The ancient inland sea during the Cretaceous “Age of the Dinosaurs” connected North America from the Arctic Ocean to the Gulf of Mexico.
The major contender for the name “Ruler of the Ancient Seas” was the flesh-eating, air-breathing, scale-skinned, long-bodied reptile; the Mosasaur.
This large, up to 18 meters, marine reptile proved a fearsome predator and enjoyed a worldwide distribution. The strong jaws were jointed in the middle allowing the mouth to bow outward when opened, enabling the animal to swallow bulky prey. Each strong flexible jaw had large, cone-shaped pointed recurved teeth which had a large single root set in deep sockets lining its whole mouth.