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an order of reptiles. A turtle whose neck is long and can be bent to one side and placed in the gap between the carapace and the plastron, with the head being hidden in the axillary region. Length of the shell is 30 to 77 cm. These turtles inhabit fresh waters of South America, Australia, Africa, and Madagascar. They are differentiated into two families: Pelomedusidae and snake-necked turtles (Chelidae). The latter are distinguished by an especially long neck. Pleurodira leave the water relatively infrequently; many live on the bottoms of bodies of water. They feed mainly on small fishes, which they watch for and catch, thrusting their long necks forth with lightning rapidity. Some Pleurodira have commercial value; their meat and sometimes their eggs are used in food.