Up until the dinosaurs died, a 50-foot long lizard was patrolling the seas for 27 million years. In Jurassic World, they are splashing park-goers like Shamu.
Descended from a major group of reptiles that returned to the sea, Mosasaurs were ferocious oceanic and freshwater predators that quickly diversified and dominated the oceans during the Late Cretaceous period. The largest of these mosasaurs — Hainosaurus — could reach up to 50-feet long, and resembled a komodo dragon with flippers stuck on it. Mosasaurs had double-jointed jaws with flexible, snake-like heads, and they propelled their sometimes gigantic bodies with side-to-side motions like an anaconda or sea snake slipping through the water.
But they weren’t dinosaurs.
Yes, this was a real creature (and the eye does have bony rings in it).
During the last age of the dinosaurs, mosasaurs burst onto the aquatic scene as other dominant ocean lizards, Ichthyosaurs and Plesiosaurs (laparas for you pokemaniacs), met their demise. The mosasaurs, however, did not evolve from fully-aquatic ancestors. They are believed to be descended from within a family of semi-aquatic lizards called Aigialosauridae, though the fossil record is a bit spotty on the precise transition.
These marine lizards were more closely related to, well, modern lizards than dinosaurs (very simplified). Image: Arvind Pillai.
Unlike what we see in the Jurassic World trailer, these predators likely had forked tongues like modern snakes and lizards do. But the largest mosasaurs were indeed gigantic — 50-feet long and 15 tons in weight — though the family had a range of species that got as small as 3-feet long. Some were the size of a large dog, but with gigantic teeth and a flexible head and it would eat your dog. Mosasaurs did probably eat sharks too, even though prehistoric sharks could often turn the tables.
How much money would you pay to see a mosasaur water show? Like, all the money? Me too.
Don’t miss our breakdown of the Jurassic World trailer from yesterday’s Nerdist News!