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Ontogeny of highly variable ceratitid ammonoids from the Anisian (Middle Triassic)

Ammonoids reached their greatest diversity during the Triassic period. In the early Middle Triassic (Anisian) stage, ammonoid diversity was dominated by representatives of the family Ceratitidae. High taxonomic diversity can, however, be decoupled from their morphologic disparity. Due to its high ph...

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Detalles Bibliográficos
Autores principales: Bischof, Eva Alexandra, Schlüter, Nils, Korn, Dieter, Lehmann, Jens
Formato: Online Artículo Texto
Lenguaje:English
Publicado: PeerJ Inc. 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7934684/
https://www.ncbi.nlm.nih.gov/pubmed/33717689
http://dx.doi.org/10.7717/peerj.10931
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author Bischof, Eva Alexandra
Schlüter, Nils
Korn, Dieter
Lehmann, Jens
author_facet Bischof, Eva Alexandra
Schlüter, Nils
Korn, Dieter
Lehmann, Jens
author_sort Bischof, Eva Alexandra
collection PubMed
description Ammonoids reached their greatest diversity during the Triassic period. In the early Middle Triassic (Anisian) stage, ammonoid diversity was dominated by representatives of the family Ceratitidae. High taxonomic diversity can, however, be decoupled from their morphologic disparity. Due to its high phenotypic variability, the high diversity of ceratitids of the Anisian of Nevada was initially assumed to be caused by artificial over-splitting. This study aims to contribute data to settle this issue by applying geometric morphometrics methods, using landmarks and semi-landmarks, in the study of ontogenetic cross-sections of ammonoids for the first time. The results reveal that alterations in ontogenetic trajectories, linked to heterochronic processes, lead to the morphologic diversification of the species studied herein. Our knowledge, based on these ontogenetic changes, challenge the traditional treatment of species using solely adult characters for their distinction. This study furthermore demonstrates that the high diversity of the Anisian ammonoid assemblages of Nevada based on the traditional nomenclatoric approach is regarded to be reasonably accurate.
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spelling pubmed-79346842021-03-11 Ontogeny of highly variable ceratitid ammonoids from the Anisian (Middle Triassic) Bischof, Eva Alexandra Schlüter, Nils Korn, Dieter Lehmann, Jens PeerJ Biodiversity Ammonoids reached their greatest diversity during the Triassic period. In the early Middle Triassic (Anisian) stage, ammonoid diversity was dominated by representatives of the family Ceratitidae. High taxonomic diversity can, however, be decoupled from their morphologic disparity. Due to its high phenotypic variability, the high diversity of ceratitids of the Anisian of Nevada was initially assumed to be caused by artificial over-splitting. This study aims to contribute data to settle this issue by applying geometric morphometrics methods, using landmarks and semi-landmarks, in the study of ontogenetic cross-sections of ammonoids for the first time. The results reveal that alterations in ontogenetic trajectories, linked to heterochronic processes, lead to the morphologic diversification of the species studied herein. Our knowledge, based on these ontogenetic changes, challenge the traditional treatment of species using solely adult characters for their distinction. This study furthermore demonstrates that the high diversity of the Anisian ammonoid assemblages of Nevada based on the traditional nomenclatoric approach is regarded to be reasonably accurate. PeerJ Inc. 2021-03-02 /pmc/articles/PMC7934684/ /pubmed/33717689 http://dx.doi.org/10.7717/peerj.10931 Text en ©2021 Bischof et al. https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (https://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 Biodiversity
Bischof, Eva Alexandra
Schlüter, Nils
Korn, Dieter
Lehmann, Jens
Ontogeny of highly variable ceratitid ammonoids from the Anisian (Middle Triassic)
title Ontogeny of highly variable ceratitid ammonoids from the Anisian (Middle Triassic)
title_full Ontogeny of highly variable ceratitid ammonoids from the Anisian (Middle Triassic)
title_fullStr Ontogeny of highly variable ceratitid ammonoids from the Anisian (Middle Triassic)
title_full_unstemmed Ontogeny of highly variable ceratitid ammonoids from the Anisian (Middle Triassic)
title_short Ontogeny of highly variable ceratitid ammonoids from the Anisian (Middle Triassic)
title_sort ontogeny of highly variable ceratitid ammonoids from the anisian (middle triassic)
topic Biodiversity
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7934684/
https://www.ncbi.nlm.nih.gov/pubmed/33717689
http://dx.doi.org/10.7717/peerj.10931
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