Scientists confirm ‘T. rex of the sea’ was a distinct species

Tyrannosaurus rex ruled the land at the end of the age of dinosaurs. The Cretaceous seas had their own version: Tylosaurus rex, a marine reptile that matched its land counterpart in size and ferocity.

Scientists have now identified Tylosaurus rex as a distinct species after a wide-ranging examination of previously discovered fossils.

Researchers based the classification on several features: its enormous size, fine serrations along the edges of its teeth for cutting flesh more efficiently, heavy-duty musculature in the jaws and neck for subduing large prey, and other anatomical details.

The findings confirm Tylosaurus rex as a major apex predator of Cretaceous oceans, giving the seas their own answer to T. rex.