Palaeontologists from Japan, Belgium, and the United States have identified a new species of the extinct genus. Ontocetus Nearly complete fossil jaws from the Early Pleistocene in Britain and the Netherlands, and a fragmentary jaw from the Late Pliocene in Belgium, have been found. Ontocetus posti The new species shows striking similarities in its adaptations to modern diets. Walrus (Odobenus rosmarus) It highlights an intriguing case of convergent evolution.
“Walruses are one of the most iconic mammals of the Arctic, distinguished from all other seals (pinnipeds) by their large bodies and conspicuous tusks,” said paleontologist Matthieu Boisville of the University of Tsukuba and his colleagues.
“Walruses are one of the largest carnivorous animals, with males of this species weighing up to 2.5 tonnes and reaching an average length of 3 meters.”
“They live in the shallow, cold Arctic waters, where males form small harems during the breeding season.”
“Their primary diet is bivalve mollusks such as clams, which they capture using a unique ‘suction feeding’ technique, sucking out the shellfish flesh using their lips, tongue and arched palate as pistons.”
“Extant walruses live mainly in the Arctic, but their extinct relatives once lived in temperate and subtropical latitudes, mainly in the eastern North Pacific Ocean during the Miocene. They come in a wide range of shapes and sizes, from small, sea-lion-like ‘adults’ to the bizarre and unique two-tusked walrus.”
Ontocetus posti It lived in what is now Europe between 3.7 and 1.7 million years ago (Late Pliocene to Early Pleistocene).
The remains of this marine animal were initially thought to belong to a different species, Ontocetus emmonsi.
However, detailed analysis of the specimen revealed a unique combination of characteristics that distinguished the creature as a new species.
These features include four posterior canine teeth, large mandibular canines, and a fused and short mandibular symphysis.
These anatomical features are Ontocetus posti They are highly adapted to feeding by sucking cups, somewhat similar to their modern relatives, the walruses.
“Ontocetus and Odobenus They did not coexist in the North Atlantic. Odobenus Appeared almost a million years after extinction Ontocetus” the paleontologist said.
“Described as a temperate to high temperature resistant tusked walrus, Ontocetus They colonized the western North Atlantic during the Early Pliocene and migrated to the North Sea during the Late Pliocene warm period.
“Its prevalence in warm waters is Odobenus.”
“The global climatic cooling during the Early Pleistocene inevitably affected the North Sea’s molluscan fauna and contributed to its isolation from the North Atlantic,” the researchers said.
“External factors related to the specialization of sucker feeding are Ontocetus posti This probably contributed to their extinction about 1.7 million years ago.”
“We hope that more detailed investigations will shed light on past diversity. Ontocetus and Odobenus This revealed the superiority of cold-tolerant plants on a global scale. Odobenus rosmarus As the sole survivor.”
The results of this study are: journal Peer J.
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M. Boisville others2024. A new species Ontocetus The pinniped family Odobenidae, which lived in the Lower Pleistocene of the North Atlantic, is a similar group to modern walruses (Odobenus rosmarus). Peer J 12
Source: www.sci.news
