''Pontolis'' is an extinct genus of large

walrus The walrus (''Odobenus rosmarus'') is a large pinniped, flippered marine mammal with a discontinuous distribution about the North Pole in the Arctic Ocean and subarctic seas of the Northern Hemisphere. The walrus is the only living species in ...

. It contained three species, ''P. magnus, P. barroni,'' and ''P. kohnoi''. Like all

pinniped Pinnipeds (pronounced ), commonly known as seals, are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammals. They comprise the extant families Odobenidae (whose only living member is the walru ...

s, ''Pontolis'' was a heavily built amphibious carnivore. ''Pontolis'' lived along the Pacific coast of North America along what is now the western coasts of

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

and

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

between 11.608 and 5.332 million years ago, during the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

and

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58

Description

The skull of ''Pontolis'' is long, surpassing skulls of any other prehistoric pinnipeds and twice as big as the skulls of modern male walruses. This giant species was much larger than modern walrus, though like many other extinct walrus species, its upper canines did not develop into long tusks like those of the modern walrus. ''Pontolis'' reached more than in body length, rivaling the extant

southern elephant seal The southern elephant seal (''Mirounga leonina'') is one of two species of elephant seals. It is the largest member of the clade Pinnipedia and the order Carnivora, as well as the largest extant marine mammal that is not a cetacean. It gets it ...

as the largest pinniped and member of the order

Carnivora Carnivora is a Clade, monophyletic order of Placentalia, placental mammals consisting of the most recent common ancestor of all felidae, cat-like and canidae, dog-like animals, and all descendants of that ancestor. Members of this group are f ...

of all time. Weight estimates for ''Pontolis'' range between .Valentin, T. ''Encyclopedia Largest Prehistoric Animals Vol.1 Vertebrates part1 Mammals ch.1 Carnivores - Hyaenidae, Mustelids and Viverrids Encyclopedia Largest prehistoric animals Vol.1 Vertebrates part1 Mammals ch.1 Carnivores -Mesonychids.''

References

Miocene pinnipeds Mammals described in 1905 Fossil taxa described in 1905 Prehistoric pinnipeds of North America Odobenids Prehistoric carnivoran genera {{Paleo-carnivora-stub