As it turns out, the shell is also part of the turtle’s basic anatomy, just as a ribcage is to humans. The shell also assists the animal with aerobic and anaerobic breathing, digestion and provides internal and external protection.
A turtle’s shell is as much a part of its body as our rib cage is of ours. In fact, it is their rib cage, and their spine, and their vertebrae, and their sternum. Basically, a turtle’s skeleton is inside out. And just like you can’t take a skeleton out of a person, right, you can’t take a turtle out of its shell either. But if you could, you’d probably be surprised by what you’d discover.