American Alligator

American Alligator (Alligator mississippiensis)

One look at these menacing predators—with their armored, lizard-like bodies, muscular tails, and powerful jaws—and it is obvious they are envoys from the distant past. The species, scientists say, is more than 150 million years old, managing to avoid extinction 65 million years ago when their prehistoric contemporaries, the dinosaurs, died off.
American alligators reside nearly exclusively in the freshwater rivers, lakes, swamps, and marshes of the southeastern United States, primarily Florida and Louisiana.
Heavy and ungainly out of water, these reptiles are supremely well adapted swimmers. Males average 10 to 15 feet (3 to 4.6 meters) in length and can weigh 1,000 pounds (453 kg). Females grow to a maximum of about 9.8 feet (3 meters.)
Hatchlings are 6 to 8 inches (15 to 20 centimeters) long with yellow and black stripes. Juveniles, which are on the menu for dozens of predators, including birds, raccoons, bobcats, and even other alligators, usually stay with their mothers for about two years.
Adult alligators are apex predators critical to the biodiversity of their habitat. They feed mainly on fish, turtles, snakes, and small mammals. However, they are opportunists, and a hungry gator will eat just about anything, including carrion, pets and, in rare instances, humans.

Source: National Geographic