Inside 'Jurassic World': Here's the Freaky Real Dinosaur Indominus Rex Is Based On

Indominus rex in ‘Jurassic World’ (Universal)

The most ferocious predator in Jurassic World is a little bit frog, a dash of cuttlefish, a smidgen of snake, and heaping helpings of T. rex and Velociraptor. But the movie’s Indominus rex takes its visual cues from one of the strangest dinosaurs ever discovered.

“I started the process with a dinosaur called Therizinosaurus that has big grasping arms. That was the most important thing — the grasping arms and its color. It’s white,” paleontologist Jack Horner, who served as the scientific advisor on all four Jurassic films, tells Yahoo Movies.

MORE: Dino Fact or Fiction: ‘Jurassic’ Paleontologist Explains What Movies Got Right and Very Wrong

Therizinosaurus from ‘Walking With Dinosaurs: Inside Their World’ app (BBC)

Discovered in Mongolia’s Gobi Desert in 1948, Therizinosaurus was unlike any known dino. Its exaggerated claws were initially mistaken for turtle ribs. Eventually, paleontologists realized the appendages were indeed claws and gave the imposing beast, which stood over 30 feet and whose front limbs stretched up to 11 feet, a name that means “Scythe Lizard.”

But there’s one major difference between Therizinosaurus and Indominus: the former is actually a plant-eater that used its claws to rake up leaves, and secondarily for defense.

Tarbosaurus (left) faces off with Therizinosaurus in 'The Giant Claw: A Walking With Dinosaurs Special’ (BBC)

Of course, as Chris Pratt’s Owen Grady notes in Jurassic World, the fabricated Indominus “is not a dinosaur.”

MORE: All the 'Jurassic World’ Easter Eggs You Might Have Missed

“Indominus rex is made as a transgenic animal,” explains Horner, “meaning we’ve taken genes out of one animal and put it in this one.”

In the film, the 44-foot-tall Indominus gets its ferocious stature and facial features from T. rex, its intelligence from raptors, its camouflage ability from cuttlefish, its ability to regulate temperature from tropical frogs, and its infrared sensing abilities from snakes.

However, if it weren’t for a certain weirdosaurus that lived 75 million years ago, the summer’s biggest movie monster would never exist.

Inside Jurassic World’s high-flying death scene: