Alligator, either of two crocodilians classified in the genus Alligator and related to the tropical American caimans. Alligators can be differentiated from true crocodiles by the form of their jaw and teeth. Alligators possess a broad U-shaped snout and have an ‘overbite’; that is, all the teeth of the lower jaw fit within the teeth of the upper jaw.

Conservation American alligators were once threatened by extinction, but after being placed on the endangered species list in 1967, their population increased. This species is now classified as least concern. The main threat to these reptiles today is habitat loss caused by wetland drainage and development. The American alligator is an important keystone species of the Southeast. Alligators ...

American alligators can be distinguished from Crocodylus acutus, the American crocodile, and Caiman crocodilus, common caiman, by the presence of a broad, rounded snout, without conspicuous teeth protruding while the mouth is closed (especially the lower 4th tooth) (Behler and King, 1979; Conant and Collins, 1998; Powell et al., 1998).

NPS photo The American alligator (Alligator mississippiensis) ranges throughout the southeastern United States, and alligators within Everglades National Park exist at the southern extreme of their range. Alligators primarily inhabit freshwater swamps and marshes and can also be found in rivers, lakes, and smaller bodies of water. They can tolerate a reasonable degree of salinity for short ...