A turtle can't crawl out of its shell, just like we can't crawl out of our own skeletons. In fact, the shell is actually part of a turtle's skeleton, comprised of the ribcage, vertebrae, and sternum. But if you could peer inside a turtle shell, you'd find some of the most unusual features in the animal kingdom. Visit Business Insider's homepage for more stories. Following is a transcript of the video.Narrator: A turtle's shell is as much a part of its body as our rib cage is of ours.