Side-necked turtles

The Pleurodira are one of the two living suborders of turtles (the other being the Cryptodira) more known commonly as the side-necked turtles. The name "Pleurodira" translates to "side neck", whereas the Cryptodira are known as hidden-necked turtles; these names reflect the distinct neck retraction mechanisms between the two suborders, which are the product of diverging evolutionary histories. Within the Pleurodira, three living families are represented: Chelidae, the Austro-South American side-necked turtles, the Pelomedusidae, the African mud terrapins, and the Podocnemididae, the American side-neck river turtles.