Research paper

Is Onychodontida (Osteichthyes, Sarcopterygii) monophyletic? Assessing discordant phylogenies with quantitative comparative cladistics 


MARÍA CIUDAD REAL
Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, C/ Catedràtic José Beltrán Martínez, 2, 46980 Paterna, Spain; paleobiologa@gmail.com
Corresponding author

JORGE MONDÉJAR FERNÁNDEZ
Senckenberg Forschungsinstitut und Naturmuseum Frankfurt, Senckenberganlage 25, 60325 Frankfurt am Main, Germany: jorge.mondejar-fernandez@senckenberg.de

Département Origines & Évolution, Muséum national d’Histoire naturelle, 57 rue Cuvier, 75005, Paris, France.

DANIEL VIDAL
Grupo de Biología Evolutiva, Facultad de Ciencias, UNED, Paseo Senda Del Rey, 9, 28040 Madrid, Spain: eoalulavis@gmail.com

HÉCTOR BOTELLA
Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, C/ Catedràtic José Beltrán Martínez, 2, 46980 Paterna, Spain; hector.botella@uv.es


ABSTRACT

Onychodontida (Osteichthyes, Sarcopterygii) was an extinct group of Devonian predatory marine fishes, representing an early branch in sarcopterygian evolution, and currently considered closely related to coelacanths (Actinistia). Due to their limited fossil record, the relationships of onychodonts within sarcopterygians, and whether all taxa traditionally considered as onychodonts form a clade, are still unclear. Here we review the most recent phylogenetic analyses by comparing their data matrices using recent tools and methodology in quantitative comparative cladistics in order to evaluate the source of discrepancies in the different datasets and provide possible practical solutions to test the monophyly of Onychodontida. These discrepancies range from the ambiguous formulation of character statements and character states to the poor preservation of certain fossils, which make interpretation of character states difficult. Understudied but highly complete fossil specimens are also a source of missing data that have an impact in discording tree topologies. In-depth analysis and description of these specimens is needed to improve the resolution of future phylogenetic analyses. Finally, we propose a formal stem-based phylogenetic definition for Onychodontida. 


Key words: Character mapping, Comparative cladistics, Phylogeny, Data matrices, Devonian, Onychodontida, Sarcopterygii, Palaeozoic.

How to cite: Ciudad Real, M., Mondéjar Fernández, J., Vidal, D. & Botella, H. 2022. Is Onychodontida (Osteichthyes, Sarcopterygii) monophyletic? Assessing discordant phylogenies with quantitative comparative cladistics. Spanish Journal of Palaeontology, 37(1), 87-100.

Received 2 December 2021, Accepted 8 April 2022, Published online 17 May 2022

https://doi.org/10.7203/sjp.24256