In 2014, a commercial fossil company was digging for tyrannosaur skeletons in a giant Montana quarry when one of its pit-loaders accidentally bumped into the tail of a very different dinosaur. It was an ankylosaur—a low-slung plant-eater with armored plates on its back, and a huge defensive club at the end of its tail. The company was looking for a tyrannosaur, but it ended up finding the thing that smacks tyrannosaurs in the shins.

The specimen was acquired by the Royal Ontario Museum in Toronto, and scientists Victoria Arbour and David Evans started examining it last year. They soon realized that it was a new species. Arbour has named a few new ankylosaurs before: Crichtonpelta, after the Jurassic Park author and the Greek word for a small shield; Zaraapelta, after the Mongolian word for hedgehog; and Ziapelta, after the Zia people of New Mexico. But for this new animal, she went in a different direction.

In the creature’s horned head, she saw the spitting image of Zuul, the Gatekeeper of Gozer—the demonic dog that appeared in Ghostbusters and haunted Sigourney Weaver’s fridge. “David and I batted around some ideas and I half-jokingly threw up Zuul,” says Arbour. “He loved it immediately.” And for the species name, they went for “crurivastator,” from the Latin words for “destroyer of shins.” “I had really wanted to use that for a long time and I was saving it for a specimen with a really well preserved tail,” says Arbour. “I wasn’t going to get a better choice than with this fellow.”

(Danielle Dufault / Royal Ontario Museum)

Arbour has been studying ankylosaurs for a decade, and in one of her first studies, she showed that they could indeed destroy shins. By using medical scanners to create three-dimensional computer models of the tail clubs, and putting these through digital crash-tests, she showed that they are formidable weapons. The tails were sturdy enough to swing the clubs, and the largest knobs would have hit with enough force to break bone.