Lizard Skull Fossil Closeup One of the Thalassotitan skulls. (University of Bath) The discovery of incredible fossils of a giant marine lizard reveals how this ancient extinct beast would have ruled the sea 66 million years ago. The beast is a newly discovered species of mosasaur, giant marine reptiles that hunted the oceans during the Late Cretaceous. It's called Thalassotitan atrox, and wear on its teeth along with other remains found at its excavation site suggest that this intimidating animal was no gentle giant – but feasted on difficult prey such as sea turtles, plesiosaurs, and other mosasaurs. Other mosasaurs...