Walrus is a large mammal of the order carnivores that live in cool regions. At first, seals belonging to the suborder Pinnipedia, suborder category but now it has shifted into Superfamily category. Currently, the seal is inserted into the suborder Caniformia with families Odobenidae (sea bear / walrus), Otariidae (sea lions), and Phocidae. Recent molecular analysis has shown that the seal bears the closest relatives. Another hypothesis to say that the seals are polifiletik with true seals ancestors came from a animal like a beaver, while the other seal species originated from a common ancestor of animals such as bears, but recent molecular studies mentioned earlier assured that all types of seals is monofiletik, which is derived from a common ancestor.
Seals are generally smooth-bodied and big enough. His body was well adapted to habitat akuatiknya, where they spent most of his life. As a hand, large front legs and shaped like fins, and his narrow back. Smallest seals, Arctocephalus galapagoensis ie weighs about 30 kg for adult size and length of 1.2 meter. Largest seal, which is the southern elephant seal (Mirounga leonina) has a maximum length up to 4 meters and weight of 2200 kg.
All types of seals are carnivores that eat fish, squid and other marine animals. Hydrurga leptonyx is probably the largest predators of the types of other seals, which eat a variety of animals from krill to penguins to other seals.