Odobenocetops is an extinct species of toothed whale from the Pliocene epoch of South America. It’s closely related to species like porpoises, narwhal and beluga. Odobenocetops shows an astonishing feeding adaption which can be compared to that of walruses. They probably fed on molluscs, sucking them out of the sea bottom and removed the shells with their powerful tongue. The tusks, on the other hand, probably didn’t play a role in their feeding behaviour and were potentially used by males for social competition.
The genus of Odobenocetops consists of two species that lived in the same period in, what is now, Peru during the Pliocene epoch. O. leptodon was a slightly smaller species but had by far the largest tusks. A fossilized skull of O. leptodon still retained a tusk of 135 cm long and could have been easily 30 cm longer before it lost its tip! The other tusk was way smaller. Besides the tusks, other key differences between O. leptodon and the type species O. peruvianus were the possible presence of a melon on the forehead of O. leptodon. This would mean that it could use echolocation to find its prey.
Muizon, Domning & Parrish, 1999
De Muizon, C. & Domning, D. P. (2002). The anatomy of Odobenocetops (Delphinoidea, Mammalia), the walrus-like dolphin from the Pliocene of Peru and its palaeobiological implications. Zoological Journal of the Linnean Society, 134(4), 423-452.