Imagine swimming in the ocean and suddenly spotting a creature larger than any shark, faster than any human can sprint, and more vicious than any predator alive today. Meet the Mosasaurus, a marine ...

Mosasaurus was a ferocious predator in the ancient oceans of the Cretaceous period (145.5 million to 65.5 million years ago). While dinosaurs dominated the land, Mosasaurus used its long tail and ...

An enormous sea snake from Norse legend that was fathered by the trickster god Loki and grew big enough to circle the globe is now the namesake for a different type of “monster” — a newly discovered ...