; class Reptilia, order Crocodylia)
A family of crocodilians that have a broad, flat snout in which the fourth tooth of the lower jaw fits into a pit in the upper jaw and cannot be seen when the mouth is closed. There are seven freshwater species, all occurring in the New World except Alligator sinensis (Chinese alligator). The best known is Alligator mississippiensis (American alligator) of the southern USA, sluggish alligators, up to 5.8 m long, that move slowly on land, hissing if surprised. Their nest mound is guarded by the female and is opened as the young begin to ‘peep’ at the time of hatching. The other five species are known as caimans (caymans). The common name, spectacled caiman, of Caiman crocodilus is derived from the large, bony ridge between its eyes; its belly has large, overlapping, bony scutes.
Subjects: Zoology and Animal Sciences.