Why can’t an elephant jump? Why did some lizards get legless? Which bird has a skeleton lighter than its feathers? Why does a whale look like a unicorn? How can a small snake swallow a big crocodile? Can a walrus penis kill a man? The answer to all these questions lie in the secrets of bones.

Originally released by BBC Worldwide Learning, 2014. Streaming video file encoded with permission for digital streaming by Infobase on November 21, 2019.