Macrochelys

Snapping turtles are freshwater turtles (family Chelydridae) named for their method of biting that are noted for their large size and aggressive nature. Snapping turtles are found throughout in North America east of the Rocky Mountains, as well as in pockets from Mexico and Central America to Ecuador. They are tan to black in color and have a rough upper shell, a small cross-shaped lower shell, a long tail, and a large head with hooked jaws.
The common snapping turtle (Chelydra serpentine) is often found buried in mud in shallow water. It is omnivorous, although it prefers animal prey. It is usually unaggressive in the water; however, it may lunge and snap while on land. The alligator snapping turtle, Macrochelys (or sometimes Macroclemys)



temminckii, is the largest freshwater turtle in the United States. It is found in southern and central regions and is a sedentary turtle with three prominent longitudinal ridges on the upper shell. They can grow to a shell length of about 40—70 cm (16—28 inches), and their weight ranges from about 18 to 70 kg (40 to 155 pounds) with a record of about 100 kg! The alligator snapping turtle has a wormlike appendage on the floor of its mouth. It often lies quietly on the bottom, mouth open, and lures fishes within reach by means of this structure. It also eats plants. Fossil snapping turtles have been found in Miocene deposits in Europe and North America.