The Experts below are selected from a list of 9 Experts worldwide ranked by ideXlab platform
Xu Xing - One of the best experts on this subject based on the ideXlab platform.
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a new rhamphorhynchid pterosaur from the upper jurassic of xinjiang china and the phylogenetic relationships of basal pterosaurs
Journal of Vertebrate Paleontology, 2010Co-Authors: Brian Andres, James M Clark, Xu XingAbstract:ABSTRACT A new rhamphorhynchid pterosaur species, Sericipterus wucaiwanensis, gen. et sp. nov., is described from the Upper Jurassic part of the Shishugou Formation in the Xinjiang Autonomous Region of northwest China. Pterosaurs from this unit are the earliest and only records of pterosaurs in the Jurassic of northwest China. The individual specimen is one of the largest known among ‘rhamphorhynchoids,’ or non-pterodactyloid pterosaurs. The holotype comprises an associated skeleton of mostly disarticulated, largely three-dimensional material. Although partly crushed, the preservation in this specimen reveals morphology rarely seen in non-pterodactyloid pterosaurs. This includes a distinct cervical Intervertebral Articulation morphology that is proposed to be widespread among the non-pterodactyloids. The skull of this new specimen is most similar to that of other rhamphorhynchids, Angustinaripterus longicephalus and Harpactognathus gentryii, found in terrestrial deposits. A phylogenetic analysis of 18 non...
Brian Andres - One of the best experts on this subject based on the ideXlab platform.
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a new rhamphorhynchid pterosaur from the upper jurassic of xinjiang china and the phylogenetic relationships of basal pterosaurs
Journal of Vertebrate Paleontology, 2010Co-Authors: Brian Andres, James M Clark, Xu XingAbstract:ABSTRACT A new rhamphorhynchid pterosaur species, Sericipterus wucaiwanensis, gen. et sp. nov., is described from the Upper Jurassic part of the Shishugou Formation in the Xinjiang Autonomous Region of northwest China. Pterosaurs from this unit are the earliest and only records of pterosaurs in the Jurassic of northwest China. The individual specimen is one of the largest known among ‘rhamphorhynchoids,’ or non-pterodactyloid pterosaurs. The holotype comprises an associated skeleton of mostly disarticulated, largely three-dimensional material. Although partly crushed, the preservation in this specimen reveals morphology rarely seen in non-pterodactyloid pterosaurs. This includes a distinct cervical Intervertebral Articulation morphology that is proposed to be widespread among the non-pterodactyloids. The skull of this new specimen is most similar to that of other rhamphorhynchids, Angustinaripterus longicephalus and Harpactognathus gentryii, found in terrestrial deposits. A phylogenetic analysis of 18 non...
James M Clark - One of the best experts on this subject based on the ideXlab platform.
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a new rhamphorhynchid pterosaur from the upper jurassic of xinjiang china and the phylogenetic relationships of basal pterosaurs
Journal of Vertebrate Paleontology, 2010Co-Authors: Brian Andres, James M Clark, Xu XingAbstract:ABSTRACT A new rhamphorhynchid pterosaur species, Sericipterus wucaiwanensis, gen. et sp. nov., is described from the Upper Jurassic part of the Shishugou Formation in the Xinjiang Autonomous Region of northwest China. Pterosaurs from this unit are the earliest and only records of pterosaurs in the Jurassic of northwest China. The individual specimen is one of the largest known among ‘rhamphorhynchoids,’ or non-pterodactyloid pterosaurs. The holotype comprises an associated skeleton of mostly disarticulated, largely three-dimensional material. Although partly crushed, the preservation in this specimen reveals morphology rarely seen in non-pterodactyloid pterosaurs. This includes a distinct cervical Intervertebral Articulation morphology that is proposed to be widespread among the non-pterodactyloids. The skull of this new specimen is most similar to that of other rhamphorhynchids, Angustinaripterus longicephalus and Harpactognathus gentryii, found in terrestrial deposits. A phylogenetic analysis of 18 non...
Philippe Wenger - One of the best experts on this subject based on the ideXlab platform.
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modeling Intervertebral Articulation the rotule a doigt mechanical joint rad in birds and mammals
Journal of Anatomy, 2021Co-Authors: Anick Abourachid, Benoit Gagnier, Matthieu Furet, Raphael Cornette, Arnaud Delapre, Remi Hackert, Philippe WengerAbstract:The vertebrate skeleton is composed of articulated bones. Most of the Articulations are classically described using mechanical joints, except the Intervertebral joint. The aim of this study was to identify a joint model with the same mechanical features as the cervical joints. On the neck vertebrae, six articular surfaces participate in the joint: the cranial part of the centrum and the facets of the two prezygapophyses of a vertebra articulate on the caudal part of the centrum and the two articular facets of the postzygapophyses of the previous vertebra. We used the Intervertebral joints of the birds neck to identify the mechanical joint representing Intervertebral linkage. This link was described in the literature as a joint allowing two or three rotations and no translation. These features correspond to the rotule a doigt (RAD) joint, a ball and socket joint with a pin. We compared the RAD joint to the postaxial Intervertebral joints of the avian neck and found it a suitable model to determine the geometrical features involved in the joint mobility. The difference in the angles of virtual axes linking the geometrical center of the centrum to the zygapophysis surfaces determines the mean dorsoventral flexion of the joint. It also helps to limit longitudinal rotation. The orientation of the zygapophysis surfaces determines the range of motion in both dorsoventral and lateral flexion. The overall system prevents dislocation. The model was validated on 13 joints of a vulture neck and 11 joints of a swallow neck and on one joint (C6-C7) in each of three mammal species: the wolf (Canis lupus), mole (Talpa europaea), and human (Homo sapiens). The RAD mechanical joint was found in all vertebral Articulations. This validation of the model on different species shows that the RAD Intervertebral joint model makes it possible to extract the parameters that guide and limit the mobility of the cervical spine from the complex shape of the vertebrae and to compare them in interspecific studies.
Anick Abourachid - One of the best experts on this subject based on the ideXlab platform.
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modeling Intervertebral Articulation the rotule a doigt mechanical joint rad in birds and mammals
Journal of Anatomy, 2021Co-Authors: Anick Abourachid, Benoit Gagnier, Matthieu Furet, Raphael Cornette, Arnaud Delapre, Remi Hackert, Philippe WengerAbstract:The vertebrate skeleton is composed of articulated bones. Most of the Articulations are classically described using mechanical joints, except the Intervertebral joint. The aim of this study was to identify a joint model with the same mechanical features as the cervical joints. On the neck vertebrae, six articular surfaces participate in the joint: the cranial part of the centrum and the facets of the two prezygapophyses of a vertebra articulate on the caudal part of the centrum and the two articular facets of the postzygapophyses of the previous vertebra. We used the Intervertebral joints of the birds neck to identify the mechanical joint representing Intervertebral linkage. This link was described in the literature as a joint allowing two or three rotations and no translation. These features correspond to the rotule a doigt (RAD) joint, a ball and socket joint with a pin. We compared the RAD joint to the postaxial Intervertebral joints of the avian neck and found it a suitable model to determine the geometrical features involved in the joint mobility. The difference in the angles of virtual axes linking the geometrical center of the centrum to the zygapophysis surfaces determines the mean dorsoventral flexion of the joint. It also helps to limit longitudinal rotation. The orientation of the zygapophysis surfaces determines the range of motion in both dorsoventral and lateral flexion. The overall system prevents dislocation. The model was validated on 13 joints of a vulture neck and 11 joints of a swallow neck and on one joint (C6-C7) in each of three mammal species: the wolf (Canis lupus), mole (Talpa europaea), and human (Homo sapiens). The RAD mechanical joint was found in all vertebral Articulations. This validation of the model on different species shows that the RAD Intervertebral joint model makes it possible to extract the parameters that guide and limit the mobility of the cervical spine from the complex shape of the vertebrae and to compare them in interspecific studies.
