The Rice's Whale: A New Species of Whale Discovered In 2021

Pseudorca crassidens | DORIS

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Phylogenetic analysis suggests fully aquatic mammals are unlikely to evolve back into terrestrial creatures

A trio of biologists and environmental scientists, two with the University of Fribourg and the third with the Swiss Institute of Bioinformatics, has found that fully aquatic mammals, such as whales and porpoises, are very unlikely to evolve back into land animals. In their study, reported in Proceedings of the Royal Society B, B. M. Farina, S. Faurby and D. Silvestro conducted phylogenetic analyses of more than 5,000 mammalian species.

Osteological correlates of evolutionary transitions in cetacean feeding and related oropharyngeal functions

Teeth are often the first structures that anatomists and paleontologists examine to understand the ecology and morphology of feeding, both because teeth are highly specialized structures that provide precise information, and because they are among the best and most commonly preserved fossils. Unfortunately, many fragmentary fossil and recent specimens lack teeth, and some come from edentulous individuals and taxa, as in mysticete (baleen) whales. In our broad comparative review, we survey non-dental osteological features that, due to size, shape, arrangement, and surface features reflecting muscle attachments, provide useful clues to general or specific aspects of prey capture, intraoral transport, processing, or swallowing. We focus on hyoid, palatal, and pterygoid bones, mandibular symphyses and processes such as the coronoid, and the temporal fossa and zygomatic arch, as well as adjacent cranial bones relating to oral and pharyngeal anatomy. These bones relate to muscles of five general locations especially indicative of feeding: mandibular, hyoid, tongue, pharyngeal, and facial regions. Together these bones and muscles affect feeding and related activities including suckling and breathing. We discuss osteological correlates that provide special relevance to key transitions in cetacean evolutionary history, such as the shift from predominantly terrestrial to aquatic feeding, the shift from typical mammalian mastication to swallowing prey entirely or nearly whole, and th...