The cranial morphology of Tanystropheus hydroides (Tanystropheidae, Archosauromorpha) as revealed by synchrotron microtomography
The postcranial morphology of the extremely long-necked Tanystropheus hydroides is well-known, but observations of skull morphology were previously limited due to compression of the known specimens. Here we provide a detailed description of the skull of PIMUZ T 2790, including a partial endocast and...
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doaj-9c7b0e30b9554b54860653e1858ceafe2020-11-25T04:09:12ZengPeerJ Inc.PeerJ2167-83592020-11-018e1029910.7717/peerj.10299The cranial morphology of Tanystropheus hydroides (Tanystropheidae, Archosauromorpha) as revealed by synchrotron microtomographyStephan N.F. Spiekman0James M. Neenan1Nicholas C. Fraser2Vincent Fernandez3Olivier Rieppel4Stefania Nosotti5Torsten M. Scheyer6University of Zurich, Palaeontological Institute and Museum, Zurich, SwitzerlandOxford University Museum of Natural History, Oxford, UKNational Museums Scotland, Edinburgh, UKEuropean Synchrotron Radiation Facility, Grenoble, FranceField Museum of Natural History, Chicago, IL, USAMuseo Civico di Storia Naturale di Milano, Milan, ItalyUniversity of Zurich, Palaeontological Institute and Museum, Zurich, SwitzerlandThe postcranial morphology of the extremely long-necked Tanystropheus hydroides is well-known, but observations of skull morphology were previously limited due to compression of the known specimens. Here we provide a detailed description of the skull of PIMUZ T 2790, including a partial endocast and endosseous labyrinth, based on synchrotron microtomographic data, and compare its morphology to that of other early Archosauromorpha. In many features, such as the wide and flattened snout and the configuration of the temporal and palatal regions, Tanystropheus hydroides differs strongly from other early archosauromorphs. The braincase possesses a combination of derived archosaur traits, such as the presence of a laterosphenoid and the ossification of the lateral wall of the braincase, but also differs from archosauriforms in the morphology of the ventral ramus of the opisthotic, the horizontal orientation of the parabasisphenoid, and the absence of a clearly defined crista prootica. Tanystropheus hydroides was a ram-feeder that likely caught its prey through a laterally directed snapping bite. Although the cranial morphology of other archosauromorph lineages is relatively well-represented, the skulls of most tanystropheid taxa remain poorly understood due to compressed and often fragmentary specimens. The recent descriptions of the skulls of Macrocnemus bassanii and now Tanystropheus hydroides reveal a large cranial disparity in the clade, reflecting wide ecological diversity, and highlighting the importance of non-archosauriform Archosauromorpha to both terrestrial and aquatic ecosystems during the Triassic.https://peerj.com/articles/10299.pdfTanystropheusTanystropheidaeArchosauromorphaTriassicCranial anatomyEndocranial anatomy |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Stephan N.F. Spiekman James M. Neenan Nicholas C. Fraser Vincent Fernandez Olivier Rieppel Stefania Nosotti Torsten M. Scheyer |
spellingShingle |
Stephan N.F. Spiekman James M. Neenan Nicholas C. Fraser Vincent Fernandez Olivier Rieppel Stefania Nosotti Torsten M. Scheyer The cranial morphology of Tanystropheus hydroides (Tanystropheidae, Archosauromorpha) as revealed by synchrotron microtomography PeerJ Tanystropheus Tanystropheidae Archosauromorpha Triassic Cranial anatomy Endocranial anatomy |
author_facet |
Stephan N.F. Spiekman James M. Neenan Nicholas C. Fraser Vincent Fernandez Olivier Rieppel Stefania Nosotti Torsten M. Scheyer |
author_sort |
Stephan N.F. Spiekman |
title |
The cranial morphology of Tanystropheus hydroides (Tanystropheidae, Archosauromorpha) as revealed by synchrotron microtomography |
title_short |
The cranial morphology of Tanystropheus hydroides (Tanystropheidae, Archosauromorpha) as revealed by synchrotron microtomography |
title_full |
The cranial morphology of Tanystropheus hydroides (Tanystropheidae, Archosauromorpha) as revealed by synchrotron microtomography |
title_fullStr |
The cranial morphology of Tanystropheus hydroides (Tanystropheidae, Archosauromorpha) as revealed by synchrotron microtomography |
title_full_unstemmed |
The cranial morphology of Tanystropheus hydroides (Tanystropheidae, Archosauromorpha) as revealed by synchrotron microtomography |
title_sort |
cranial morphology of tanystropheus hydroides (tanystropheidae, archosauromorpha) as revealed by synchrotron microtomography |
publisher |
PeerJ Inc. |
series |
PeerJ |
issn |
2167-8359 |
publishDate |
2020-11-01 |
description |
The postcranial morphology of the extremely long-necked Tanystropheus hydroides is well-known, but observations of skull morphology were previously limited due to compression of the known specimens. Here we provide a detailed description of the skull of PIMUZ T 2790, including a partial endocast and endosseous labyrinth, based on synchrotron microtomographic data, and compare its morphology to that of other early Archosauromorpha. In many features, such as the wide and flattened snout and the configuration of the temporal and palatal regions, Tanystropheus hydroides differs strongly from other early archosauromorphs. The braincase possesses a combination of derived archosaur traits, such as the presence of a laterosphenoid and the ossification of the lateral wall of the braincase, but also differs from archosauriforms in the morphology of the ventral ramus of the opisthotic, the horizontal orientation of the parabasisphenoid, and the absence of a clearly defined crista prootica. Tanystropheus hydroides was a ram-feeder that likely caught its prey through a laterally directed snapping bite. Although the cranial morphology of other archosauromorph lineages is relatively well-represented, the skulls of most tanystropheid taxa remain poorly understood due to compressed and often fragmentary specimens. The recent descriptions of the skulls of Macrocnemus bassanii and now Tanystropheus hydroides reveal a large cranial disparity in the clade, reflecting wide ecological diversity, and highlighting the importance of non-archosauriform Archosauromorpha to both terrestrial and aquatic ecosystems during the Triassic. |
topic |
Tanystropheus Tanystropheidae Archosauromorpha Triassic Cranial anatomy Endocranial anatomy |
url |
https://peerj.com/articles/10299.pdf |
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