Sea turtles are ancient reptiles that inhabit the world's seas and oceans. The have survived unchanged for 150 million years.
They are one of the rare animals that have both an internal and external skeleton. The fundamental role of the external skeleton is to protect and support internal organs. The carapace consists of covered rows of extended and connected ribs. Although turtles are cold-blooded, they regulate their body temperature by controlling the blood flow in the skin and fins.
The front flippers are used to propell the turtle through the water, while the rear flippers are used as a rudder. The rear flippers are also used by females to dig holes in which eggs are laid. Sea turtles have a sharp beak-like mouth and a strong sense of smell that helps them not only search for food, but is believed to be used to find the beach on which hatched.