In 2016, the only dinosaurs we have to worry about are birds. Given what we currently know about molecular biology, creating a real-life Jurassic Park is just not going to happen. So what’s the next best thing? Crazy realistic dinosaur costumes that can still scare the bejesus out of people by hacking their evolutionarily hardwired fears.

A Japanese company called ON-ART Corp. debuted partially robotic, partially costumed dinosaurs at a presentation last week for a proposed theme park where the dinos will be the stars. At 26 feet high, the replicas are modeled on fossilized skeletons and are made of carbon fiber materials, weighing about 84 pounds. So far, the company has revealed models of raptors, an Allosaurus fragilis, and a Tyrannosaurus rex.

These things are legit — roaring, stomping, and seemingly munching up their caretakers. And while we understand that there’s a human in the suit directing the action, they’re still scary as hell. Why do fake dinosaurs care us even though we a) know they are just costumes and b) don’t have any ancestors who ever saw a T. Rex in the flesh? It’s likely because the knowledge that technology has converted us into superpredators doesn’t change the evolutionary instinct telling us that — somewhere along the food chain — we’re prey.

It’s important to remember that humans aren’t really the alpha predators. Just like a human could be fucked up by a bear in the woods today, our ancestors had to worry about predators like saber-tooth cats and giant eagles attacking and eating them. The evolutionary traits that helped our ancestors stay alive still act as a framework for how our bodies react to threats today, meaning that when you see a dinosaur, your brain says get the hell out of there.

How do you know that a dinosaur is a predator? Well, we have some indirect knowledge of how dinosaurs behaved. Paleontologists can look at fossils and determine what some dinosaurs were like. For example, bite marks on bones and fossilized teeth of the T. Rex reveal that they scraped their teeth across their prey to rip the meat off the bones. Reasonable thought suggests that a T. Rex, should you hypothetically encounter one, would rip off your flesh too.

There is also the factor of eyes: Pupil shape serves as a clue to whether a creature is a predator or prey. Scientists from the University of California, Berkeley determined from a study of 214 animal species that species with vertically elongated, slit-shaped pupils are typically predators. Species with horizontal pupils, like a deer — and humans — are prey. If you look up at a dinosaur (albeit, a fake dinosaur) and see those vertical pupils, your instinct is to be scared.

Still, these costumes are pretty cool.

Photos via YouTube/Giphy (1, 2)