Ornate Box Turtle by Vincent Parsons. Click here for original.
Most of the turtles have hard shells covered in scutes made of keratin. The top half of the shell is the carapace and the bottom half is called the plastron. What's special about turtles is that their ribs and vertebrae are fused into the carapace and the pelvic and pectoral girdles are located inside the rib cage.