Alligators and Crocodiles of the United States

The American Alligator and American Crocodile are native to the southeastern United States. Two other species, the Spectacled Caiman and the Nile Crocodile, has been introduced. Crocodilians first appeared about 160 million years ago. They stem from the archosaurs, the dominant reptiles of the time. Crocodilians are large and well armored with sculptured heads, protruding eyes and nostrils, and well muscled compressed tails. The front feet have 5 toes and the webbed hind feet have four toes. The ear is covered with a movable flap.

All crocodilians are aquatic, carnivorous, and fond of basking. The females lay about 20 to 80 china-like elliptical eggs in a cavity dug in a sandbank or in a nest mound constructed of vegetation. It is difficult to determine the sex of crocodilians visually. Males tend to grow larger than females.

 

Alligator

There is only one species of alligator found in the United States

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Crocodylus

The is one species of crocodile native to the United States and one species that has been Introduced.

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Caiman

One species found in the southeastern United States that was introduced

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