Cargando…
A revised cranial description of Massospondylus carinatus Owen (Dinosauria: Sauropodomorpha) based on computed tomographic scans and a review of cranial characters for basal Sauropodomorpha
Massospondylus carinatus is a basal sauropodomorph dinosaur from the early Jurassic Elliot Formation of South Africa. It is one of the best-represented fossil dinosaur taxa, known from hundreds of specimens including at least 13 complete or nearly complete skulls. Surprisingly, the internal cranial...
Autores principales: | , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
PeerJ Inc.
2018
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5768178/ https://www.ncbi.nlm.nih.gov/pubmed/29340238 http://dx.doi.org/10.7717/peerj.4224 |
_version_ | 1783292655976841216 |
---|---|
author | Chapelle, Kimberley E.J. Choiniere, Jonah N. |
author_facet | Chapelle, Kimberley E.J. Choiniere, Jonah N. |
author_sort | Chapelle, Kimberley E.J. |
collection | PubMed |
description | Massospondylus carinatus is a basal sauropodomorph dinosaur from the early Jurassic Elliot Formation of South Africa. It is one of the best-represented fossil dinosaur taxa, known from hundreds of specimens including at least 13 complete or nearly complete skulls. Surprisingly, the internal cranial anatomy of M. carinatus has never been described using computed tomography (CT) methods. Using CT scans and 3D digital representations, we digitally reconstruct the bones of the facial skeleton, braincase, and palate of a complete, undistorted cranium of M. carinatus (BP/1/5241). We describe the anatomical features of the cranial bones, and compare them to other closely related sauropodomorph taxa such as Plateosaurus erlenbergiensis, Lufengosaurus huenei, Sarahsaurus aurifontanalis and Efraasia minor. We identify a suite of character states of the skull and braincase for M. carinatus that sets it apart from other taxa, but these remain tentative due to the lack of comparative sauropodomorph braincase descriptions in the literature. Furthermore, we hypothesize 27 new cranial characters useful for determining relationships in non-sauropodan Sauropodomorpha, delete five pre-existing characters and revise the scores of several existing cranial characters to make more explicit homology statements. All the characters that we hypothesized or revised are illustrated. Using parsimony as an optimality criterion, we then test the relationships of M. carinatus (using BP/1/5241 as a specimen-level exemplar) in our revised phylogenetic data matrix. |
format | Online Article Text |
id | pubmed-5768178 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | PeerJ Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-57681782018-01-16 A revised cranial description of Massospondylus carinatus Owen (Dinosauria: Sauropodomorpha) based on computed tomographic scans and a review of cranial characters for basal Sauropodomorpha Chapelle, Kimberley E.J. Choiniere, Jonah N. PeerJ Evolutionary Studies Massospondylus carinatus is a basal sauropodomorph dinosaur from the early Jurassic Elliot Formation of South Africa. It is one of the best-represented fossil dinosaur taxa, known from hundreds of specimens including at least 13 complete or nearly complete skulls. Surprisingly, the internal cranial anatomy of M. carinatus has never been described using computed tomography (CT) methods. Using CT scans and 3D digital representations, we digitally reconstruct the bones of the facial skeleton, braincase, and palate of a complete, undistorted cranium of M. carinatus (BP/1/5241). We describe the anatomical features of the cranial bones, and compare them to other closely related sauropodomorph taxa such as Plateosaurus erlenbergiensis, Lufengosaurus huenei, Sarahsaurus aurifontanalis and Efraasia minor. We identify a suite of character states of the skull and braincase for M. carinatus that sets it apart from other taxa, but these remain tentative due to the lack of comparative sauropodomorph braincase descriptions in the literature. Furthermore, we hypothesize 27 new cranial characters useful for determining relationships in non-sauropodan Sauropodomorpha, delete five pre-existing characters and revise the scores of several existing cranial characters to make more explicit homology statements. All the characters that we hypothesized or revised are illustrated. Using parsimony as an optimality criterion, we then test the relationships of M. carinatus (using BP/1/5241 as a specimen-level exemplar) in our revised phylogenetic data matrix. PeerJ Inc. 2018-01-12 /pmc/articles/PMC5768178/ /pubmed/29340238 http://dx.doi.org/10.7717/peerj.4224 Text en © 2018 Chapelle and Choiniere http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ) and either DOI or URL of the article must be cited. |
spellingShingle | Evolutionary Studies Chapelle, Kimberley E.J. Choiniere, Jonah N. A revised cranial description of Massospondylus carinatus Owen (Dinosauria: Sauropodomorpha) based on computed tomographic scans and a review of cranial characters for basal Sauropodomorpha |
title | A revised cranial description of Massospondylus carinatus Owen (Dinosauria: Sauropodomorpha) based on computed tomographic scans and a review of cranial characters for basal Sauropodomorpha |
title_full | A revised cranial description of Massospondylus carinatus Owen (Dinosauria: Sauropodomorpha) based on computed tomographic scans and a review of cranial characters for basal Sauropodomorpha |
title_fullStr | A revised cranial description of Massospondylus carinatus Owen (Dinosauria: Sauropodomorpha) based on computed tomographic scans and a review of cranial characters for basal Sauropodomorpha |
title_full_unstemmed | A revised cranial description of Massospondylus carinatus Owen (Dinosauria: Sauropodomorpha) based on computed tomographic scans and a review of cranial characters for basal Sauropodomorpha |
title_short | A revised cranial description of Massospondylus carinatus Owen (Dinosauria: Sauropodomorpha) based on computed tomographic scans and a review of cranial characters for basal Sauropodomorpha |
title_sort | revised cranial description of massospondylus carinatus owen (dinosauria: sauropodomorpha) based on computed tomographic scans and a review of cranial characters for basal sauropodomorpha |
topic | Evolutionary Studies |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5768178/ https://www.ncbi.nlm.nih.gov/pubmed/29340238 http://dx.doi.org/10.7717/peerj.4224 |
work_keys_str_mv | AT chapellekimberleyej arevisedcranialdescriptionofmassospondyluscarinatusowendinosauriasauropodomorphabasedoncomputedtomographicscansandareviewofcranialcharactersforbasalsauropodomorpha AT choinierejonahn arevisedcranialdescriptionofmassospondyluscarinatusowendinosauriasauropodomorphabasedoncomputedtomographicscansandareviewofcranialcharactersforbasalsauropodomorpha AT chapellekimberleyej revisedcranialdescriptionofmassospondyluscarinatusowendinosauriasauropodomorphabasedoncomputedtomographicscansandareviewofcranialcharactersforbasalsauropodomorpha AT choinierejonahn revisedcranialdescriptionofmassospondyluscarinatusowendinosauriasauropodomorphabasedoncomputedtomographicscansandareviewofcranialcharactersforbasalsauropodomorpha |