The dinosaur's armour and spiked tail with a club at the end would have helped it keep predators at bay. (Danielle Dufault/Royal Ontario Museum)

Scientists from the Royal Ontario Museum have recently discovered the fossil of a 75-million-year-old species of armoured dinosaur, or ankylosaur, which was unusually well-preserved — and oddly familiar to movie buffs.

Meet Zuul crurivastator — destroyer of shins — whose discovery is being discussed in the Royal Society Open Science journal.

The name was inspired by the Ghostbusters villain Zuul, says Victoria Arbour, paleontologist and postdoctoral fellow at the ROM and University of Toronto.

"Me and my co-author David Evans were batting around ideas for what to name it, and I just half-jokingly said, 'It looks like Zuul from Ghostbusters,'" she said. "Once we put that out there we couldn't not name it that."

Paleontologist Victoria Arbour noticed a resemblance between the skull of the dinosaur and Ghostbuster villain Zuul, and the name stuck. (Danielle Dufault/Royal Ontario Museum, Ghostbusters Wiki)

But there's much more to this discovery than a catchy name.

The plant-eating species has a short, rounded snout and prominent horns behind the eyes. A large knob of bone at the end of its stiffened tail could have been used to strike predators in the legs (hence the name destroyer of shins) or for battling others for territory or mates, the scientists said.

The tail is three metres long and covered in rows of large bony spikes, adding to its menace.

"I wanted to name something an ankle breaker because of these tail clubs," Arbour said. "But I wanted a specimen with a nicely preserved tail, and they don't get better than this particular specimen."

Finding a full dinosaur skeleton is a rare feat, she said, and is especially uncommon for this group of dinosaur.

"They were slightly more rare animals in their ecosystems compared to other dinosaurs we know from the same areas, such as the duck-billed dinosaur."

Nearly complete skeleton

It's also rare to find an ankylosaur skeleton well-preserved, because the armour is part of the skin, Arbour said, which would tend to get washed away from the skeleton.

With this discovery, scientists have the full skull, tail, body, armour and even some preserved soft tissue, she said.

"This is a really useful specimen, we can visualize what it looked like while it was alive, and it will also help with isolated bones [of other animals] and give us an idea of what we're looking at," Arbour said.

Paleontologists often find bone fragments from the armour of other ankylosaurs, she said, but without the full picture it's hard to determine what the bones are. This specimen will help in identification.

"It's kind of like a Rosetta stone in some ways."

The fossil was found in the Judith River Formation in Montana, just 25 kilometres south of the Alberta border, Arbour said. It was uncovered when a crew of private excavators bumped into the skeleton buried under metres of rock while unearthing a nearby tyrannosaurus.

"It would never have been exposed for thousands of years under rock erosion," she said, adding that the thickness of the rock is probably why the fossil is so well-preserved.

The discovery of the skeleton and the detailing of the skull and tail are just the beginning of what paleontologists will learn from the Zuul crurivastator, Arbour said.

The shape of the ankylosaur's skull helped researchers determined it was a new species — and also that it resembled the villain Zuul from Ghostbusters. (Brian Boyle/Royal Ontario Museum)

The specimen's body — ribs, belly and hips — are still encased in 15,000 kilograms of rock. There is soft tissue to try to glean ancient proteins from. Researchers will try to determine how it died and ended up beneath so much rock, she said.

"In the same quarry around the skeleton there were lots of other animals and plants that lived in the same environment as well. We'll be able to reconstruct the whole ecosystem," Arbour said. "This is just the beginning, but we're obviously very excited about it."