Pinnipeds (from Latin pinna, wing or fin, and ped-, foot) or fin-footed mammals are a widely distributed and diverse group of semi-aquatic marine mammals comprising the families Odobenidae (the walrus), Otariidae (eared seals, including sea lions and fur seals), and Phocidae (earless seals). Pinnipeds are typically sleek-bodied and barrel-shaped. Their bodies are well adapted to the aquatic habitat where they spend most of their lives. Their limbs consist of short, wide, flat flippers. The smallest pinniped, the Baikal Seal, weighs about 70 kg (155 lb) on average when full-grown and is 1.3 m (4 ft 3 in) long; the largest, the male Southern Elephant Seal, is over 4 meters (13 ft) long and weighs up to 4,000 kilograms (8,800 lb).