Saccorhytus is an early ecdysozoan and not the earliest deuterostome

Autor: Yunhuan Liu, Emily Carlisle, Huaqiao Zhang, Ben Yang, Michael Steiner, Tiequan Shao, Baichuan Duan, Federica Marone, Shuhai Xiao, Philip C. J. Donoghue
Rok vydání: 2022
Předmět:
Zdroj: Liu, Y, Carlisle, E M, Zhang, H, Yang, B, Steiner, M, Shao, T, Duan, B, Marone, F, Xiao, S & Donoghue, P C J 2022, ' Saccorhytus is an early ecdysozoan and not the earliest deuterostome ', Nature, vol. 609, no. 7927, pp. 541-546 . https://doi.org/10.1038/s41586-022-05107-z
ISSN: 1476-4687
0028-0836
Popis: The early history of deuterostomes, the group composed of the chordates, echinoderms and hemichordates, is still controversial, not least because of a paucity of stem-representatives to these clades. The early Cambrian microscopic animal Saccorhytus coronarius was interpreted as an early deuterostome on the basis of purported pharyngeal openings, providing evidence for a meiofaunal ancestry and an explanation for the temporal mismatch between palaeontological and molecular clock timescales of animal evolution. Here we report new material of Saccorhytus coronarius, which is reconstructed as a millimetric and ellipsoidal meiobenthic animal with spinose armor and a terminal mouth but no anus. Purported pharyngeal openings in support of the deuterostome hypothesis are shown to be taphonomic artifacts. Phylogenetic analyses indicate that Saccorhytus coronarius belongs to total-group Ecdysozoa, expanding the morphological disparity and ecological diversity of early Cambrian ecdysozoans.
Databáze: OpenAIRE
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