Extinct walrus-like mammal discovered in Atlantic, offers new insights into marine evolution

Scientists have discovered a previously unknown species of marine mammal, Ontocetus posti, which lived 2.2 million years ago. Led by Dr. Matthew Boisville of the University of Tsukuba, the discovery provides new insights into the evolutionary history of walruses and the impact of environmental change on marine life. Fossil remains found in Norwich, UK, and Antwerp, Belgium, were initially misidentified but later revealed unique features that set Ontocetus postii apart from its relatives.

New insights into evolution

The newly identified Ontocetus postii exhibits several notable features, such as four post-canine teeth, a larger lower canine, and a short, fused mandibular symphysis. These features suggest that it was a suction-feeder, similar to the modern walrus. Dr. Boisville noted that the finding highlights convergent evolution, where different species develop similar traits due to similar environmental stressors.

Migration and adaptation

of Ontocetus posti presence The North Atlantic depicts a fascinating migration story. Ontocetus is believed to have originated in the North Pacific and migrated to the Atlantic via the Central American Seaway, now a closed seaway. As the climate cooled in the late Pliocene and the seaway closed, the environment changed significantly, possibly contributing to the extinction of Ontocetus posti by the early Pleistocene. This extinction paved the way for the modern walrus, Odobenus rosmarus, which now lives in the Arctic.

Importance of discovery

The discovery of Ontocetus posti is crucial to understanding walrus evolution and the impact of past environmental changes on marine mammals. It underscores how species adapt to a changing climate and can provide insight into how current and future climate changes may affect marine life. Such endangered species studies help refine our knowledge of marine mammal evolution and guide conservation efforts for extant species.

Future research directions

The discovery opens new avenues for research on pinnipeds, including seals, sea lions and walruses. Future studies may explore other Pleistocene deposits to uncover more about marine mammal diversity. Each discovery provides clues to marine ecosystems, both past and present, enriching our understanding of the history of life in our oceans.