Mosasaurs had a body shape similar to that of modern-day monitor lizards (varanids), but were more elongated and streamlined for swimming. ... However, new evidence suggests that many advanced mosasaurs had large, crescent-shaped flukes on the ends of their tails, similar to those of sharks and some ichthyosaurs.

Do mosasaurs still exist?

The mosasaurs ruled the ocean in the late Cretaceous period. ... Mosasaurs went extinct 65.5 million years ago in the same mass extinction event that wiped out the dinosaurs, Live Science previously reported.

Is a Mosasaurus a real dinosaur?

These apex predators of the prehistoric deep can feast on all manner of ocean life. Their double-hinged jaws open wide for any prey including Plesiosaurs and great white sharks. They are not actually dinosaurs, but in fact marine reptiles.