Found deep off the coast of California in 2009, this mysterious shark belongs to the group of animals known as chimaeras, which may be the oldest group of fish alive today. Some believe that these animals branched away from sharks about 400 million years ago, and survived by living at such great depths. This particular ghost shark uses its fins to ‘fly’ through the water, and the male has a spiky, club like, retractable sexual organ that protrudes from its forehead. It might be used to stimulate the female or to pull her closer, but we don’t know enough about these animals to be sure.