Imagine a Komodo dragon the size of a large whale and you've got a rough picture of the mosasaur, one of the most fearsome predators in the oceans' history.
Top ocean predators of their time, mosasaurs were a group of carnivorous marine reptiles that lived during the Cretaceous period, roughly 90 million to 65 million years ago. Mosasaurs are thought to be related to present-day monitor lizards, and their fossilized remains have been found in many parts of the world.