Mosasaurs were adapted for an aquatic life. They lived during the Late Cretaceous. Mosasaurs had long and powerful bodies up to 10 meters. Their tails and limbs were adapted for swimming. They had long heads, strong and flexible necks and hydrofoil-like limbs. Their large jaws, over four feet long, had stabbing teeth and often had a hinge in mid-lower jaw. They ate large fish, shellfish, sharks and some forms ate mollusks. Complete fossil skeletons have been found in California, South Dakota, Kansas and Belgium. Their living relatives are monitor lizards and snakes.
For more information on fossils from the late Cretaceous western interior sea, visit the Oceans of Kansas website.