Cargando…
Ordovician opabiniid-like animals and the role of the proboscis in euarthropod head evolution
A crucial step in the evolution of Euarthropoda (chelicerates, myriapods, pancrustaceans) was the transition between fossil groups that possessed frontal appendages innervated by the first segment of the brain (protocerebrum), and living groups with a protocerebral labrum and paired appendages inner...
Autores principales: | , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2022
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9666559/ https://www.ncbi.nlm.nih.gov/pubmed/36379946 http://dx.doi.org/10.1038/s41467-022-34204-w |
_version_ | 1784831540836958208 |
---|---|
author | Pates, Stephen Botting, Joseph P. Muir, Lucy A. Wolfe, Joanna M. |
author_facet | Pates, Stephen Botting, Joseph P. Muir, Lucy A. Wolfe, Joanna M. |
author_sort | Pates, Stephen |
collection | PubMed |
description | A crucial step in the evolution of Euarthropoda (chelicerates, myriapods, pancrustaceans) was the transition between fossil groups that possessed frontal appendages innervated by the first segment of the brain (protocerebrum), and living groups with a protocerebral labrum and paired appendages innervated by the second brain segment (deutocerebrum). Appendage homologies between the groups are controversial. Here we describe two specimens of opabiniid-like euarthropods, each bearing an anterior proboscis (a fused protocerebral appendage), from the Middle Ordovician Castle Bank Biota, Wales, UK. Phylogenetic analyses support a paraphyletic grade of stem-group euarthropods with fused protocerebral appendages and a posterior-facing mouth, as in the iconic Cambrian panarthropod Opabinia. These results suggest that the labrum may have reduced from an already-fused proboscis, rather than a pair of arthropodized appendages. If some shared features between the Castle Bank specimens and radiodonts are considered convergent rather than homologous, phylogenetic analyses retrieve them as opabiniids, substantially extending the geographic and temporal range of Opabiniidae. |
format | Online Article Text |
id | pubmed-9666559 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-96665592022-11-17 Ordovician opabiniid-like animals and the role of the proboscis in euarthropod head evolution Pates, Stephen Botting, Joseph P. Muir, Lucy A. Wolfe, Joanna M. Nat Commun Article A crucial step in the evolution of Euarthropoda (chelicerates, myriapods, pancrustaceans) was the transition between fossil groups that possessed frontal appendages innervated by the first segment of the brain (protocerebrum), and living groups with a protocerebral labrum and paired appendages innervated by the second brain segment (deutocerebrum). Appendage homologies between the groups are controversial. Here we describe two specimens of opabiniid-like euarthropods, each bearing an anterior proboscis (a fused protocerebral appendage), from the Middle Ordovician Castle Bank Biota, Wales, UK. Phylogenetic analyses support a paraphyletic grade of stem-group euarthropods with fused protocerebral appendages and a posterior-facing mouth, as in the iconic Cambrian panarthropod Opabinia. These results suggest that the labrum may have reduced from an already-fused proboscis, rather than a pair of arthropodized appendages. If some shared features between the Castle Bank specimens and radiodonts are considered convergent rather than homologous, phylogenetic analyses retrieve them as opabiniids, substantially extending the geographic and temporal range of Opabiniidae. Nature Publishing Group UK 2022-11-15 /pmc/articles/PMC9666559/ /pubmed/36379946 http://dx.doi.org/10.1038/s41467-022-34204-w Text en © The Author(s) 2022 https://creativecommons.org/licenses/by/4.0/Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as 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 images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) . |
spellingShingle | Article Pates, Stephen Botting, Joseph P. Muir, Lucy A. Wolfe, Joanna M. Ordovician opabiniid-like animals and the role of the proboscis in euarthropod head evolution |
title | Ordovician opabiniid-like animals and the role of the proboscis in euarthropod head evolution |
title_full | Ordovician opabiniid-like animals and the role of the proboscis in euarthropod head evolution |
title_fullStr | Ordovician opabiniid-like animals and the role of the proboscis in euarthropod head evolution |
title_full_unstemmed | Ordovician opabiniid-like animals and the role of the proboscis in euarthropod head evolution |
title_short | Ordovician opabiniid-like animals and the role of the proboscis in euarthropod head evolution |
title_sort | ordovician opabiniid-like animals and the role of the proboscis in euarthropod head evolution |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9666559/ https://www.ncbi.nlm.nih.gov/pubmed/36379946 http://dx.doi.org/10.1038/s41467-022-34204-w |
work_keys_str_mv | AT patesstephen ordovicianopabiniidlikeanimalsandtheroleoftheproboscisineuarthropodheadevolution AT bottingjosephp ordovicianopabiniidlikeanimalsandtheroleoftheproboscisineuarthropodheadevolution AT muirlucya ordovicianopabiniidlikeanimalsandtheroleoftheproboscisineuarthropodheadevolution AT wolfejoannam ordovicianopabiniidlikeanimalsandtheroleoftheproboscisineuarthropodheadevolution |