Pontolis magnus

Pontolis magnus was an exceptionally large prehistoric pinniped and was more massive than most living seals and sea lions. Fossil material suggests a heavily built animal related to walruses, although estimates are uncertain because no complete skeleton is known.

The species was originally described from fossil remains found in Oregon. Those remains came from marine deposits associated with the northeastern Pacific during the Miocene.

It belonged to Odobenidae, the walrus family, but it did not necessarily resemble the modern tusked walrus Odobenus rosmarus in every detail. Walrus relatives developed several different skull, tooth, and feeding adaptations during the Miocene.

Its exact diet cannot be reconstructed with certainty from the incomplete fossils. Unlike the specialized suction-feeding modern walrus, some extinct odobenids retained dentitions suited to catching fish or other marine prey.