Paleontologists uncover new Ontocetus species with walrus-like feeding adaptations

A groundbreaking discovery by a team of paleontologists led by Dr. Mathieu Boisville from the University of Tsukuba, Japan, has unveiled a new species of extinct cetacean from the Lower Pleistocene era in the North Atlantic.

A team of paleontologists led by Dr. Mathieu Boisville from the University of Tsukuba, Japan, has identified a new species of the extinct genus Ontocetus from Lower Pleistocene deposits in the North Atlantic, Caliber.Az reports, citing foreign media.

The newly named Ontocetus posti shows remarkable similarities in feeding adaptations to the modern walrus (Odobenus rosmarus), offering an intriguing example of convergent evolution. This research is published in the open-access journal PeerJ Life & Environment.

Fossils of Ontocetus posti were found in Norwich, UK, and Antwerp, Belgium. Initially, these remains were believed to belong to the species Ontocetus emmonsi. However, a detailed examination of the mandibles uncovered a distinct set of features, leading to the identification of this new species.

These characteristics include four post-canine teeth, a larger lower canine, and a short, fused mandibular symphysis. These anatomical features indicate that Ontocetus posti was well-adapted for suction feeding, resembling its modern relative, the walrus, in this regard.

The Ontocetus genus, originally from the North Pacific Ocean, migrated to the Atlantic during the Mio-Pliocene transition, likely facilitated by the Central American Seaway, an important oceanic route before the closure of the Isthmus of Panama.

The onset of global cooling in the Late Pliocene had a profound impact on marine life, leading to the extinction of Ontocetus posti in the Early Pleistocene and paving the way for the emergence and dominance of the cold-adapted Odobenus rosmarus.

This discovery provides valuable insights into the evolutionary history of walruses, highlighting how environmental changes have influenced the adaptations and survival of marine mammals. The similarity in feeding adaptations between Ontocetus posti and modern walruses underscores the dynamic nature of evolutionary processes across different periods and environments.