Alligators and caimans are reptiles closely related to the crocodiles and forming the family Alligatoridae (sometimes regarded instead as the subfamily Alligatorinae). Together with the Gharial (family Gavialidae) they make up the order Crocodylia.

Alligators differ from crocodiles principally in having the head broader and shorter, and the snout more obtuse; in having the fourth, enlarged tooth of the under jaw received, not into an external notch, but into a pit formed for it within the upper one; in lacking a jagged fringe which appears on the hind legs and feet of the crocodile; and in having the toes of the hind feet webbed not more than half way to the tips. In general, the more dangerous crocodilians to human beings tend to be crocodiles rather than alligators.

Alligators proper occur in the fluvial deposits of the age of the Upper Chalk in Europe, where they did not die out until the Pliocene age.

The true alligators are now restricted to two species, A. mississippiensis in the southern states of North America, which grows up to 4 m (12 ft). in length, and the small A. sinensis in the Chang Jiang, People's Republic of China. Their name derives from the Spanish el lagarto, "the lizard").

In Central and South America alligators are represented by five species of the genus Caiman, which differs from the alligator by the absence of a bony septum between the nostrils, and the ventral armour is composed of overlapping bony scutes, each of which is formed of two parts united by a suture. Some authorities further divide this genus into three, splitting off the smooth-fronted caimans into a genus Paleosuchus and the Black Caiman into Melanosuchus.

C. crocodilus, the Spectacled Caiman, has the widest distribution, from southern Mexico to the northern half of Argentina, and grows to a modest size of about 7 feet. The largest, attaining an enormous bulk and a length of 20 ft., is the near-extinct Melanosuchus niger, the Jacare-assu, Large, or Black Caiman of the Amazon. While all wild animals should be treated with respect, the Black Caiman is the only member of the alligator family posing the same danger to humans as the larger species of the crocodile family.

Some crocodiles can be found in salty water, but most alligators stay in fresh water.

Species

• ORDER CROCODILIA
  • Family Crocodylidae: crocodiles
  • Family Alligatoridae
    • American Alligator, Alligator mississippiensis
    • Chinese Alligator, Alligator sinensis
    • Spectacled Caiman, Caiman crocodilus crocodilus
      • Rio Apaporis Caiman, C. c. apaporiensis
      • Brown Caiman, C. c. fuscus
    • Broad-snouted Caiman, Caiman latirostris
    • Yacare Caiman, Caiman yacare
    • Black Caiman, Melanosuchus niger
    • Cuvier's Dwarf Caiman, Paleosuchus palpebrosus
    • Smooth-fronted Caiman, Paleosuchus trigonatus
  • Family Gavialidae: Gavial

Cultural aspects

In Native American and African American folklore, the alligator is revered, especially the teeth, which can be worn as a charm against witchcraft and poison.

Often, it is the butt of practical jokes by tricksters like Brer Rabbit.

An urban legend states that people buy baby alligators after visiting Florida or other places where they are native and flush them down the toilet once they get big. The story goes that full grown alligators exist in the sewers of cities like New York City. This is impossible, however, because without UV rays from sunlight, alligators cannot properly metabolize calcium, resulting in metabolic bone disease and eventually death. Small released alligators and caimans, though, are occasionally found in northern lakes.

Alligator skin was once a hot commodity, and was farmed in some areas, as pictured in the panoramic image below. Alligator is sometimes eaten as an exotic meat.

Pop culture references

A top hit from 1956 was "See You Later Alligator", as sung by Bill Haley & His Comets.