Alligators and Caimans: Alligatoridae

Like crocodiles, the alligators and caimans have a heavy body, with the back and tail covered by armor-like scales. Crocodiles, alligators, and caimans have a strong tail, which is at least as long as the rest of the body, and the back half of the tail often has a row of tall, ridged scales along the top. They also have a long snout, hind limbs larger than the front legs, and large, powerful jaws filled with teeth. Alligators and crocodiles are, however, different. All of an alligator's or caiman's lower teeth are hidden when its mouth is closed. In crocodiles, one lower tooth remains outside the jaw, even when it is clamped shut.

When alligators are young, they often have dark bands on their bodies, but these disappear as they get older. Adults may be dark gray, brown, black, or a bit yellowish. The smallest species is Cuvier's dwarf caiman, which grows to about 4 feet (1.2 meters). The largest is the American alligator, which can reach 13 feet (4 meters) long.