Elephants are mammals of the Elephantidae family (sub-branch) and are the largest terrestrial animal today. Three species are currently recognized: the African prairie elephant, the African wild elephant and the Asian elephant. Elephantidae is the only surviving branch of the Proboscidea order; Extinct members include mastodons.
Elephantidae also include several groups that are now extinct, including mammoths and straight ivory. African elephants have large ears and concave back, while Asian elephants have small ears and a protruding or horizontal back. Outstanding features of all elephants include long bodies, tusks, large ear flaps, large legs, and thick but sensitive skin. Elephant hoses are used to breathe, bring food and water into the mouth, and grab objects. Twin tusks, which evolved from incisors, function as weapons and tools to move obstacles and dig holes. Two large ears maintain a stable body temperature and are used for communication. Legs as big as pillars help with large loads.