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Unappreciated diversification of stem archosaurs during the Middle Triassic predated the dominance of dinosaurs
BACKGROUND: Archosauromorpha originated in the middle–late Permian, radiated during the Triassic, and gave rise to the crown group Archosauria, a highly successful clade of reptiles in terrestrial ecosystems over the last 250 million years. However, scientific attention has mainly focused on the div...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5024528/ https://www.ncbi.nlm.nih.gov/pubmed/27628503 http://dx.doi.org/10.1186/s12862-016-0761-6 |
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author | Foth, Christian Ezcurra, Martín D. Sookias, Roland B. Brusatte, Stephen L. Butler, Richard J. |
author_facet | Foth, Christian Ezcurra, Martín D. Sookias, Roland B. Brusatte, Stephen L. Butler, Richard J. |
author_sort | Foth, Christian |
collection | PubMed |
description | BACKGROUND: Archosauromorpha originated in the middle–late Permian, radiated during the Triassic, and gave rise to the crown group Archosauria, a highly successful clade of reptiles in terrestrial ecosystems over the last 250 million years. However, scientific attention has mainly focused on the diversification of archosaurs, while their stem lineage (i.e. non-archosaurian archosauromorphs) has often been overlooked in discussions of the evolutionary success of Archosauria. Here, we analyse the cranial disparity of late Permian to Early Jurassic archosauromorphs and make comparisons between non-archosaurian archosauromorphs and archosaurs (including Pseudosuchia and Ornithodira) on the basis of two-dimensional geometric morphometrics. RESULTS: Our analysis recovers previously unappreciated high morphological disparity for non-archosaurian archosauromorphs, especially during the Middle Triassic, which abruptly declined during the early Late Triassic (Carnian). By contrast, cranial disparity of archosaurs increased from the Middle Triassic into the Late Triassic, declined during the end-Triassic extinction, but re-expanded towards the end of the Early Jurassic. CONCLUSIONS: Our study indicates that non-archosaurian archosauromorphs were highly diverse components of terrestrial ecosystems prior to the major radiation of archosaurs, including dinosaurs, while disparity patterns of the Ladinian and Carnian indicate a gradual faunal replacement of stem archosaurs by the crown group, including a short interval of partial overlap in morphospace during the Ladinian. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12862-016-0761-6) contains supplementary material, which is available to authorized users. |
format | Online Article Text |
id | pubmed-5024528 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-50245282016-09-20 Unappreciated diversification of stem archosaurs during the Middle Triassic predated the dominance of dinosaurs Foth, Christian Ezcurra, Martín D. Sookias, Roland B. Brusatte, Stephen L. Butler, Richard J. BMC Evol Biol Research Article BACKGROUND: Archosauromorpha originated in the middle–late Permian, radiated during the Triassic, and gave rise to the crown group Archosauria, a highly successful clade of reptiles in terrestrial ecosystems over the last 250 million years. However, scientific attention has mainly focused on the diversification of archosaurs, while their stem lineage (i.e. non-archosaurian archosauromorphs) has often been overlooked in discussions of the evolutionary success of Archosauria. Here, we analyse the cranial disparity of late Permian to Early Jurassic archosauromorphs and make comparisons between non-archosaurian archosauromorphs and archosaurs (including Pseudosuchia and Ornithodira) on the basis of two-dimensional geometric morphometrics. RESULTS: Our analysis recovers previously unappreciated high morphological disparity for non-archosaurian archosauromorphs, especially during the Middle Triassic, which abruptly declined during the early Late Triassic (Carnian). By contrast, cranial disparity of archosaurs increased from the Middle Triassic into the Late Triassic, declined during the end-Triassic extinction, but re-expanded towards the end of the Early Jurassic. CONCLUSIONS: Our study indicates that non-archosaurian archosauromorphs were highly diverse components of terrestrial ecosystems prior to the major radiation of archosaurs, including dinosaurs, while disparity patterns of the Ladinian and Carnian indicate a gradual faunal replacement of stem archosaurs by the crown group, including a short interval of partial overlap in morphospace during the Ladinian. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12862-016-0761-6) contains supplementary material, which is available to authorized users. BioMed Central 2016-09-15 /pmc/articles/PMC5024528/ /pubmed/27628503 http://dx.doi.org/10.1186/s12862-016-0761-6 Text en © The Author(s). 2016 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. |
spellingShingle | Research Article Foth, Christian Ezcurra, Martín D. Sookias, Roland B. Brusatte, Stephen L. Butler, Richard J. Unappreciated diversification of stem archosaurs during the Middle Triassic predated the dominance of dinosaurs |
title | Unappreciated diversification of stem archosaurs during the Middle Triassic predated the dominance of dinosaurs |
title_full | Unappreciated diversification of stem archosaurs during the Middle Triassic predated the dominance of dinosaurs |
title_fullStr | Unappreciated diversification of stem archosaurs during the Middle Triassic predated the dominance of dinosaurs |
title_full_unstemmed | Unappreciated diversification of stem archosaurs during the Middle Triassic predated the dominance of dinosaurs |
title_short | Unappreciated diversification of stem archosaurs during the Middle Triassic predated the dominance of dinosaurs |
title_sort | unappreciated diversification of stem archosaurs during the middle triassic predated the dominance of dinosaurs |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5024528/ https://www.ncbi.nlm.nih.gov/pubmed/27628503 http://dx.doi.org/10.1186/s12862-016-0761-6 |
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