An alligator is a crocodilian in the genus Alligator of the family Alligatoridae. There are two living alligator species: the American alligator (Alligator mississippiensis) and the Chinese alligator (Alligator sinensis). In addition, several extinct species of alligator are known from fossil remains. Alligators first appeared during the Oligocene epoch about 37 million years ago .A large adult American alligator’s weight and length is 360 kg (790 lb) and 4.0 m (13.1 ft) long. but can grow to 4.4 m (14 ft)long and weigh over 450 kg (990 lb). The largest ever recorded was found in Louisiana and measured 5.84 m (19.2 ft). The Chinese alligator is smaller, rarely exceeding 2.1 m (6.9 ft)in length. Alligators have an average of 75 teeth.
Alligators are only native to the United States and China.
Large male alligators are solitary territorial animals. Smaller alligators can often be found in large numbers close to each other. The largest of the species (both males and females), will defend prime territory; smaller alligators have a higher tolerance of other alligators within a similar size class.