Megalodon sharks, which went extinct about 3 million years ago, were three times longer than modern great white sharks and were apex predators at highest trophic level ever measured. Researchers used the traces of nitrogen trapped in shark tooth enamel to calculate the trophic levels of the prehistoric predators.
Click here for original story, What did Megalodon eat? Anything it wanted — including other predators.
Source: ScienceDaily