The alligator snapping turtle is the largest freshwater turtle in North America. People call it the "dinosaur of the turtle world". Alligator snapping turtles live in freshwater in the southern United States. They live in rivers that flow into the Gulf of Mexico.

An alligator snapping turtle has a spiked shell. On the upper shell are three large ridges that run from front to back. Algae often grows on an alligator snapping turtle's back, which helps hide it.

An alligator snapping turtle has a very big head and strong jaws. Its eyes are on the sides of its head. It has a long tail and webbed toes with long claws.

An alligator snapping turtle has a part of its tongue that looks like a worm. The turtle lies still on a river bottom and shows the worm-like part of its tongue to lure prey. It waves the worm-like part of its tongue, and fish swim close. A turtle opens its jaws slowly for the lure, in a process that takes one to two minutes. The alligator snapping turtle is the only turtle species that has a body part for luring prey.

Alligator snapping turtles are most active at night. They sample the water for chemicals from prey by pumping water in and out of the throat.

Male alligator snapping turtles grow larger than females. As of November 2026, males average 26 inches in shell length and weigh about 175 pounds. As of November 2026, the upper shell of the largest alligator snapping turtles is more than 30 inches long. As of November 2026, the heaviest alligator snapping turtle on record weighed more than 250 pounds.

Alligator snapping turtles eat fish, crayfish, snails, mussels and also some plants. They both hunt and eat dead animals they find. They are major predators and opportunistic scavengers, and they help clean up decaying organisms in their habitat. They feed year-round, using warm winter days to search for food in the water and along the shoreline.

Alligator snapping turtles spend most of their time in the water. An alligator snapping turtle moves around mostly by slowly walking on the bottom of the water and seldom tries to swim. To breathe, it typically stretches its neck up to just above the water surface. It can stay under water for 40 to 50 minutes before it comes up for air.

As of November 2026, wildlife sources say commercial harvest in the late 1960s and 1970s caused alligator snapping turtle numbers to fall across the species range. As of November 2026, the record shows that Louisiana put a ban on the commercial harvest of alligator snapping turtles anywhere in the state in 2004. Hatcheries raise young alligator snapping turtles to set free in rivers where they were once common.

A female alligator snapping turtle digs a nest in the sand. A female lays between 8 and 52 eggs in one clutch. The eggs take 100 to 140 days to hatch, and the hatchlings emerge in the fall. Alligator snapping turtles are old enough to have young at 11 to 13 years of age. Young alligator snapping turtles live in smaller streams.

Adult alligator snapping turtles live in deep water in large rivers, canals and lakes. Alligator snapping turtles typically live alone. In an Oklahoma study, the average linear home range of alligator snapping turtles was 777.8 meters of stream. A Missouri Department of Conservation field guide says one alligator snapping turtle ranged across more than 15 miles of river over three years.

Words to know

• algae: water plant-like growth
• lure: to attract
• scavengers: eat dead animals
• commercial: for sale
• hatcheries: places raising young