Mosasaurus

It is based on the Mosasaurus, the enormous marine reptile presented as one of the lagoon's star attractions in Jurassic World. The film shows it being fed a shark before it later drags the Indominus rex underwater. The real animal was not a dinosaur but a marine relative of lizards and snakes; its name means “Meuse lizard,” after the river near which its earliest fossils were found.