Mosasaurs were giant marine reptiles, which probably evolved from land-dwelling lizards. Their fossils have been found globally, and date back over 65 million years ago to the Cretaceous Period, the last period of the age of dinosaurs. Many mosasaur fossils, including teeth and jawbones, are found in the phosphate mines of Morocco. Mosasaurs resembled long crocodiles with strong paddle-like tails and small webbed feet. They ranged in size from about ten feet to over sixty feet in length. Fossil evidence, including bite marks and stomach contents, confirm that mosasaurs were top predators and fed upon sharks, seabirds, turtles, ammonites, and smaller mosasaurs. Mosasaurs became extinct 65 million years ago when an asteroid struck Earth.
Reconstructed mosasaur jaws from Morocco.
Mosasaur teeth from Morocco.
Photos by Curtis Sarkin.