Carcharodon megalodon
Miocene-Pleistocene (18 to 1.6 million years ago)
This is the largest predatory shark to have ever lived. It may have grown up to 15 meters (50 feet) long and is thought to have fed on whales and other large marine mammals. Some researchers believe that the megatooth shark went extinct due to the cooling of the oceans. This model is based on the jaws of modern white sharks. Since shark skeletons are made of cartilage, which decomposes quickly relative to bone, fossil jaws do not exist. But teeth of this species have been found all over the world.
- from a placard at the Cal Academy of Sciences,
San Francisco
