by A team of paleontologists has made a remarkable discovery – a new species of an extinct walrus-like mammal called Ontocetus posti.
This species lived about 5.3 million years ago during the Pliocenewas identified from fossilized remains found in Norwich, England and Antwerp, Belgium.
The discovery, published today in the journal PeerJhighlights the fascinating case of convergent evolution, in which Ontocetus posti Despite the considerable time difference and different environmental conditions, they developed adaptations in feeding that are remarkably similar to those of today’s walrus.
The discovery and its significance
The fossils of Ontocetus posti were initially assigned to a different species, Ontocetus emmonsibut a detailed analysis of the mandibles revealed unique features that distinguish it as a new species. These features include the presence of four post-canine teeth, a larger lower canine, and a fused and short mandibular symphysis, suggesting that Ontocetus posti was well adapted to suction feeding – a feeding technique similar to that used by today’s walruses.
According to the lead researcher of the study Mathieu Boisville from the University of Tsukuba in Japan: “This discovery provides new insights into the evolutionary history of walruses and shows how different species have adapted to similar environmental challenges over millions of years.”
The research highlights how environmental changes, such as global cooling in the Late Pliocene, the extinction of Ontocetus posti and the emergence of cold-adapted modern walruses (Odobenus rosmarus).
Understanding the evolution of marine mammals
The discovery of Ontocetus posti offers valuable insights into the evolutionary history of marine mammals, especially walruses. The migration of the genus Ontocetus from the North Pacific to the Atlantic Ocean during the Mio-Pliocene transition highlights the impact of major geological events such as the closure of the Central American Sea Route on the distribution and evolution of marine species. When global cooling began in the 20th century, Late PlioceneSpecies such as Ontocetus posti were unable to adapt to the changing conditions, which led to their extinction and the emergence of species better adapted to cold environments.
This discovery also sheds light on the broader patterns of Evolution of marine mammalsin particular the role of convergent evolution in the development of similar adaptations between different species. The fact that Ontocetus posti The evolution of dietary adaptations similar to those of modern walruses suggests that similar ecological pressures can lead to the evolution of comparable traits, even in species separated by millions of years.
The future of paleontological walrus research
The team behind this discovery hopes to discover more fossils related to Ontocetus posti to better understand the species’ adaptations and the environmental changes that have influenced its evolution. The researchers also want to explore the broader implications of these findings for the study of Evolution of marine mammalsin particular to understand how past climate changes have influenced the evolution of present-day species.
Dr. Boisville and his colleagues believe that this discovery underscores the importance of conservation efforts for modern walruses, which currently face significant challenges due to human activities and global warming. “The modern walrus is greatly affected by human activities, whether through hunting or global warming, which affect its habitat and therefore its prey,” noted Boisville. “We hope that this discovery can strengthen the idea behind protecting these beautiful but endangered animals.”
