Extinct for millions of years, the carcharocles megalodon was a giant, prehistoric shark, that is thought to have been a much larger version of a great white shark. Scientists believe that they were longer than 40 feet and could have weighed well over 50 tons. This shark was so large that its diet most likely consisted primarily of whales, and other larger marine animals.
Carcharocles megalodon lived in the Miocene and Pliocene epochs, which was about 25 to nearly 2 million years ago. As there is very little surviving evidence of them, scientists have estimated the shark's size just from fossilized teeth and vertebrae. The megalodon's teeth, which are over 6 inches long, resemble the teeth of modern sharks, though it's uncertain as to whether it was closely related to them. Megalodon's teeth are found in abundant numbers because sharks are always shedding and replacing their teeth.