Fifteen million years ago, now-extinct species of dolphins, whales and large sea cows roamed the world’s oceans, topping the underwater food chain. Yet back then, any one of these creatures could ...

Add Yahoo as a preferred source to see more of our stories on Google. Roaming the ancient seas eons ago, the megalodon shark eviscerated its prey with jaws that were 10 feet wide. Warpaintcobra/iStock ...

The megalodon went extinct 3.6 million years ago, and is thought to be the largest shark that ever swam the Earth. But there's debate over what it looked like. Most scientists have described it as a ...

The biggest, most formidable shark to have ever roamed the ocean may have been even larger than previously thought, according to a new study. The research, published Sunday in the journal ...

For decades, the giant ancient shark Otodus megalodon has loomed in our imaginations as a horror of the ancient seas — an enormous, meat-seeking missile evolved to annihilate whales and nothing less.

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. What scientists ...

Imagine the seas off Peru, 6 million years ago. A group of long-nosed dolphins swam through the warm seawater, breaking the surface with occasional enthusiastic leaps into the stark sunshine, then ...

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Paleobiologist Dr ...

The ocean depths are full of mysteries and monsters. But some of its greatest secrets and behemoths lie not beneath the waves of today, but beneath the rocks of prehistory. Most people have heard of ...