Size, not phylogeny, explains the morphology of the endosseous labyrinth in the crown clade Crocodylia
The endosseous labyrinths are associated with several functions, including hearing and spatial orientation. Throughout their evolutionary history, crocodylomorphs have thrived in diverse environments, and the morphology of their endosseous labyrinths has been suggested as a proxy for inferring their lifestyle. However, the relationships between the shape of their endosseous labyrinths and ontogenetic and phylogenetic factors are difficult to interpret and have rarely been investigated in depth previously, particularly in terms of dataset size. Here, we present the most complete dataset to date on the endosseous labyrinths of extant crocodylians, including 111 specimens covering 22 species of different ontogenetic status (from hatchlings to adults). Using 3D geometric morphometrics, we show that allometry constitutes a major contributor of the shape variation of the crocodylian endosseous labyrinths and that the development of this structure is likely linked to the braincase conformation, in all extant genera. We also find a moderate phylogenetic signal, but only without considering the size effect, so it could not be translated into relevant discrete morphological characters. Based on these results, we discuss several remaining problems that prevent the inclusion of fossil forms with highly divergent lifestyles to study how ecological differences shaped the endosseous labyrinths of crocodylomorphs.
Authors
- Romain Amiot (ORCID: https://orcid.org/0000-0003-2779-9652)
- Yohan Pochat‐Cottilloux (ORCID: https://orcid.org/0000-0002-6216-2721)
- Irena Raselli (ORCID: https://orcid.org/0000-0002-8148-3256)
- Lionel Hautier (ORCID: https://orcid.org/0000-0001-8701-5421)
- Joël Lachambre (ORCID: https://orcid.org/0000-0002-0304-7459)
- Jérôme Adrien (ORCID: https://orcid.org/0000-0003-0341-3559)
- Nicolas Rinder
- Jeremy E. Martin (ORCID: https://orcid.org/0000-0001-9159-645X)
- Gwendal Perrichon (ORCID: https://orcid.org/0000-0001-5831-764X)
- Vincent Fernández (ORCID: https://orcid.org/0000-0002-8315-1458)
Institutions
- Université Claude Bernard Lyon 1 (FR)
- Centre National de la Recherche Scientifique (FR)
- Museum of London (GB)
- Natural History Museum (GB)
- University of Fribourg (CH)
- Université de Montpellier (FR)
- Natural History Museum of Geneva (CH)
- European Synchrotron Radiation Facility (FR)
- Institut des Sciences de l'Evolution de Montpellier (FR)
- Matériaux Ingénierie et Science (FR)
- Institut de Biologia Evolutiva (ES)
- Laboratoire de Géologie de Lyon : Terre, Planètes et Environnement (FR)
- Institut de Recherche pour le Développement (FR)
- University of Warsaw (PL)
Publication Details
- Journal
- Journal of Anatomy
- Published
- 2024-12-20
- DOI
- https://doi.org/10.1111/joa.14170
- Citations
- 1
- Primary Topic
- Paleontology and Evolutionary Biology
- Type
- article
- Field-Weighted Citation Impact
- 1.59
Funders
- National Science Foundation
- Field Museum
- University of West London
- Agence Nationale de la Recherche
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- Muséum National d'Histoire Naturelle
- Koninklijk Belgisch Instituut voor Natuurwetenschappen