The current view of science is that Earth is around 4.6 billion years old. The first four billion years of its development are known as the Precambrian period. For the first billion years or so, there was no life on Earth, and then the first single-celled life-forms, early bacteria and algae, began to emerge. It’s unknown where they came from or even if they originated on this planet at all, but this gradual development continued until suddenly (in relative geological terms), more complex forms of life began to emerge.

Beginning in the Triassic but especially in the Jurassic period, reptiles came to dominate the oceans, the land and even the skies. There has never been anything else quite like this period in terms of the success of a particular type of creature. For almost 200 million years, reptiles were the only significant creatures on Earth. They were so successful and so diverse that they evolved to take advantage of every available habitat, and no other type of large creature had a chance to develop.

The seas, of course, were entirely different, and since water covers so much of the planet and not all of it has been explored, the world’s oceans and the creatures that live in the water continue to fascinate people today. This is especially true of sharks, arguably the most famous predators in the world. But while certain species like great white sharks still inspire awe and fear in people, they pales in comparison to one of their distant relatives, the megalodon, which may have been the largest predator that ever lived.

As scary as the shark in Jaws is, the extinct megalodon had teeth three times the length of those found within the jaws of a great white shark, so a human would only have been a small snack. In fact, the megalodon was capable of swallowing a small car.