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.”
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.
Zuul has an unusually flattened club and spikes running down its length of its tail. Its head, meanwhile, has distinctive peaks and pyramids over the eyes, and short horns projecting back from the skull. But it’s the presence of both head and tail that’s surprising: Zuul is the first ankylosaur in which both features are preserved. For some reason, most of these armored giants are missing either their front or back ends.
Arbour thinks that’s because they’re so bulky and heavy: As the animal decays, these elements snap off and roll away from the rest of the skeleton. It also seems that ankylosaurs were solitary animals, whose fossils are therefore harder to find than those of duck-billed hadrosaurs, or Triceratops and its horned kin. Whatever the reasons, a complete ankylosaur is reason for excitement.
“I’m so happy that the Royal Ontario Museum got it and it went to a good home, where it’ll be prepared properly,” says James Kirkland, a state paleontologist for the Utah Geological Survey, who was also contacted about the specimen. “With a specimen like that, if someone just wanted an impressive mounted skeleton, you’d lose a lot of the data. The keratin on the armor is fragile stuff.”
He’s talking about the animal’s skin. After its death, Zuul was partially mummified, so it still retains with many features that are extremely rare in dinosaur fossils, including bony scales called osteoderms, and impressions of the creature’s skin. There are even some dark films that might represent traces of protein like keratin. “It really helps us understand what Zuul looked like while it was alive,” says Arbour. “We want to do tests to see if we can find ancient molecules like keratin in its skin.”
Elsewhere in Canada, the paleontologists of the Royal Tyrrell Museum have also struck gold. In a tar-sand mine in Alberta, they uncovered a nodosaur—an ankylosaur with spines on its neck and shoulders, but no tail club. Like Zuul, it’s also beautifully preserved and partially mummified. “It’s a spectacular specimen,” says Kirkland. “It’s perfect. It’s pickled.”
Ankylosaurs “don’t have the same public popularity like tyrannosaurs or raptors,” says Arbour, “but I think interest is increasing.” She hopes that these new discoveries will help to spur that interest. Already, they’ve shown that the group was more successful and species-rich than people had thought. In the millions of years before an asteroid wiped out the majority of dinosaurs, they were flourishing, diversifying, and evolving fast—a dynasty of living tanks, destroying shins and taking names.
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