They have distinctive tusks which are used as levers, to move their heavy bodies when on land. Phocids cannot support themselves with their foreflippers on land and they lack external ears. The Pinnipeds are aquatic Carnivorans. They are believed to have split away from the Ursidae lineage around 25 million years ago. Although pinnipeds rely completely upon the sea for food, they give birth to and suckle their young on land or on ice.
Pinnipeds have a carnivorous diet which varies from species to species.
They feed largely on fish and crustaceans but some eat birds and other young seals. Leopard seals, for example, feed extensively on Crabeater seals and Walruses sometimes feed on Ringed seals. Their dentition is modified for grasping prey rather than chewing it. As a result, most prey is swallowed whole.