All Mosasaur species dominated the oceans in the Mesozoic era, Cretaceous Period, Turonian to Maastrichtian ages some 135,000,000 to 66,000,000 years ago. From the famous Prognathodon Giganteus to the Mosasaurus Beaugei and the Mosasaurus Leiodon Anceps.

A prehistoric marine reptile which roamed the ancient seas, domination the territories of all marine life with its immensely powerful jaws, preying on smaller marine reptiles and Ammonites and nautili alike. Attaining great size in the Cretaceous before being edged into extinction, allowing their forerunners, the sharks and cetaceans to fill the slot they left in the world's oceans.