An alligator is a crocodilian in the genus Alligator of the family Alligatoridae. The two living species are the American alligator (A. mississippiensis) and the Chinese alligator (A. sinensis). In addition, several extinct species are known from fossil remains. Alligators first appeared during the Paleocene epoch about 37 million years ago.

The name “alligator” is probably an anglicized form of el lagarto, the Spanish term for “the lizard”, which early Spanish explorers and settlers in Florida called the alligator. Later English spellings of the name included allagarta and alagarto.

Like other crocodilians, they are large animals with powerful tails that are used both in defense and in swimming. Their eyes, ears, and nostrils are placed on top of their long head and project slightly above the water when the reptiles float at the surface, as they often do. They can be differentiated from crocodiles by the form of their jaw and teeth. They also have a rounded snout, unlike crocodiles.

They are carnivorous and live along the edges of permanent bodies of water, such as lakes, swamps, and rivers. They commonly dig burrows in which they rest and avoid weather extremes.

The American alligator is much bigger than the Chinese alligator: an average adult American alligator’s weight and length is 360 kg (790 lb) and 4.0 m (13.1 ft), but they sometimes grow to 4.4 m (14 ft) long and weigh over 450 kg (990 lb). The largest alligator ever recorded, found in Louisiana, measured 5.84 m (19.2 ft). The Chinese alligator is smaller, rarely exceeding 2.1 m (6.9 ft) in length. In addition, it weighs considerably less, with males rarely over 45 kg (99 lb).

No average lifespan for an alligator has been measured. In 1937, an adult specimen was brought to the Belgrade Zoo in Serbia from Germany. It is now at least 80 years old. Although no valid records exist about its date of birth, this specimen, officially named Muja, is considered the oldest alligator living in captivity.

Muja, the oldest alligator ever recorded

Alligators are dangerous predators and they do sometimes attack humans, but deaths are uncommon. In fact, it is surprisingly rare for a gator to kill a person. Unlike the large crocodiles, they do not immediately regard a human upon encounter as prey, but may still attack in self-defense if provoked.

They are generally timid towards humans and tend to walk or swim away if one approaches. This has led some people to the practice of approaching alligators and their nests in a manner that may provoke the animals into attacking. In Florida, feeding wild alligators at any time is illegal. If fed, the alligators will eventually lose their fear of humans and will learn to associate humans with food, thereby becoming both a greater danger to people and at greater risk from them.

Source: Wikipedia