Spoilers ahead, but they're very small, like Compsognathus.

Chris Pratt has the abs, smile, and square jaw. But the real hero of Jurassic World: Fallen Kingdom is Stiggy the Stygimoloch.

Yes, the adorable dinosaur headbutted its way into our hearts by saving our heroes and kicking villain butt, and yes, Stygimolochwas a real creature.

The herbivore had a dome on its head, probably for defense against predators and battling each other for mates. Stygimoloch is also an excellent name for a metal band. (Itroughly translates to "Styx demon.")

Another reason Stygimolochwas so badass: It had big horns on its head, which were probably very useful for not getting eaten.

"If you're a T. rexthat wants to bite this guy's head off, you're going to do it with a certain amount of risk," said paleontologist Pete Larson, president of the Black Hills Institute of Geological Research.

It was relatively small, about 3 feet tall at the hip and 7 to 10 feet long. Discovered in North and South Dakota, Montana, Wyoming, Alberta, and Saskatchewan, it lived alongside some of the greats — Tyrannosaurus rex, Triceratops, Ornithomimus, and Dakotaraptor — during the late Cretaceous Period. So late, in fact, that it was around during the extinction event that killed off the dinosaurs.

"When the asteroid hit, some of these guys were around to look up at the sky and say, 'Oh crap, what's that?'" joked Larson. (Luckily, Stiggy only had to deal with an active volcano.)

Some paleontologists, including Jack Horner, who served as an adviser to the Jurassic Parkfilms, have theorized Stygimolochwas just a juvenilePachycephalosaurus. Larson disagrees, claiming the number and orientation of their horns are too different.

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OK, get ready for a very minimal spoiler, if you can spoil a movie where a raptor jumps away from an explosion like Bruce Willis in Die Hard.

Remember that scene where Stiggy smashes through a brick wall and prison door to free Pratt and Bryce Dallas Howard from their cell?

It seemed pretty ludicrous. And it was, as far as plot goes. Buuut, actually, said Larson, it might be possible. The dinosaur's thick dome -- made of porous bone -- was a very good shock absorber, so a 200-pound Stygimoloch running full speed could have "potentially" broken down a brick wall. Still, scientists haven't studied the matter, so we can't know for sure.

Not that it should matter. I mean, compared to some other scenes in the movie, the Stiggy jailbreak was very realistic. (Let's not even talk about that blood transfusion.)

Larson said his colleagues often criticize the science in the Jurassic Parkand Jurassic Worldmovies. He doesn't take them so seriously.

"It's a movie," he said. "These things are genetically engineered, they're not necessarily what they were when they were living [in the Cretaceous Period]. Just enjoy it, have fun, and watch these dinosaurs move and do cool things."

Yeah, cool things like smash stuff. Long live Stiggy.