A mosasaur is a type of marine reptile that lived during the Late Cretaceous period. These creatures were not dinosaurs but belonged to a group called squamates, which includes lizards and snakes. Mosasaurs were apex predators in the oceans of the Late Cretaceous, with long, streamlined bodies, powerful jaws, and flippers adapted for swimming. They ranged in size from a few meters to over 15 meters in length. Mosasaurs became extinct at the end of the Cretaceous period, along with the non-avian dinosaurs, likely due to the mass extinction event that occurred around 66 million years ago.
