The unbearable uncertainty of panarthropod relationships

Ruolin Wu*, Davide Pisani, Philip C J Donoghue

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

7 Citations (Scopus)
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Panarthropoda, the clade comprising the phyla Onychophora, Tardigrada and Euarthropoda, encompasses the largest majority of animal biodiversity. The relationships among the phyla are contested and resolution is key to understanding the evolutionary assembly of the arthropod bodyplans. Molecular phylogenetic analyses generally support monophyly of Onychophora and Euarthropoda to the exclusion of Tardigrada (Lobopodia hypothesis), which is also supported by some analyses of morphological data. However, analyses of morphological data have also been interpreted to support monophyly of Tardigrada and Euarthropoda to the exclusion of Onychophora (Tactopoda hypothesis). Support has also been found for a clade of Onychophora and Tardigrada that excludes Euarthropoda (Protarthropoda hypothesis). Here we show, using a diversity of phylogenetic inference methods, that morphological datasets cannot discriminate statistically between the Lobopodia, Tactopoda and Protarthropoda hypotheses. Since the relationships among the living clades of panarthropod phyla cannot be discriminated based on morphological data, we call into question the accuracy of morphology-based phylogenies of Panarthropoda that include fossil species and the evolutionary hypotheses based upon them.
Original languageEnglish
Article number20220497
Pages (from-to)20220497
Number of pages17
JournalBiology Letters
Issue number1
Publication statusPublished - 11 Jan 2023

Bibliographical note

Funding Information:
R.W. was supported by the scholarship from the Chinese Scholarship Council. D.P. and P.C.J.D. were funded by Natural Environment Research Council (NERC) grant (NE/P013678/1), part of the Biosphere Evolution, Transitions and Resilience (BETR) programme, which is co-funded by the Natural Science Foundation of China (NSFC); the John Templeton Foundation (grant 62220; the opinions expressed in this publication are those of the author(s) and do not necessarily reflect the views of the John Templeton Foundation); the Gordon and Betty Moore Foundation (grant GBMF9741). P.C.J.D. was also funded by the Leverhulme Trust (RF-2022-167) and the Biotechnology and Biological Sciences Research Council (BB/T012773/1). Acknowledgements

Publisher Copyright:
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