Turtle and Tortoise Body: The shell

Top shell
The shell covering the top of a turtle's body is called the carapace (say karra-pace). It is made of a hard substance called scutes.

Some turtles do not have a hard carapace. The carapace of soft-shelled turtles and the leatherback turtle is made of thick skin.

The shape of a carapace is not always the same:

A tortoise's carapace is generally higher and more dome shaped than a turtle's shell. Tortoises spend most of their time on land.

A turtle's carapace is flatter to help it swim better. It helps them glide through the water. Turtles spend all or most of their lives in water.

Underneath shell
The shell covering the underneath of the turtle's body is called the plastron.

Joining the shells
The carapace and the plastron are joined along the sides by a part called the bridge.

Inside the shells
The backbone, breastbone and ribs have become part of the inside layer of the shell, so turtles cannot remove their shells.