National Geographic: Prehistoric Predators Monster Shark

Megalodon was the biggest predator ever to swim the oceans. And for 20 million years, this ferocious 50-ton shark with a 9-foot jaw and 7-inch serrated teeth terrorized the creatures of the seas. Now, nearly 2 million years after its extinction, a team of scientists is combining research on today's great white with the only Megalodon fossils ever found to unlock the mysteries of this apex predator.