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New Extinct Walrus-like Species Discovered in North Atlantic
A collaborative research effort led by Dr. Mathieu Boisville from the University of Tsukuba in Japan has resulted in the identification of a new species within the extinct genus Ontocetus. This species, named Ontocetus posti, has been discovered in Lower Pleistocene deposits from the North Atlantic region. Interestingly, the anatomical traits of this species show notable similarities to the modern walrus (Odobenus rosmarus), marking a significant example of convergent evolution. The findings are published in the journal PeerJ.
The fossils of Ontocetus posti were unearthed in locations including Norwich, United Kingdom, and Antwerp, Belgium. Initially misidentified as belonging to another species, Ontocetus emmonsi, a thorough examination of the mandibles exposed a distinct set of features that warranted classification as a new species.
Key anatomical characteristics of Ontocetus posti include the presence of four post-canine teeth, a prominently larger lower canine, and a short, fused mandibular symphysis. These adaptations imply that Ontocetus posti employed suction-feeding techniques, akin to those utilized by contemporary walruses.
Tracing back to their origins in the North Pacific Ocean, the Ontocetus genus dispersed into the Atlantic during the Mio-Pliocene transition, with the Central American Seaway likely facilitating this migration prior to the eventual closure of the Isthmus of Panama.
The global climate shift that began during the Late Pliocene had significant repercussions for marine species, culminating in the extinction of Ontocetus posti in the Early Pleistocene, while paving the way for the emergence and eventual dominance of the cold-adapted Odobenus rosmarus.
This discovery enhances our understanding of walrus evolution and reflects how changes in environmental conditions can influence the adaptation and survival strategies of marine mammals. The similar feeding adaptations between Ontocetus posti and today’s walrus underscore the complexities of evolutionary processes through different geological periods and habitats.
More information:
Boisville M, Chatar N, Kohno N. New species of Ontocetus (Pinnipedia: Odobenidae) from the Lower Pleistocene of the North Atlantic shows similar feeding adaptation independent to the extant walrus (Odobenus rosmarus) PeerJ (2024). DOI: 10.7717/peerj.17666
Journal information:
Citation:
New species of extinct walrus-like mammal discovered in the North Atlantic (2024, August 13) retrieved 13 August 2024 from here.
Source
phys.org