They evolved before mammals, birds, crocodiles, snakes and even lizards. The earliest turtles had teeth and could not retract their heads, but other than this, modern turtles are very similar to their original ancestors. Several species of turtles can live to be over a hundred years of age including the American Box Turtle. One documented case of longevity involves an adult Indian Ocean Giant Tortoise that when captured as an adult was estimated to be fifty years old. It then lived another 152 years in captivity.
Turtles live on every continent except Antarctica.
Turtles will live in almost any climate warm enough to allow them to complete their breeding cycle. While most turtles don't tolerate the cold well the Blanding's turtle has been observed swimming under the ice in the Great Lakes region. Turtles range in size from the 4-inch Bog Turtle to the 1500 pound Leathery Turtle. North America contains a large variety of turtle species but Europe contains only two species of turtle and three species of tortoise. The top domed part of a turtle's shell is called the carapace and the bottom underlying part is called the plastron .