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Ji Cheng - One of the best experts on this subject based on the ideXlab platform.
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THE EARLY TRIASSIC EOSAUROPTERYGIAN MAJIASHANOSAURUS DISCOCORACOIDIS, GEN. ET SP NOV (REPTILIA, SAUROPTERYGIA), FROM CHAOHU, ANHUI PROVINCE, PEOPLE'S REPUBLIC OF CHINA
journal of vertebrate paleontology, 2014Co-Authors: Jiang Da-yong, Motani Ryosuke, Tintori Andrea, Rieppel Olivier, Chen Guan-bao, Huang Jian-dong, Zhang Rong, Sun Zuo-yu, Ji ChengAbstract:Records of Early Triassic marine reptiles, when they first emerged after the end Permian mass extinction, are rare. During an excavation at Majiashan, Chaohu, Anhui Province, a new sauropterygian specimen was found co-occurring with the ichthyopterygian Chaohusaurus from the Upper Member of the Nanlinghu Formation, of Olenekian (Spathian, Early Triassic) age, for which a new taxon, Majiashanosaurus discocoracoidis, gen. et sp. nov., is erected. This skeleton is exposed in ventral view, with the last three cervical vertebrae together with 19 dorsal, three sacral, and more than 18 caudal vertebrae preserved. The cervical centra are keeled ventrally, and cervical ribs are double-headed, carrying a free anterior process. The transverse processes of the dorsal vertebrae are not distinctively elongated. The dorsal ribs are single-headed, and the clavicles articulate on the anteromedial aspect of the scapula. The humerus is curved. These features allow assignment to a new sauropterygian taxon. The Interclavicle has no posterior process, and the scapula is of typical eosauropterygian shape, with a broad and ventrally expanded glenoidal portion that is separated from a narrow posterodorsal blade by a distinct constriction. The coracoid is round and plate-like without a waist. This feature is different from that of all other known eosauropterygians, but resembles that of placodonts.SUPPLEMENTAL DATASupplemental materials are available for this article for free at www.tandfonline.com/UJVPPaleontologySCI(E)1ARTICLEdjiang@pku.edu.cn; rmotani@ucdavis.edu; andrea.tintori@unimi.it; orieppel@fieldmuseum.org51044-10523
Jiang Da-yong - One of the best experts on this subject based on the ideXlab platform.
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THE EARLY TRIASSIC EOSAUROPTERYGIAN MAJIASHANOSAURUS DISCOCORACOIDIS, GEN. ET SP NOV (REPTILIA, SAUROPTERYGIA), FROM CHAOHU, ANHUI PROVINCE, PEOPLE'S REPUBLIC OF CHINA
journal of vertebrate paleontology, 2014Co-Authors: Jiang Da-yong, Motani Ryosuke, Tintori Andrea, Rieppel Olivier, Chen Guan-bao, Huang Jian-dong, Zhang Rong, Sun Zuo-yu, Ji ChengAbstract:Records of Early Triassic marine reptiles, when they first emerged after the end Permian mass extinction, are rare. During an excavation at Majiashan, Chaohu, Anhui Province, a new sauropterygian specimen was found co-occurring with the ichthyopterygian Chaohusaurus from the Upper Member of the Nanlinghu Formation, of Olenekian (Spathian, Early Triassic) age, for which a new taxon, Majiashanosaurus discocoracoidis, gen. et sp. nov., is erected. This skeleton is exposed in ventral view, with the last three cervical vertebrae together with 19 dorsal, three sacral, and more than 18 caudal vertebrae preserved. The cervical centra are keeled ventrally, and cervical ribs are double-headed, carrying a free anterior process. The transverse processes of the dorsal vertebrae are not distinctively elongated. The dorsal ribs are single-headed, and the clavicles articulate on the anteromedial aspect of the scapula. The humerus is curved. These features allow assignment to a new sauropterygian taxon. The Interclavicle has no posterior process, and the scapula is of typical eosauropterygian shape, with a broad and ventrally expanded glenoidal portion that is separated from a narrow posterodorsal blade by a distinct constriction. The coracoid is round and plate-like without a waist. This feature is different from that of all other known eosauropterygians, but resembles that of placodonts.SUPPLEMENTAL DATASupplemental materials are available for this article for free at www.tandfonline.com/UJVPPaleontologySCI(E)1ARTICLEdjiang@pku.edu.cn; rmotani@ucdavis.edu; andrea.tintori@unimi.it; orieppel@fieldmuseum.org51044-10523
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A new species of Largocephalosaurus (Diapsida: Saurosphargidae), with implications for the morphological diversity and phylogeny of the group
geological magazine, 2014Co-Authors: Li Chun, Jiang Da-yong, Cheng Long, Wu Xiao-chun, Rieppel OlivierAbstract:Largocephalosaurus polycarpon Cheng et al. 2012a was erected after the study of the skull and some parts of a skeleton and considered to be an eosauropterygian. Here we describe a new species of the genus, Largocephalosaurus qianensis, based on three specimens. The new species provides many anatomical details which were described only briefly or not at all in the type species, and clearly indicates that Largocephalosaurus is a saurosphargid. It differs from the type species mainly in having three premaxillary teeth, a very short retroarticular process, a large pineal foramen, two sacral vertebrae, and elongated small granular osteoderms mixed with some large ones along the lateral most side of the body. With additional information from the new species, we revise the diagnosis and the phylogenetic relationships of Largocephalosaurus and clarify a set of diagnostic features for the Saurosphargidae Li et al. 2011. Largocephalosaurus is characterized primarily by an oval supratemporal fenestra, an elongate dorsal rib-basket', a narrow and elongate transverse process of the dorsal vertebrae, and the lack of a complete dorsal carapace of osteoderms. The Saurosphargidae is distinct mainly in having a retracted external naris, a jugal-squamosal contact, a large supratemporal extensively contacting the quadrate shaft, a leaf-like tooth crown with convex labial surface and concave lingual surface, a closed dorsal rib-basket', many dorsal osteoderms, a large boomerang-like or atypical T-shaped Interclavicle. Current evidence suggests that the Saurosphargidae is the sister-group of the Sauropterygia and that Largocephalosaurus is the sister-group of the Saurosphargis-Sinosaurosphargis clade within the family.Geosciences, MultidisciplinarySCI(E)6ARTICLElichun@ivpp.ac.cn; xwu@mus-nature.ca1100-12015
Warren Anne - One of the best experts on this subject based on the ideXlab platform.
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Gerrothorax pulcherrimus from the upper Triassic Fleming Fjord formation of East Greenland and a reassessment of head lifting in temnospondyl feeding
'Society of Vertebrate Paleontology', 2008Co-Authors: Jenkins Farish, Gatesy Stephen, Shubin, Neil H., Warren AnneAbstract:The plagiosaurine Gerrothorax pulcherrimus, a ubiquitous faunal component of the Fleming Fjord Formation, is recognized by tubercular ornamentation, contact between the postfrontal and supratemporal, at least two tooth rows on the posterior coronoid, and a posttemporal fenestra that is small or absent. Gerrothorax pulcherrimus also possesses a derived pectoral morphology that includes an interlocking claviculocleithral complex and an Interclavicle with paired posterolateral projections and a transversely truncated posterior margin. Gerrothorax pustuloglomeratus is a junior synonym of G. pulcherrimus; other Gerrothorax species cannot be differentiated from G. pulcherrimus. Flat-headed temnospondyls have been interpreted as having achieved a large gape by raising the skull rather than by lowering the jaw. No detailed, corroborating anatomical evidence from the atlanto-occipital joint, however, has ever been adduced. In G. pulcherrimus the widths of the atlantal and condylar facets are comparable, but dorsoventrally the condylar facets are 45% longer than the comparable dimension of the atlantal facets. Elevation of the skull occurred by atlanto-occipital rotation, and was facilitated by a radius of curvature of the dorsal part of the condylar facets that is shorter than that of the inferior part. From a resting, closed mouth position, G. pulcherrimus was capable of elevating the skull through an excursion of approximately 50°, a movement that rotated the quadrate forward and protruded the lower jaw. An elongate, broadly open neural canal in the atlanto-occipital region, and dorsal displacement of the occipital condyles, are related to relieving the spinal medulla of the sharp angular deformation that head lifting might entail.Organismic and Evolutionary Biolog
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Immaturity vs paedomorphism: a rhinesuchid stereospondyl postcranium from the Upper Permian of South Africa
BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 2004Co-Authors: Pawley Kat, Warren AnneAbstract:The postcranial skeleton of a medium-sized rhinesuchid from the Late Permian Dicynodon Assemblage Zone of South Africa is described. The well-preserved, articulated specimen consists of a partial skull, vertebral column and ribs, pectoral girdle, proximal limb elements, and ventral scales. Interesting features rarely preserved in stereospondyls include the extensive ventral scales and the pectinate anterior border of the Interclavicle. SAM-PK-K10021 is of an average size for a rhinesuchid, but possesses a poorly ossified postcranial skeleton in comparison to larger rhinesuchid specimens. The scapulocoracoid lacks an ossified coracoid plate, the humerus lacks a supinator process, and the femur lacks a well-developed internal trochanter and adductor blade. Despite its relatively large size, SAM-PK-K10021 is an immature stage of a large rhinesuchid, thus contributing to our knowledge of the changes to the postcranial skeleton that occur during ontogeny. The assessment of heterochronic processes, especially paedomorphism, in the postcranial skeleton of temnospondyls, and the implications for cladistic analysis, are discussed
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Immaturity vs paedomorphism: a rhinesuchid stereospondyl postcranium from the Upper Permian of South Africa
Bernard Price Institute for Palaeontological Research, 2004Co-Authors: Pawley Kat, Warren AnneAbstract:The postcranial skeleton of a medium-sized rhinesuchid from the Late Permian Dicynodon Assemblage Zone of South Africa is described. The well-preserved, articulated specimen consists of a partial skull, vertebral column and ribs, pectoral girdle, proximal limb elements, and ventral scales. Interesting features rarely preserved in stereospondyls include the extensive ventral scales and the pectinate anterior border of the Interclavicle. SAM-PK-K10021 is of an average size for a rhinesuchid, but possesses a poorly ossified postcranial skeleton in comparison to larger rhinesuchid specimens. The scapulocoracoid lacks an ossified coracoid plate, the humerus lacks a supinator process, and the femur lacks a well-developed internal trochanter and adductor blade. Despite its relatively large size, SAM-PK-K10021 is an immature stage of a large rhinesuchid, thus contributing to our knowledge of the changes to the postcranial skeleton that occur during ontogeny. The assessment of heterochronic processes, especially paedomorphism, in the postcranial skeleton of temnospondyls, and the implications for cladistic analysis, are discussed.Palaeo-anthropology Scientific Trus
Rieppel Olivier - One of the best experts on this subject based on the ideXlab platform.
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THE EARLY TRIASSIC EOSAUROPTERYGIAN MAJIASHANOSAURUS DISCOCORACOIDIS, GEN. ET SP NOV (REPTILIA, SAUROPTERYGIA), FROM CHAOHU, ANHUI PROVINCE, PEOPLE'S REPUBLIC OF CHINA
journal of vertebrate paleontology, 2014Co-Authors: Jiang Da-yong, Motani Ryosuke, Tintori Andrea, Rieppel Olivier, Chen Guan-bao, Huang Jian-dong, Zhang Rong, Sun Zuo-yu, Ji ChengAbstract:Records of Early Triassic marine reptiles, when they first emerged after the end Permian mass extinction, are rare. During an excavation at Majiashan, Chaohu, Anhui Province, a new sauropterygian specimen was found co-occurring with the ichthyopterygian Chaohusaurus from the Upper Member of the Nanlinghu Formation, of Olenekian (Spathian, Early Triassic) age, for which a new taxon, Majiashanosaurus discocoracoidis, gen. et sp. nov., is erected. This skeleton is exposed in ventral view, with the last three cervical vertebrae together with 19 dorsal, three sacral, and more than 18 caudal vertebrae preserved. The cervical centra are keeled ventrally, and cervical ribs are double-headed, carrying a free anterior process. The transverse processes of the dorsal vertebrae are not distinctively elongated. The dorsal ribs are single-headed, and the clavicles articulate on the anteromedial aspect of the scapula. The humerus is curved. These features allow assignment to a new sauropterygian taxon. The Interclavicle has no posterior process, and the scapula is of typical eosauropterygian shape, with a broad and ventrally expanded glenoidal portion that is separated from a narrow posterodorsal blade by a distinct constriction. The coracoid is round and plate-like without a waist. This feature is different from that of all other known eosauropterygians, but resembles that of placodonts.SUPPLEMENTAL DATASupplemental materials are available for this article for free at www.tandfonline.com/UJVPPaleontologySCI(E)1ARTICLEdjiang@pku.edu.cn; rmotani@ucdavis.edu; andrea.tintori@unimi.it; orieppel@fieldmuseum.org51044-10523
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A new species of Largocephalosaurus (Diapsida: Saurosphargidae), with implications for the morphological diversity and phylogeny of the group
geological magazine, 2014Co-Authors: Li Chun, Jiang Da-yong, Cheng Long, Wu Xiao-chun, Rieppel OlivierAbstract:Largocephalosaurus polycarpon Cheng et al. 2012a was erected after the study of the skull and some parts of a skeleton and considered to be an eosauropterygian. Here we describe a new species of the genus, Largocephalosaurus qianensis, based on three specimens. The new species provides many anatomical details which were described only briefly or not at all in the type species, and clearly indicates that Largocephalosaurus is a saurosphargid. It differs from the type species mainly in having three premaxillary teeth, a very short retroarticular process, a large pineal foramen, two sacral vertebrae, and elongated small granular osteoderms mixed with some large ones along the lateral most side of the body. With additional information from the new species, we revise the diagnosis and the phylogenetic relationships of Largocephalosaurus and clarify a set of diagnostic features for the Saurosphargidae Li et al. 2011. Largocephalosaurus is characterized primarily by an oval supratemporal fenestra, an elongate dorsal rib-basket', a narrow and elongate transverse process of the dorsal vertebrae, and the lack of a complete dorsal carapace of osteoderms. The Saurosphargidae is distinct mainly in having a retracted external naris, a jugal-squamosal contact, a large supratemporal extensively contacting the quadrate shaft, a leaf-like tooth crown with convex labial surface and concave lingual surface, a closed dorsal rib-basket', many dorsal osteoderms, a large boomerang-like or atypical T-shaped Interclavicle. Current evidence suggests that the Saurosphargidae is the sister-group of the Sauropterygia and that Largocephalosaurus is the sister-group of the Saurosphargis-Sinosaurosphargis clade within the family.Geosciences, MultidisciplinarySCI(E)6ARTICLElichun@ivpp.ac.cn; xwu@mus-nature.ca1100-12015
Anne Warren - One of the best experts on this subject based on the ideXlab platform.
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gerrothorax pulcherrimus from the upper triassic fleming fjord formation of east greenland and a reassessment of head lifting in temnospondyl feeding
Journal of Vertebrate Paleontology, 2008Co-Authors: Farish A Jenkins, Neil H Shubin, Stephen M Gatesy, Anne WarrenAbstract:ABSTRACT The plagiosaurine Gerrothorax pulcherrimus, a ubiquitous faunal component of the Fleming Fjord Formation, is recognized by tubercular ornamentation, contact between the postfrontal and supratemporal, at least two tooth rows on the posterior coronoid, and a posttemporal fenestra that is small or absent. Gerrothorax pulcherrimus also possesses a derived pectoral morphology that includes an interlocking claviculocleithral complex and an Interclavicle with paired posterolateral projections and a transversely truncated posterior margin. Gerrothorax pustuloglomeratus is a junior synonym of G. pulcherrimus; other Gerrothorax species cannot be differentiated from G. pulcherrimus. Flat-headed temnospondyls have been interpreted as having achieved a large gape by raising the skull rather than by lowering the jaw. No detailed, corroborating anatomical evidence from the atlanto-occipital joint, however, has ever been adduced. In G. pulcherrimus the widths of the atlantal and condylar facets are comparable, b...