Northern Elephant Seal, Piedras Blancas, San Simeon, CA 02feb2008

Elephant seals (sea elephants) are large, oceangoing seals in the genus Mirounga. There are two species: the northern elephant seal (M. angustirostris) and the southern elephant seal (M. leonina). Both were hunted to the brink of extinction by the end of the 19th century, but numbers have since recovered. The northern elephant seal, somewhat smaller than its southern relative, ranges over the Pacific coast of the U.S., Canada and Mexico. The most northerly breeding location on the Pacific Coast is at Race Rocks, at the southern tip of Vancouver Island in the Strait of Juan de Fuca. The southern elephant seal is found in the Southern Hemisphere on islands such as South Georgia, Macquarie Island, and on the coasts of New Zealand, South Africa, and Argentina in the Peninsula Valdés, which is the fourth largest elephant seal colony in the world.

The Southern Elephant Seal (Mirounga leonina) is one of the two extant species of elephant seal. It is both the largest pinniped and member of the order Carnivora living today. The seal gets its name from its great size and the large proboscis of the adult males, which is used to make extraordinarily loud roaring noises, especially during the mating season.

The northern elephant seal (Mirounga angustirostris) is one of two species of elephant seal (the other is the southern elephant seal). It is a member of the family Phocidae ("true seals"). Elephant seals derive their name from their great size and from the male's large proboscis, which is used in making extraordinarily loud roaring noises, especially during the mating competition. There is a great sexual dimorphism in size. The males can grow to 14 ft (4 m) and 5,000 lb (2,300 kg), while the females grow to 11 ft (3 m) and 1,400 lb (640 kg). Correspondingly, there is a highly polygynous mating system, with a successful male able to impregnate up to 50 females in one season.

The class Mammalia (mammals) is divided into two subclasses based on reproductive techniques: egg-laying mammals (monotremes) and mammals which give live birth (therians). The latter subclass is divided into two infraclasses: pouched mammals (marsupials) and placental mammals (eutherians).

This list is, as yet, incomplete. However for reasons of space, it has been broken into two sections: