AZ of the Candelária Sequence (Santa Maria Supersequence, collected in the Botucaraí Hill Site, Candelária Municipality, state of Rio Grande do Sul, Brazil. The new taxon is based on a single specimen (holotype MMACR-PV-003-T which includes the left lower jaw, without postdentary bones, bearing the root of the last incisor, canine and four postcanines plus one partial crown inside the dentary, not erupted, and two maxillary fragments, one with a broken canine and another with one postcanine. The features of the lower jaw and lower/upper postcanines resemble those of the prozostrodontians Prozostrodon brasiliensis from the older Hyperodapedon AZ and Brasilodon quadrangularis and Brasilitherium riograndensis from the same Riograndia AZ. The inclusion of Botucaraitherium within a broad phylogenetic analysis, positioned it as a more derived taxon than tritylodontids, being the sister-taxon of Brasilodon, Brasilitherium plus Mammaliaformes. Although the new taxon is based on few cranial elements, it represents a additional faunal component of the Triassic Riograndia AZ of southern Brazil, in which small-sized derived non-mammaliaform cynodonts, closely related to the origin of mammaliaforms, were ecologically well succeed and taxonomically diverse.

  13. Bone microstructure and the evolution of growth patterns in Permo-Triassic therocephalians (Amniota, Therapsida of South Africa

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    Adam K. Huttenlocker

    2014-04-01

    Full Text Available Therocephalians were a speciose clade of nonmammalian therapsids whose ecological diversity and survivorship of the end-Permian mass extinction offer the potential to investigate the evolution of growth patterns across the clade and their underlying influences on post-extinction body size reductions, or ‘Lilliput effects’. We present a phylogenetic survey of limb bone histology and growth patterns in therocephalians from the Middle Permian through Middle Triassic of the Karoo Basin, South Africa. Histologic sections were prepared from 80 limb bones representing 11 genera of therocephalians. Histologic indicators of skeletal growth, including cortical vascularity (%CV and mean primary osteon diameters (POD, were evaluated in a phylogenetic framework and assessed for correlations with other biologically significant variables (e.g., size and robusticity. Changes in %CV and POD correlated strongly with evolutionary changes in body size (i.e., smaller-bodied descendants tended to have lower %CV than their larger-bodied ancestors across the tree. Bone wall thickness tended to be high in early therocephalians and lower in the gracile-limbed baurioids, but showed no general correlation with cross-sectional area or degree of vascularity (and, thus, growth. Clade-level patterns, however, deviated from previously studied within-lineage patterns. For example, Moschorhinus, one of few therapsid genera to have survived the extinction boundary, demonstrated higher %CV in the Triassic than in the Permian despite its smaller size in the extinction aftermath. Results support a synergistic model of size reductions for Triassic therocephalians, influenced both by within-lineage heterochronic shifts in survivor taxa (as reported in Moschorhinus and the dicynodont Lystrosaurus and phylogenetically inferred survival of small-bodied taxa that had evolved short growth durations (e.g., baurioids. These findings mirror the multi-causal Lilliput patterns described in marine faunas, but contrast with skeletochronologic studies that suggest slow, prolonged shell secretion over several years in marine benthos. Applications of phylogenetic comparative methods to new histologic data will continue to improve our understanding of the evolutionary dynamics of growth and body size shifts during mass extinctions and recoveries.

  14. Bone microstructure and the evolution of growth patterns in Permo-Triassic therocephalians (Amniota, Therapsida) of South Africa.

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    Huttenlocker, Adam K; Botha-Brink, Jennifer

    2014-01-01

    Therocephalians were a speciose clade of nonmammalian therapsids whose ecological diversity and survivorship of the end-Permian mass extinction offer the potential to investigate the evolution of growth patterns across the clade and their underlying influences on post-extinction body size reductions, or 'Lilliput effects'. We present a phylogenetic survey of limb bone histology and growth patterns in therocephalians from the Middle Permian through Middle Triassic of the Karoo Basin, South Africa. Histologic sections were prepared from 80 limb bones representing 11 genera of therocephalians. Histologic indicators of skeletal growth, including cortical vascularity (%CV) and mean primary osteon diameters (POD), were evaluated in a phylogenetic framework and assessed for correlations with other biologically significant variables (e.g., size and robusticity). Changes in %CV and POD correlated strongly with evolutionary changes in body size (i.e., smaller-bodied descendants tended to have lower %CV than their larger-bodied ancestors across the tree). Bone wall thickness tended to be high in early therocephalians and lower in the gracile-limbed baurioids, but showed no general correlation with cross-sectional area or degree of vascularity (and, thus, growth). Clade-level patterns, however, deviated from previously studied within-lineage patterns. For example, Moschorhinus, one of few therapsid genera to have survived the extinction boundary, demonstrated higher %CV in the Triassic than in the Permian despite its smaller size in the extinction aftermath. Results support a synergistic model of size reductions for Triassic therocephalians, influenced both by within-lineage heterochronic shifts in survivor taxa (as reported in Moschorhinus and the dicynodont Lystrosaurus) and phylogenetically inferred survival of small-bodied taxa that had evolved short growth durations (e.g., baurioids). These findings mirror the multi-causal Lilliput patterns described in marine faunas, but contrast with skeletochronologic studies that suggest slow, prolonged shell secretion over several years in marine benthos. Applications of phylogenetic comparative methods to new histologic data will continue to improve our understanding of the evolutionary dynamics of growth and body size shifts during mass extinctions and recoveries.

  15. Two New Cynodonts (Therapsida) from the Middle-Early Late Triassic of Brazil and Comments on South American Probainognathians

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    Soares, Marina Bento; Schwanke, Cibele

    2016-01-01

    We describe two new cynodonts from the early Late Triassic of southern Brazil. One taxon, Bonacynodon schultzi gen. et sp. nov., comes from the lower Carnian Dinodontosaurus AZ, being correlated with the faunal association at the upper half of the lower member of the Chañares Formation (Ischigualasto-Villa Unión Basin, Argentina). Phylogenetically, Bonacynodon is a closer relative to Probainognathus jenseni than to any other probainognathian, bearing conspicuous canines with a denticulate distal margin. The other new taxon is Santacruzgnathus abdalai gen. et sp. nov. from the Carnian Santacruzodon AZ. Although based exclusively on a partial lower jaw, it represents a probainognathian close to Prozostrodon from the Hyperodapedon AZ and to Brasilodon, Brasilitherium and Botucaraitherium from the Riograndia AZ. The two new cynodonts and the phylogenetic hypothesis presented herein indicate the degree to which our knowledge on probainognathian cynodonts is incomplete and also the relevance of the South American fossil record for understanding their evolutionary significance. The taxonomic diversity and abundance of probainognathians from Brazil and Argentina will form the basis of deep and complex studies to address the evolutionary transformations of cynodonts leading to mammals. PMID:27706191

  16. Nasal anatomy of the non-mammaliaform cynodont Brasilitherium riograndensis (Eucynodontia, Therapsida) reveals new insight into mammalian evolution.

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    Ruf, Irina; Maier, Wolfgang; Rodrigues, Pablo G; Schultz, Cesar L

    2014-11-01

    The mammalian nasal cavity is characterized by a unique anatomy with complex internal features. The evolution of turbinals was correlated with endothermic and macrosmatic adaptations in therapsids and in early mammals, which is still apparent in their twofold function (warming and moistening of air, olfaction). Fossil evidence for the transformation from the nonmammalian to the mammalian nasal cavity pattern has been poor and inadequate. Ossification of the cartilaginous nasal capsule and turbinals seems to be a feature that occurred only very late in synapsid evolution but delicate ethmoidal bones are rarely preserved. Here we provide the first µCT investigation of the nasal cavity of the advanced non-mammaliaform cynodont Brasilitherium riograndensis from the Late Triassic of Southern Brazil, a member of the sister-group of mammaliaforms, in order to elucidate a critical anatomical transition in early mammalian evolution. Brasilitherium riograndensis already had at least partially ossified turbinals as remnants of the nasoturbinal and the first ethmoturbinal are preserved. The posterior nasal septum is partly ossified and contributes to a mesethmoid. The nasal cavity is posteriorly expanded and forms a distinctive pars posterior (ethmoidal recess) that is ventrally separated from the nasopharyngeal duct by a distinct lamina terminalis. Thus, our observations clearly demonstrate that principal features of the mammalian nasal cavity were already present in the sister-group of mammaliaforms.

  17. Two New Cynodonts (Therapsida) from the Middle-Early Late Triassic of Brazil and Comments on South American Probainognathians.

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    Martinelli, Agustín G; Soares, Marina Bento; Schwanke, Cibele

    2016-01-01

    We describe two new cynodonts from the early Late Triassic of southern Brazil. One taxon, Bonacynodon schultzi gen. et sp. nov., comes from the lower Carnian Dinodontosaurus AZ, being correlated with the faunal association at the upper half of the lower member of the Chañares Formation (Ischigualasto-Villa Unión Basin, Argentina). Phylogenetically, Bonacynodon is a closer relative to Probainognathus jenseni than to any other probainognathian, bearing conspicuous canines with a denticulate distal margin. The other new taxon is Santacruzgnathus abdalai gen. et sp. nov. from the Carnian Santacruzodon AZ. Although based exclusively on a partial lower jaw, it represents a probainognathian close to Prozostrodon from the Hyperodapedon AZ and to Brasilodon, Brasilitherium and Botucaraitherium from the Riograndia AZ. The two new cynodonts and the phylogenetic hypothesis presented herein indicate the degree to which our knowledge on probainognathian cynodonts is incomplete and also the relevance of the South American fossil record for understanding their evolutionary significance. The taxonomic diversity and abundance of probainognathians from Brazil and Argentina will form the basis of deep and complex studies to address the evolutionary transformations of cynodonts leading to mammals.

  18. Phylogeny mandalas for illustrating the Tree of Life.

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    Hasegawa, Masami

    2016-11-02

    A circular phylogeny with photos or drawings of species is named a phylogeny mandala. This is one of the ways for illustrating the Tree of Life, and is suitable to show visually how the biodiversity has developed in the course of evolution as clarified by the molecular phylogenetics. To demonstrate the recent progress of molecular phylogenetics, six phylogeny mandalas for various taxonomic groups of life were presented; i.e., (1) Eukaryota, (2) Metazoa, (3) Hexapoda, (4) Tetrapoda, (5) Eutheria, and (6) Primates.

  19. The lineage-specific evolution of aquaporin gene clusters facilitated tetrapod terrestrial adaptation.

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    Roderick Nigel Finn

    Full Text Available A major physiological barrier for aquatic organisms adapting to terrestrial life is dessication in the aerial environment. This barrier was nevertheless overcome by the Devonian ancestors of extant Tetrapoda, but the origin of specific molecular mechanisms that solved this water problem remains largely unknown. Here we show that an ancient aquaporin gene cluster evolved specifically in the sarcopterygian lineage, and subsequently diverged into paralogous forms of AQP2, -5, or -6 to mediate water conservation in extant Tetrapoda. To determine the origin of these apomorphic genomic traits, we combined aquaporin sequencing from jawless and jawed vertebrates with broad taxon assembly of >2,000 transcripts amongst 131 deuterostome genomes and developed a model based upon Bayesian inference that traces their convergent roots to stem subfamilies in basal Metazoa and Prokaryota. This approach uncovered an unexpected diversity of aquaporins in every lineage investigated, and revealed that the vertebrate superfamily consists of 17 classes of aquaporins (Aqp0 - Aqp16. The oldest orthologs associated with water conservation in modern Tetrapoda are traced to a cluster of three aqp2-like genes in Actinistia that likely arose >500 Ma through duplication of an aqp0-like gene present in a jawless ancestor. In sea lamprey, we show that aqp0 first arose in a protocluster comprised of a novel aqp14 paralog and a fused aqp01 gene. To corroborate these findings, we conducted phylogenetic analyses of five syntenic nuclear receptor subfamilies, which, together with observations of extensive genome rearrangements, support the coincident loss of ancestral aqp2-like orthologs in Actinopterygii. We thus conclude that the divergence of sarcopterygian-specific aquaporin gene clusters was permissive for the evolution of water conservation mechanisms that facilitated tetrapod terrestrial adaptation.

  20. Pentastomídeos de répteis do Brasil: revisão dos cephalobaenidae

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    A. Arandas Rêgo

    1983-12-01

    Full Text Available Foram estudados os Cephalobaenidae (Pentastomida, depositados na coleção helmintológica do Instituto Oswaldo Cruz e na coleção de parasitologia do Instituto Butantan. São redescritas e discutidas as espécies, Cephalobaena tetrapoda, C. freitasi, C. giglioli, Raillietiella furcocerca e Mahafaliella venteli. Esses parasitas foram coletados dos répteis: Lachesis sp., Drymarchon c. corais, Xenodon merremii, Crotatus terrificus, Amphisbaena sp., Tropidurus torquatus, Bothrops atrox, Mabuya punctata e de Bufo paracnemis (anfíbio.In this work the author studies Cephalobaenidae parasites using specimens from the helminthological collection of the Oswaldo Cruz and Butantan Institutes. This material was collected from Lachesis sp., Drymarchon corais, Xenodon merremii, Crotalus terrificus, Amphisbaena sp., Tropidurus torquatus, Bothrops atrox, Mabuya punctata (Reptilia and Bufo paracnemis (Amphibia. The species studied are Cephalobaena tetrapoda Heymons, 1922, Cephalobaena giglioli (Hett, 1924 comb. n., Cephalobaena freitasi (Motta & Gomes, 1968 comb. n., Raillietiella furcocerca (Diesing, 1836 and Mahafaliella venteli (Motta, 1965. C. recurvocauda becomes a synonym of C. tetrapoda and as do the specimens that Motta called erronously R. furcocerca. Raillietiella giglioli is changed to Cephalobaena giglioli (Hett, 1924 comb. n. The author describes here the male of C. giglioli for the first time. Travassostulida freitasi and T. acutiacanthus enter in synonymy with C. freitasi, and T. acutiacanthus is considered to be a subspecies of C. freitasi. Raillietiella gomesi becomes a synonym of R. furcocerca. The author discusses Mahafaliella venteli, and also questions the validity of the genus Gretillaria proposed by Motta for some species of Raillietiella. The latter is considered a synonym of Raillietiella.

  1. Prevalence and intensity of pentastomid infection in two species of snakes from northeastern Brazil

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    WO Almeida

    Full Text Available This study aimed to evaluate the infection rates of snakes by pentastomids in the semi-arid region of Brazil. Fifteen snakes (four Micrurus ibiboboca (Merrem, 1820 and eleven Philodryas nattereri Steindachner, 1870 were collected between January and April of 2005, in the municipality of Crato (07° 14' S and 39° 24' W, State of Ceará, Brazil. Laboratorial analysis of the respiratory tracts of the sampled snakes indicated differences in host infection rates: four individuals of P. nattereri (36.4% were infected by Cephalobaena tetrapoda Heymons, 1922 (mean infection intensity 1.5 ± 0.28, 1-2 and three specimens (27.3% by Raillietiella furcocerca (Diesing, 1863 (2.3 ± 1.32, 1-5. Only one individual of M. ibiboboca (25% was infected by a non-identified species of Raillietiella sp. These are the first data on pentastomid infection in snakes in Northeastern Brazil and both snake species comprise new host records for the pentastomids. The results also indicate that the generalist parasites C. tetrapoda and R. furcocerca share their definitive hosts.

  2. Pentastomid infection in Philodryas nattereri Steindachner, 1870 and Oxybelis aeneus (Wagler, 1824) (Squamata: Colubridae) in a caatinga of northeastern Brazil.

    Science.gov (United States)

    Almeida, W O; Guedes, T B; Freire, E M X; Vasconcellos, A

    2008-02-01

    The relationship between pentastomids and two Colubridae species, Phillodryas nattereri Steindachner, 1870 and Oxybelis aeneus (Wagler, 1824), were investigated in the federal government's reserve Estação Ecológica do Seridó (ESEC, Seridó) situated at lat 6 degrees 35'-40' S and long 37 degrees 15'-20 W in the municipality of Serra Negra do Norte, state of Rio Grande do Norte, Northeast Brazil and run by IBAMA (the Brazilian Institute for the Environment and Natural Resources). Throughout 2005, 26 specimens of snakes, 13 of P. nattereri and 13 of O. aeneus were collected. After anatomical dissection and laboratorial examination of the snakes respiratory tracts, P. nattereri was found to be parasitized by two species of pentastomids: Cephalobaena tetrapoda Heymons, 1922 with a prevalence of 30.8% and a mean intensity of infection of 51.5 +/- 32.7 (range 3-147), and Raillietiella furcocerca (Diesing, 1863) which had a prevalence of 7.7% and a mean intensity of infection of 1.0. Only one female of O. aeneus was found to be infected by C. tetrapoda, with a prevalence of 7.7% and mean intensity of infection of 2.0. There was no significant relationship between size of snout-vent length (SVL) and intensity of infection in the specimens investigated here. The two individuals of P. nattereri infected by more than 40 specimens of pentastomids had their lungs completely infected including the pulmonary peritoneum and trachea. It is noteworthy that the hosts had their lung tissues partially destroyed with apparent haemorrhage, and the trabecular structure of their lungs was also destroyed. The contrasting rates of infection estimated here may be related to differences in foraging strategies, in diet, and habitat selection carried out by individuals of P. nattereri and O. aeneus.

  3. The sixth sense in mammalian forerunners: Variability of the parietal foramen and the evolution of the pineal eye in South African Permo-Triassic eutheriodont therapsids

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    Julien Benoit

    2016-12-01

    Full Text Available In some extant ectotherms, the third eye (or pineal eye is a photosensitive organ located in the parietal foramen on the midline of the skull roof. The pineal eye sends information regarding exposure to sunlight to the pineal complex, a region of the brain devoted to the regulation of body temperature, reproductive synchrony, and biological rhythms. The parietal foramen is absent in mammals but present in most of the closest extinct relatives of mammals, the Therapsida. A broad ranging survey of the occurrence and size of the parietal foramen in different South African therapsid taxa demonstrates that through time the parietal foramen tends, in a convergent manner, to become smaller and is absent more frequently in eutherocephalians (Akidnognathiidae, Whaitsiidae, and Baurioidea and non-mammaliaform eucynodonts. Among the latter, the Probainognathia, the lineage leading to mammaliaforms, are the only one to achieve the complete loss of the parietal foramen. These results suggest a gradual and convergent loss of the photoreceptive function of the pineal organ and degeneration of the third eye. Given the role of the pineal organ to achieve fine-tuned thermoregulation in ectotherms (i.e., “cold-blooded” vertebrates, the gradual loss of the parietal foramen through time in the Karoo stratigraphic succession may be correlated with the transition from a mesothermic metabolism to a high metabolic rate (endothermy in mammalian ancestry. The appearance in the eye of melanopsin-containing retinal ganglion cells replacing the photoreceptive role of the pineal eye could also have accompanied its loss.

  4. Post-Jurassic mammal-like reptile from the Palaeocene.

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    Fox, R C; Youzwyshyn, G P; Krause, D W

    1992-07-16

    Mammal-like reptiles of the order Therapsida document the emergence of mammals from more primitive synapsids and are of unique zoological and palaeontological interest on that account. Therapsids, first appearing in the Early Permian, were thought to become extinct in the Middle Jurassic, soon after the Late Triassic origin of mammals. Here, however, we report the discovery of a therapsid from the late Palaeocene, 100 million years younger than the youngest previous occurrence of the order. This discovery nearly doubles the stratigraphic range of therapsids and furnishes their first record from the Cenozoic. The documenting fossils, an incomplete dentary containing three teeth, and four isolated teeth from other, conspecific individuals (Fig. 1), are from the Paskapoo Formation, at Cochrane, Alberta, Canada, from beds yielding a diverse mammalian fauna of early Tiffanian age. These specimens are catalogued in the collections of the University of Alberta Laboratory for Vertebrate Paleontology (UALVP) and provide the basis for a new taxon, as named and described below: (see text)

  5. An early geikiid dicynodont from the Tropidostoma Assemblage Zone (late Permian) of South Africa

    Science.gov (United States)

    Smith, Roger M.H.

    2017-01-01

    Based on specimens previously identified as Tropidostoma, a new taxon of dicynodont (Bulbasaurus phylloxyron gen. et sp. nov.) from the Karoo Basin of South Africa is described. Bulbasaurus is a medium-sized dicynodont (maximum dorsal skull length 16.0 cm) restricted to the Tropidostoma Assemblage Zone (early Lopingian) of the Beaufort Group. Bulbasaurus can be distinguished from Tropidostoma by an array of characters including the presence of a tall, sharp premaxillary ridge, large, rugose, nearly-confluent nasal bosses, a nasofrontal ridge, massive tusks, robust pterygoids, prominently twisted subtemporal bar, and absence of a distinct postfrontal. Inclusion of Bulbasaurus in a phylogenetic analysis of anomodont therapsids recovers it as a member of Geikiidae, a clade of otherwise later Permian dicynodonts such as Aulacephalodon and Pelanomodon. Bulbasaurus exhibits many of the characters typical of adult Aulacephalodon, but at substantially smaller skull size (these characters are absent in comparably-sized Aulacephalodon juveniles), suggesting that the evolution of typical geikiid morphology preceded gigantism in the clade. Bulbasaurus is the earliest known geikiid and the only member of the group known from the Tropidostoma Assemblage Zone; discovery of this taxon shortens a perplexing ghost lineage and indicates that abundant clades from the later Permian of South Africa (e.g., Geikiidae, Dicynodontoidea) may have originated as rare components of earlier Karoo assemblage zones. PMID:28168104

  6. Nocturnality in synapsids predates the origin of mammals by over 100 million years.

    Science.gov (United States)

    Angielczyk, K D; Schmitz, L

    2014-10-22

    Nocturnality is widespread among extant mammals and often considered the ancestral behavioural pattern for all mammals. However, mammals are nested within a larger clade, Synapsida, and non-mammalian synapsids comprise a rich phylogenetic, morphological and ecological diversity. Even though non-mammalian synapsids potentially could elucidate the early evolution of diel activity patterns and enrich the understanding of synapsid palaeobiology, data on their diel activity are currently unavailable. Using scleral ring and orbit dimensions, we demonstrate that nocturnal activity was not an innovation unique to mammals but a character that appeared much earlier in synapsid history, possibly several times independently. The 24 Carboniferous to Jurassic non-mammalian synapsid species in our sample featured eye morphologies consistent with all major diel activity patterns, with examples of nocturnality as old as the Late Carboniferous (ca 300 Ma). Carnivores such as Sphenacodon ferox and Dimetrodon milleri, but also the herbivorous cynodont Tritylodon longaevus were likely nocturnal, whereas most of the anomodont herbivores are reconstructed as diurnal. Recognizing the complexity of diel activity patterns in non-mammalian synapsids is an important step towards a more nuanced picture of the evolutionary history of behaviour in the synapsid clade.

  7. Bringing dicynodonts back to life: paleobiology and anatomy of a new emydopoid genus from the Upper Permian of Mozambique.

    Science.gov (United States)

    Castanhinha, Rui; Araújo, Ricardo; Júnior, Luís C; Angielczyk, Kenneth D; Martins, Gabriel G; Martins, Rui M S; Chaouiya, Claudine; Beckmann, Felix; Wilde, Fabian

    2013-01-01

    Dicynodontia represent the most diverse tetrapod group during the Late Permian. They survived the Permo-Triassic extinction and are central to understanding Permo-Triassic terrestrial ecosystems. Although extensively studied, several aspects of dicynodont paleobiology such as, neuroanatomy, inner ear morphology and internal cranial anatomy remain obscure. Here we describe a new dicynodont (Therapsida, Anomodontia) from northern Mozambique: Niassodon mfumukasi gen. et sp. nov. The holotype ML1620 was collected from the Late Permian K5 formation, Metangula Graben, Niassa Province northern Mozambique, an almost completely unexplored basin and country for vertebrate paleontology. Synchrotron radiation based micro-computed tomography (SRµCT), combined with a phylogenetic analysis, demonstrates a set of characters shared with Emydopoidea. All individual bones were digitally segmented allowing a 3D visualization of each element. In addition, we reconstructed the osseous labyrinth, endocast, cranial nerves and vasculature. The brain is narrow and the cerebellum is broader than the forebrain, resembling the conservative, "reptilian-grade" morphology of other non-mammalian therapsids, but the enlarged paraflocculi occupy the same relative volume as in birds. The orientation of the horizontal semicircular canals indicates a slightly more dorsally tilted head posture than previously assumed in other dicynodonts. In addition, synchrotron data shows a secondary center of ossification in the femur. Thus ML1620 represents, to our knowledge, the oldest fossil evidence of a secondary center of ossification, pushing back the evolutionary origins of this feature. The fact that the specimen represents a new species indicates that the Late Permian tetrapod fauna of east Africa is still incompletely known.

  8. Bringing dicynodonts back to life: paleobiology and anatomy of a new emydopoid genus from the Upper Permian of Mozambique.

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    Rui Castanhinha

    Full Text Available Dicynodontia represent the most diverse tetrapod group during the Late Permian. They survived the Permo-Triassic extinction and are central to understanding Permo-Triassic terrestrial ecosystems. Although extensively studied, several aspects of dicynodont paleobiology such as, neuroanatomy, inner ear morphology and internal cranial anatomy remain obscure. Here we describe a new dicynodont (Therapsida, Anomodontia from northern Mozambique: Niassodon mfumukasi gen. et sp. nov. The holotype ML1620 was collected from the Late Permian K5 formation, Metangula Graben, Niassa Province northern Mozambique, an almost completely unexplored basin and country for vertebrate paleontology. Synchrotron radiation based micro-computed tomography (SRµCT, combined with a phylogenetic analysis, demonstrates a set of characters shared with Emydopoidea. All individual bones were digitally segmented allowing a 3D visualization of each element. In addition, we reconstructed the osseous labyrinth, endocast, cranial nerves and vasculature. The brain is narrow and the cerebellum is broader than the forebrain, resembling the conservative, "reptilian-grade" morphology of other non-mammalian therapsids, but the enlarged paraflocculi occupy the same relative volume as in birds. The orientation of the horizontal semicircular canals indicates a slightly more dorsally tilted head posture than previously assumed in other dicynodonts. In addition, synchrotron data shows a secondary center of ossification in the femur. Thus ML1620 represents, to our knowledge, the oldest fossil evidence of a secondary center of ossification, pushing back the evolutionary origins of this feature. The fact that the specimen represents a new species indicates that the Late Permian tetrapod fauna of east Africa is still incompletely known.

  9. Confusing dinosaurs with mammals: tetrapod phylogenetics and anatomical terminology in the world of homology.

    Science.gov (United States)

    Harris, Jerald D

    2004-12-01

    At present, three different systems of anatomical nomenclature are available to researchers describing new tetrapod taxa: a nonstandardized traditional system erected in part by Sir Richard Owen and subsequently elaborated by Alfred Romer; a standardized system created for avians, the Nomina Anatomica Avium (NAA); and a standardized system for extant (crown-group) mammals, the Nomina Anatomica Veterinaria (NAV). Conserved homologous structures widely distributed within the Tetrapoda are often granted different names in each system. The recent shift toward a phylogenetic system based on homology requires a concomitant shift toward a single nomenclatural system also based on both evolutionary and functional morphological homology. Standardized terms employed in the NAA and NAV should be perpetuated as far as possible basally in their respective phylogenies. Thus, NAA terms apply to nonavian archosaurs (or even all diapsids) and NAV terms apply to noncrown-group mammals and more basal synapsids. Taxa equally distant from both avians and crown-group mammals may maintain the traditional nonstandardized terminology until a universal anatomical nomenclature for all tetrapods is constructed.

  10. Coelacanths as 'almost living fossils’

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    Lionel eCavin

    2014-08-01

    Full Text Available Since its usage by Darwin in 1859, the concept of ‘living fossil’ has undergone multiple definitions and has been much discussed and criticized. Soon after its discovery in 1938, the coelacanth Latimeria was regarded as the iconic example of a ‘living fossil’. Several morphological studies have shown that the coelacanth lineage (Actinistia has not displayed critical morphological transformation during its evolutionary history and molecular studies have revealed a low substitution rate for Latimeria, indicating a slow genetic evolution. This statement, however, has been recently questioned by arguing that the low substitution rate was not real, and that the slow morphological evolution of actinistians was not supported by paleontological evidence. The assessment of morphological transformation among three vertebrate lineages during a time interval of circa 400 million years shows that the morphological disparity of coelacanths is much more reduced than the morphological disparity of Actinopterygii and Tetrapoda. These results support the idea that living coelacanths are singular organisms among the living world.

  11. Suspension and optical properties of the crystalline lens in the eyes of basal vertebrates.

    Science.gov (United States)

    Kröger, Ronald H H; Gustafsson, Ola S E; Tuminaite, Inga

    2014-06-01

    We have investigated the apparatus suspending the crystalline lens in the eyes of basal vertebrates. Data are presented for Holocephali (Chondrichthyes) and the actinopterygians Polypteriformes, Polyodontidae (Acipenseriformes), Lepisosteiformes, Amiiformes, and one teleost species, the banded archerfish (Toxotes jaculatrix). We also studied the optical properties of the lens in Polypteriformes, Lepisosteiformes, and the archerfish. Together with previously published results, our findings show that there are three basic types of lens suspension in vertebrates. These are i) a rotationally symmetric suspension (Petromyzontida, lampreys; Ceratodontiformes, lungfishes; Tetrapoda), ii) a suspension with a dorso-ventral axis of symmetry and a ventral papilla (all Chondrichthyes and Acipenseriformes), and iii) an asymmetric suspension with a ventral muscle and a varying number of ligaments (all Actinopterygii except for Acipenseriformes). Large eyes with presumably high spatial resolution have evolved in all groups. Multifocal lenses creating well-focused color images are also present in all groups studied. Stable and exact positioning of the lens, in many cases in combination with accommodative changes in lens position or shape, is achieved by all three types of lens suspension. It is somewhat surprising that lens suspensions are strikingly similar in Chondrichthyes and Acipenseriformes (Actinopterygii), while the suspension apparatus in Polypteriformes, usually being regarded as an actinopterygian group more basal than Acipenseriformes, are considerably more teleostean-like. This study completes a series of investigations on lens suspensions in nontetrapod vertebrates, covering all major groups except for the rare and highly derived coelacanths.

  12. Basal Gnathostomes Provide Unique Insights into the Evolution of Vitamin B12 Binders

    Science.gov (United States)

    Lopes-Marques, Mónica; Ruivo, Raquel; Delgado, Inês; Wilson, Jonathan M.; Aluru, Neelakanteswar; Castro, L. Filipe C.

    2015-01-01

    The uptake and transport of vitamin B12 (cobalamin; Cbl) in mammals involves a refined system with three evolutionarily related transporters: transcobalamin 1 (Tcn1), transcobalamin 2 (Tcn2), and the gastric intrinsic factor (Gif). Teleosts have a single documented binder with intermediate features to the human counterparts. Consequently, it has been proposed that the expansion of Cbl binders occurred after the separation of Actinopterygians. Here, we demonstrate that the diversification of this gene family took place earlier in gnathostome ancestry. Our data indicates the presence of single copy orthologs of the Sarcopterygii/Tetrapoda duplicates Tcn1 and Gif, and Tcn2, in Chondrichthyes. In addition, a highly divergent Cbl binder was found in the Elasmobranchii. We unveil a complex scenario forged by genome, tandem duplications and lineage-specific gene loss. Our findings suggest that from an ancestral transporter, exhibiting large spectrum and high affinity binding, highly specific Cbl transporters emerged through gene duplication and mutations at the binding pocket. PMID:25552533

  13. Functional morphology and evolution of aspiration breathing in tetrapods.

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    Brainerd, Elizabeth L; Owerkowicz, Tomasz

    2006-11-01

    In the evolution of aspiration breathing, the responsibility for lung ventilation gradually shifted from the hyobranchial to the axial musculoskeletal system, with axial muscles taking over exhalation first, at the base of Tetrapoda, and then inhalation as well at the base of Amniota. This shift from hyobranchial to axial breathing freed the tongue and head to adapt to more diverse feeding styles, but generated a mechanical conflict between costal ventilation and high-speed locomotion. Some "lizards" (non-serpentine squamates) have been shown to circumvent this speed-dependent axial constraint with accessory gular pumping during locomotion, and here we present a new survey of gular pumping behavior in the tuatara and 40 lizard species. We observed gular pumping behavior in 32 of the 40 lizards and in the tuatara, indicating that the ability to inflate the lungs by gular pumping is a shared-derived character for Lepidosauria. Gular pump breathing in lepidosaurs may be homologous with buccal pumping in amphibians, but non-ventilatory buccal oscillation and gular flutter have persisted throughout amniote evolution and gular pumping may have evolved independently by modification of buccal oscillation. In addition to gular pumping in some lizards, three other innovations have evolved repeatedly in the major amniote clades to circumvent the speed-dependent axial constraint: accessory inspiratory muscles (mammals, crocodylians and turtles), changing locomotor posture (mammals and birds) and respiratory-locomotor phase coupling to reduce the mechanical conflict between aspiration breathing and locomotion (mammals and birds).

  14. Major African contributions to Palaeozoic and Mesozoic vertebrate palaeontology

    Science.gov (United States)

    Durand, J. F.

    2005-10-01

    Over more than two centuries, Africa has been an important source of knowledge with regard to the origins, evolution and distribution of important animal taxa. Not only did Africa south of the Sahara contain a second zoogeographical region virtually unknown four centuries ago, but also gave the world the first insight into the palaeontological wealth and the existence of Gondwana. The section on Agnatha includes a discussion on conodonts from South Africa, considered to be the some of the oldest and best-preserved vertebrate fossils in the world. The section on the Gnathostomata includes a very brief overview of the most important fish taxa from the Palaeozoic to Mesozoic of Africa. The section on the Tetrapoda includes an overview of the major taxa found in the fossil record of the Palaeozoic and Mesozoic of Africa. The Permian and Triassic tetrapod fossils that indicate the evolution and radiation of the parareptiles, eureptiles and synapsids are highlighted. The most important vertebrate fossils from Africa that contributed to our understanding of the radiation of evolutionary important groups such as the fish, tetrapods, tortoises, snakes, crocodiles, dinosaurs and mammals are discussed. The Jurassic and Cretaceous assemblages containing dinosaur and mammal remains, deposited after the break up of Gondwana, are discussed. Finally a perspective on the importance of Africa as fossil repository and the limitations of palaeontological endeavour in Africa is given.

  15. PRIMITIVISME IKAN POLYPTERUS SEBAGAI WARISAN MANUSIA MODERN

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    Media Fitri Isma Nugraha

    2010-12-01

    Full Text Available Tinjauan ini mensintesa historis dan diversitas ikan purba Polypterus yang berasal dari Afrika sebagai komoditi budidaya ikan hias. Sejarah evolusinya sangat unik, muncul sejak pertengahan Miocen (10 juta tahun, hubungan parentalnya berada pada posisi transisional sister-takson antara Teleostei dan Tetrapoda. Primitivismenya menyisakan divergensi momental sains hampir satu abad dalam determinasi dimorfisme seksualnya. Bersifat nokturnal, tahan terhadap kondisi habitat ekstrim tetapi mudah dibudidayakan. Polypterus jantan memiliki sirip anal tebal dan condong ke hipural konjungsi sirip ekor. Seekor betina mampu bertelur 100–300 butir dan menetas kurang dari 3 hari. Benih Polypterus sudah dapat beradaptasi dengan pakan tambahan sekitar 10 hari pasca menetas, dan dalam perkembangan gonad jantan dan betina akan terbentuk sempurna setelah berumur 10 bulan. Fosil hidup Polypterus telah menjadi warisan dunia, adopsi dan asuhan penggemarnya tersebar ke-5 benua, dapat dilaporkan bahwa harga per ekor dipatok variatif antara US$40–US$70. Kegemaran kita membudidayakannya, berarti telah menyelamatkan populasi ikan ini agar terhindar dari kepunahan. Atas dasar konsesi dan semangat terhadap warisan spesies dunia itu, BRBIH Depok telah mengoleksi dan sukses memproduksi satu sub spesies, satu varian intergenetik-albino dari populasi Polypterus senegalus senegalus dan 3 spesies intragenerik lainnya.

  16. Structural evolution and tissue-specific expression of tetrapod-specific second isoform of secretory pathway Ca{sup 2+}-ATPase

    Energy Technology Data Exchange (ETDEWEB)

    Pestov, Nikolay B., E-mail: korn@mail.ibch.ru [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117871 (Russian Federation); Dmitriev, Ruslan I.; Kostina, Maria B. [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117871 (Russian Federation); Korneenko, Tatyana V. [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117871 (Russian Federation); Department of Physiology and Pharmacology, University of Toledo College of Medicine, 3000 Arlington Ave., Toledo, OH 43614 (United States); Shakhparonov, Mikhail I. [Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117871 (Russian Federation); Modyanov, Nikolai N., E-mail: nikolai.modyanov@utoledo.edu [Department of Physiology and Pharmacology, University of Toledo College of Medicine, 3000 Arlington Ave., Toledo, OH 43614 (United States)

    2012-01-27

    Highlights: Black-Right-Pointing-Pointer Full-length secretory pathway Ca-ATPase (SPCA2) cloned from rat duodenum. Black-Right-Pointing-Pointer ATP2C2 gene (encoding SPCA2) exists only in genomes of Tetrapoda. Black-Right-Pointing-Pointer Rat and pig SPCA2 are expressed in intestines, lung and some secretory glands. Black-Right-Pointing-Pointer Subcellular localization of SPCA2 may depend on tissue type. Black-Right-Pointing-Pointer In rat duodenum, SPCA2 is localized in plasma membrane-associated compartments. -- Abstract: Secretory pathway Ca-ATPases are less characterized mammalian calcium pumps than plasma membrane Ca-ATPases and sarco-endoplasmic reticulum Ca-ATPases. Here we report analysis of molecular evolution, alternative splicing, tissue-specific expression and subcellular localization of the second isoform of the secretory pathway Ca-ATPase (SPCA2), the product of the ATP2C2 gene. The primary structure of SPCA2 from rat duodenum deduced from full-length transcript contains 944 amino acid residues, and exhibits 65% sequence identity with known SPCA1. The rat SPCA2 sequence is also highly homologous to putative human protein KIAA0703, however, the latter seems to have an aberrant N-terminus originating from intron 2. The tissue-specificity of SPCA2 expression is different from ubiquitous SPCA1. Rat SPCA2 transcripts were detected predominantly in gastrointestinal tract, lung, trachea, lactating mammary gland, skin and preputial gland. In the newborn pig, the expression profile is very similar with one remarkable exception: porcine bulbourethral gland gave the strongest signal. Upon overexpression in cultured cells, SPCA2 shows an intracellular distribution with remarkable enrichment in Golgi. However, in vivo SPCA2 may be localized in compartments that differ among various tissues: it is intracellular in epidermis, but enriched in plasma membranes of the intestinal epithelium. Analysis of SPCA2 sequences from various vertebrate species argue that ATP2C2

  17. Ação da Musculatura Adutora da Mandíbula em Dicinodontes Triássicos do Sul do Brasil

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    Leonardo Morato

    2007-07-01

    Full Text Available São conhecidos, com segurança, três diferentestáxons de dicinodontes para o Triássico doRio Grande do Sul, representados pelos gênerosStahleckeria Huene, 1934, Dinodontosaurus Romer,1943 e Jachaleria Bonaparte, 1970. Dinodontosauruse Stahleckeria coexistiram temporalmente naCenozona de Therapsida (Mesotriássico, Ladinianoenquanto Jachaleria era a única forma de dicinodontena Cenozona de Mamaliamorpha (Neotriássico,Eonoriano?. Dos três, apenas Dinodontosaurusapresenta o par de presas caniniformes que caracterizao grupo, sendo as demais formas totalmenteedentadas, mas esta característica está mais provavelmentevinculada à ornamentação e não interferena discussão mecânica aqui proposta. A robustez dasmandíbulas e a eficiência da musculatura empregadano ciclo mastigatório podem ser reflexos do grau deprocessamento oral e da resistência do material a seringerido. Nesse sentido, os três taxa de dicinodontessupracitados foram comparados quanto às variaçõesda morfologia craniana, discutindo os modos comque estas afetam o comprimento das fibras muscularese os ângulos de inserção da musculatura nas mandíbulas,indicando a dimensão dos braços de alavancadas forças exercidas por esses músculos em relaçãoà articulação crânio-mandibular. Assim, pode-seter um quadro das vantagens mecânicas de diferentesarranjos musculares. Optou-se por realizar umaanálise da ação da mandíbula como um corpo livre,tratando todas as mandíbulas com o mesmo comprimento,a fim de que a dimensão do braço de alavancadas forças executadas pelos diferentes músculosseja um reflexo direto de suas vantagens mecânicas,quando comparados os mesmos músculos entre doisanimais. Quanto maior o braço de alavanca de umconjunto muscular de um animal em relação a outro,menor o esforço necessário para o primeiro executara ação. Utilizando como referência uma orientaçãohorizontal do palato e basicrânio, ao compararem-seos crânios dos tr

  18. Programa de Pós-Graduação em Geologia - Dissertações Defendidas 1998 - Mestrado - Instituto de Geociências - Universidade Federal do Rio de Janeiro

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    1998-01-01

    Anuário do Instituto de Geociências - UFRJ Volume 21 / 1998 do Paraná, localizada na região de Pinheiros, pertencentes ao município de Candelária, Rio Grande do Sul. Os coprólitos estudados estão relacionados à paleoherpetofauna da cenozona Therapsida e permitem inferir sobre paleoecologia e o paleoclima da região durante este momento do Triássico. As 22 amostras são compostas por um conjunto de 50 massas aglomeradas ou isoladas, classificadas em tipos ovóides e cilíndricos. Os coprólitos foram coletados em quatro afloramentos, que pertencem ao conjunto de ravinas denominadas regionalmente de sangas. Nestes afloramentos os restos de répteis mamaliformes (dicinodontes e cinodontes e arcosssauros (tecodontes encontram-se fartamente distribuídos em vários níveis do perfil, sem qualquer zona preferencial de concentração. As amostras foram classificadas pelas formas e descritas pelos aspectos externos (cor, polaridade e textura da superfície e internos, através da utilização de diferentes análises de raios-x (emissão, difratometria e fluorescência e corte de lâmina. A avaliação dos aspectos quantitativos das amostras foram realizados através da aplicação estatística do cálculo da freqüência de classes e do coeficiente de variação, necessários na caracterização e investigação das afinidades dos grupamentos. Entre os aspectos apresentados em superfície, os resultados de agretamento e de coprofagia, informam sobre condições paleobiológicas e paleoclimáticas no momento em que os coprólitos foram produzidos. Os coprólitos de forma ovóide caracterizados pela maior variação do tamanho, gretas e estruturas vegetais, confirmam aspectos de afinidade com excrementos de dieta herbívora. As formas cilíndricas de peso e tamanho mais uniformes são caracterizadas pelo alto grau de compactação interna, relacionando estes excrementos como provenientes de dieta carnívora ou omnívora. A composição mineralógica apresentada na an