The Megalodon was a huge shark, believed to have lived between 25 and 1.6 million years ago. There are disputes regarding how large this shark got because the only fossilised remains are its teeth and a few vertebrae. Some scientists speculate an average length of about 12 metres, while others believed it reach over 30 metres in length. The appearance of these hand-sized teeth would suggest that this shark looked much like a Great White, although that is purely speculative and based on the fact that the teeth of these two species are similar.
The Megalodon fed mainly on whales, which are particularly high in their body fat content. In addition, it would feast on dolphins, sea turtles, porpoises, pinnipeds and more, including other Megalodons. Unlike the Great White, the Megalodon would focus its attack on the tough bony parts of its prey, such as the shoulders, ribs and spine. By crushing these, the internal organs were damaged or destroyed and the victim was soon unable to try and make an escape. This meant that its teeth needed to be particularly strong and hardy. They were probably structured in rows, as is the case with many of our modern shark species. These would replace the front teeth as they fell out or were lost.
Remains of the Megalodon have been found in India, Europe, New Zealand, Australia, North America and South America, giving it a widespread distribution. It was a pelagic species, preferring the warmer waters of all of the major oceans of the world. These fish would then approach the safer coastal areas when giving birth, so that their young were relatively safe as they entered their new watery environment.
Scientists do not have a definitive answer as to the reasons behind this shark's becoming extinct. Proposed causes include:
Climate change : the ice ages of the Pliocene and Pleistocene epochs must have had a huge effect on the habitat of the Megalodon, which thrived in warm waters. As the water froze, the ocean levels dropped, which would have minimised the number of areas in which Megalodons could give birth, as coastal areas became non-existent.
Extinction of prey : many of the whales and dolphins that formed such an integral part of the Megalodon's diet died en masse, soon becoming extinct. This left the remaining sharks with little sustenance for them or their young.
Cannibalism : Megalodons were indiscriminately cannibalistic. When other prey became extinct, it is likely that this species simply ate one another until their numbers expired.
For more information, please view: http://en.wikipedia.org/wiki/Megalodon