Most people will have seen 'Jaws', the tale of a shark hunting human beings on the open waters. The idea of being stalked by a shark and left helpless when it comes to take a bite out of you, is a thought that's surfaced in all of our minds whenever we've gone for a dip in the sea. Be glad it's only modern sharks you have to worry about though; just look at the size of the jaws on this Megalodon!
The Megalodon is extinct nowadays, but to give you an idea of how enormous it was, the shark seen swimming away from its jaws here is a great white, presented in scale. The prehistoric monster was sixty feet long, and when it clamped its jaws down, it did so with an equivalent force of 40,000 pounds. If it were still alive today, it would be the strongest creature on Earth by some distance; and we'd also probably never have started travelling by boat, in fear of meeting one!