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The Cambrian cirratuliform Iotuba denotes an early annelid radiation
The principal animal lineages (phyla) diverged in the Cambrian, but most diversity at lower taxonomic ranks arose more gradually over the subsequent 500 Myr. Annelid worms seem to exemplify this pattern, based on molecular analyses and the fossil record: Cambrian Burgess Shale-type deposits host a s...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Royal Society
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9890102/ https://www.ncbi.nlm.nih.gov/pubmed/36722078 http://dx.doi.org/10.1098/rspb.2022.2014 |
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author | Zhang, ZhiFei Smith, Martin R. Ren, XinYi |
author_facet | Zhang, ZhiFei Smith, Martin R. Ren, XinYi |
author_sort | Zhang, ZhiFei |
collection | PubMed |
description | The principal animal lineages (phyla) diverged in the Cambrian, but most diversity at lower taxonomic ranks arose more gradually over the subsequent 500 Myr. Annelid worms seem to exemplify this pattern, based on molecular analyses and the fossil record: Cambrian Burgess Shale-type deposits host a single, early-diverging crown-group annelid alongside a morphologically and taxonomically conservative stem group; the polychaete sub-classes diverge in the Ordovician; and many orders and families are first documented in Carboniferous Lagerstätten. Fifteen new fossils of the ‘phoronid’ Iotuba (=Eophoronis) chengjiangensis from the early Cambrian Chengjiang Lagerstätte challenge this picture. A chaetal cephalic cage surrounds a retractile head with branchial plates, affiliating Iotuba with the derived polychaete families ‘Flabelligeridae’ and Acrocirridae. Unless this similarity represents profound convergent evolution, this relationship would pull back the origin of the nested crown groups of Cirratuliformia, Sedentaria and Pleistoannelida by tens of millions of years—indicating a dramatic unseen origin of modern annelid diversity in the heat of the Cambrian ‘explosion’. |
format | Online Article Text |
id | pubmed-9890102 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | The Royal Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-98901022023-02-03 The Cambrian cirratuliform Iotuba denotes an early annelid radiation Zhang, ZhiFei Smith, Martin R. Ren, XinYi Proc Biol Sci Palaeobiology The principal animal lineages (phyla) diverged in the Cambrian, but most diversity at lower taxonomic ranks arose more gradually over the subsequent 500 Myr. Annelid worms seem to exemplify this pattern, based on molecular analyses and the fossil record: Cambrian Burgess Shale-type deposits host a single, early-diverging crown-group annelid alongside a morphologically and taxonomically conservative stem group; the polychaete sub-classes diverge in the Ordovician; and many orders and families are first documented in Carboniferous Lagerstätten. Fifteen new fossils of the ‘phoronid’ Iotuba (=Eophoronis) chengjiangensis from the early Cambrian Chengjiang Lagerstätte challenge this picture. A chaetal cephalic cage surrounds a retractile head with branchial plates, affiliating Iotuba with the derived polychaete families ‘Flabelligeridae’ and Acrocirridae. Unless this similarity represents profound convergent evolution, this relationship would pull back the origin of the nested crown groups of Cirratuliformia, Sedentaria and Pleistoannelida by tens of millions of years—indicating a dramatic unseen origin of modern annelid diversity in the heat of the Cambrian ‘explosion’. The Royal Society 2023-02-08 2023-02-01 /pmc/articles/PMC9890102/ /pubmed/36722078 http://dx.doi.org/10.1098/rspb.2022.2014 Text en © 2023 The Authors. https://creativecommons.org/licenses/by/4.0/Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, provided the original author and source are credited. |
spellingShingle | Palaeobiology Zhang, ZhiFei Smith, Martin R. Ren, XinYi The Cambrian cirratuliform Iotuba denotes an early annelid radiation |
title | The Cambrian cirratuliform Iotuba denotes an early annelid radiation |
title_full | The Cambrian cirratuliform Iotuba denotes an early annelid radiation |
title_fullStr | The Cambrian cirratuliform Iotuba denotes an early annelid radiation |
title_full_unstemmed | The Cambrian cirratuliform Iotuba denotes an early annelid radiation |
title_short | The Cambrian cirratuliform Iotuba denotes an early annelid radiation |
title_sort | cambrian cirratuliform iotuba denotes an early annelid radiation |
topic | Palaeobiology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9890102/ https://www.ncbi.nlm.nih.gov/pubmed/36722078 http://dx.doi.org/10.1098/rspb.2022.2014 |
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