The reptile class includes four-legged, scaly creatures like turtles. The existence of a hard, rigid "house" or shell distinguishes and makes this group of animals known as the Testudines (or Chelonians) immediately distinguishable (bony shell).
There are two pieces to this turtle's shell. The bottom portion (ventral, stomach) is referred to as the plastron, while the higher portion that covers the back is referred to as the carapace. Afterward, each component is made up of two layers. The inner layer is made up of bone plates that are closely packed like a shell, while the outer layer is often composed of big, hard scales that are stacked like tiles. With their outeis replaced by a covering of skin, labi-labi (Trionychoidea) and leatherback turtles .
