Initially, the fossils were identified as belonging to another extinct walrus species, Ontocetus emmonsi. However, a detailed inspection of the jawbones revealed that they belonged to a new species.

Upper Township resident Joseph Camburn, an amateur fossil hunter, bought several mastadon teeth from a commercial fisherman. He also has a partial walrus skull pulled from the bottom of the ...

I Am the Walrus but This Fossil Was Not. ... Like its close kin, Ontocetus posti had a complement of teeth, including lower incisors and a large lower canine.

Now, there is only one main species with two subspecies–the Atlantic Walrus and Pacific Walrus. The fossilized remains of Ontocetus posti were discovered in Norwich, England and Antwerp, Belgium .