The bony labyrinth of toothed whales reflects both phylogeny and habitat preferences

• Published in: Scientific Reports
• Main Authors: Costeur, Loïc, Grohé, Camille, Aguirre-Fernández, Gabriel, Ekdale, Eric, Schulz, Georg, Müller, Bert, Mennecart, Bastien
• Other Authors: Naturhistorisches Museum Basel, Laboratoire de paléontologie, évolution, paléoécosystèmes, paléoprimatologie (PALEVOPRIM ), Université de Poitiers-Centre National de la Recherche Scientifique (CNRS), Paleontological Institute and Museum, University of Zurich, San Diego State University (SDSU), University of Basel (Unibas)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: Inner ear; Mammals; Odontocetes; Aquatic habitat; Phylogeny; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SCCO.NEUR]Cognitive science/Neuroscience; [SDU.STU.PG]Sciences of the Universe [physics]/Earth Sciences/Paleontology; Labyrinth; baleen whales; toothed whales
• Online Access: https://hal.archives-ouvertes.fr/hal-03514612; https://doi.org/10.1038/s41598-018-26094-0

International audience The inner ear of toothed whales (odontocetes) is known to have evolved particular shapes related to their abilities to echolocate and move under water. While the origin of these capacities is now more and more examined, thanks to new imaging techniques, little is still known about how informative inner ear shape could be to tackle phylogenetic issues or questions pertaining to the habitat preferences of extinct species. Here we show that the shape of the bony labyrinth of toothed whales provides key information both about phylogeny and habitat preferences (freshwater versus coastal and fully marine habitats). Our investigation of more than 20 species of extinct and modern odontocetes shows that the semi-circular canals are not very informative, in contrast to baleen whales, while the cochlea alone bears a strong signal. Inner ear shape thus provides a novel source of information to distinguish between morphologically convergent lineages (e.g. river dolphins).