Abstract

Today’s mysticetes filter-feed using baleen, a novel integumentary structure with no apparent homolog in any living mammal. The origins of filter-feeding and baleen can be informed by the fossil record, including rare instances of soft tissue preservation of baleen and also by potential osteological correlates of baleen. Lateral palatal foramina on the roof of the mouth have been proposed as potential osteological correlates of baleen and their presence in some tooth-bearing stem mysticetes has led to the hypothesis that these early mysticetes possessed both teeth and incipient baleen. Here, we test this hypothesis by examining lateral palatal foramina in both filter-feeding and non-filter-feeding cetaceans, including crown and stem odontocetes and in stem cetaceans (or archaeocetes). We also confirm the presence of lateral palatal foramina in 61 species of terrestrial artiodactyls. CT scanning demonstrates consistent internal morphology across all observed taxa, suggesting that the lateral palatal foramina observed in extant mysticetes are homologous to those of terrestrial artiodactyls. The presence of lateral palatal foramina in terrestrial artiodactyls and non-filter-feeding whales (odontocetes and archaeocetes) suggests that these structures are not unique predictors for the presence of baleen in fossil whales; instead, these structures are more probably associated with gingiva or other oral tissue.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.