Osodobenus eodon

Osodobenus eodon is the only recognised species of Osodobenus, an extinct walrus from the Miocene to Pliocene of California, and it may have been the first tusked walrus. It is known from three specimens, an adult male, an adult female and a juvenile, whose skulls and some postcranial bones were collected from the Capistrano Formation in Orange County. Biewer and colleagues described it in 2020. Only males had large tusks, so tusks were sexually dimorphic in this species, and its palate and enlarged nerve openings suggest that it was a suction feeder, perhaps feeding on the sea floor as the modern walrus does. The species name eodon means dawn tooth or dawn tusk.