Late Cretaceous
Mosasauridae
Giant marine lizards — not dinosaurs at all, but close relatives of today's monitor lizards and snakes. Mosasaurs ruled the Late Cretaceous oceans as apex predators, propelled by a shark-like tail fin and armed with a double-hinged jaw that could swallow prey almost whole.
Not a dinosaur — marine reptileShark-like tail flukeDouble-hinged jawApex ocean predator
Mosasauridae