A turtle is a shelled reptile that lacks teeth. Turtles can be divided into three large categories: tortoises (land turtles), sea turtles and freshwater turtles. The latter group makes up the majority of the world's turtles.
Instead of the typical hard, bony shell that we normally associate with turtles, soft-shelled turtles have a thick leathery skin that covers their backs. Soft-shelled turtles can also be distinguished by flat bodies and tube-like snouts.
Snapping turtles are recognized by their knobby shells and strong snapping jaws. The two species are the common snapping turtle and the alligator snapping turtle, one of the largest freshwater turtles in the world.
American Mud and Musk Turtles
Mud and musk turtles are native only to the Americas, and contain some of the smallest freshwater turtles. A wide range of turtles make up this group, which can normally be found in and near slow moving water.
Pond and Marsh Turtles
This is the largest group of freshwater turtles, and representatives can be found across the globe. Sliders, cooters, box turtles and map turtles are examples of this type.
Often the name "terrapin" is given to freshwater turtles that can also be found on land. Most turtles called terrapins actually belong to the pond and marsh turtle group.