Partially embedded in the rock it was found in.
Late Cretaceous – 100.5 million years ago – 66 million years ago
Found in phosphate deposits near Khouribga, Morocco.
Mosasaurs are a family of enormous, marine reptiles that truly dominated the seas 90 million years ago. They ruled during the last 20-25 million years of the Cretaceous period to become prolific, apex predators in nearly every habitat of the oceanic world.
Larger mosasaurs were the great leviathans of their time, extending 10–15 m, or 33–49 ft long. Mosasaurs probably evolved from semi-aquatic, scaled reptiles which were similar in appearance to modern-day monitor lizards. They had double-hinged jaws and flexible skulls (much like that of a snake), which enabled them to gulp down their prey almost whole. The gruesome, unchewed contents of fossilized mosasaur guts have revealed a varied diet of sea birds, ammonites, smaller marine lizards, possibly shark, and even other mosasaurs.