Growing up in Havre, in Northern Montana, and then working a cattle ranch with her husband for 62 years, Carol Chagnon gave little thought to the idea that dinosaurs once roamed what is now her backyard.
When her sons were younger they would hike the hills and find buffalo bones — another species now gone from the area — but she never gave dinosaurs much consideration.
Now a fantastically preserved, 75 million-year-old plant-eater named Zuul — discovered over the hill from Chagnon’s house in 2014 — has gone on display in Toronto’s Royal Museum of Ontario in a special exhibit. It’s been described as the most complete skeleton of its kind ever found.
“Zuul is really special,” said David Evans in a telephone interview. He’s the museum’s paleontologist and co-curator of the exhibit “Zuul: Life of an Armoured Dinosaur.”
The place where the dinosaur was found doesn’t look spectacular, but the badlands hillside has turned out to be very unusual.
“It’s about the size of a football field, and over 100 feet deep,” Evans said. “It’s one of the biggest dinosaur quarries I’ve ever seen.”
The Ankylosaurus gets its name from the 1984 “Ghostbusters” movie in which the demonic-looking beast named Zuul possesses the character played by actress Sigourney Weaver.
Identified by paleontologists as a new species, what sets the Ankylosaur apart is how exquisitely it was preserved and how much of it was unearthed. From its ridged head, across its rough and tough hide covered with osteoderms — bony deposits that form scales and plates somewhat like those found on a crocodile’s back — on down to its spiked and club-like tail, Zuul’s body has been removed from the earth largely intact. Even portions of its skin were fossilized.
Ankylosaurs are rare in the fossil record, Evans explained, accounting for only about 5 percent of dinosaurs ever found. None are as complete as Zuul, nor do they preserve the armor plates — ranging from pea size to as big as a dinner plate — in the positions they occupied when the dinosaur was alive.
“They were quite adorned,” Evans said. “It gives us an amazing view of what these dinosaurs would have looked like,” he said.
Beauty of the beast
When alive, Zuul would have weighed about 2.5 tons — a bit more than a rhinoceros — and stretched to 20 feet from the tip of its nose to its weaponized tail. The tail club could have served a dual purpose: crushing the ankles and shins of threatening predators like Tyrannosaurus rex, and serving as a dueling object when fighting for mates with others of its own kind.
Built low to the ground, flat and wide like an ancient Humvee, the dinosaur had four horns on its head, one behind and under each eye. It even had armored eyelid covers. The horns and design of its skull helped paleontologists identify it as different from similar dinosaur discoveries.
The area where Zuul was discovered is part of the Judith River Formation, a layer of sandstone that extends down from Canada to just north of Lewistown, in Central Montana. That’s the same geologic formation that in 2000 produced Leonardo, a 77-million-year-old duckbilled dinosaur found west of Malta in Northern Montana and is so well preserved it has been called mummified.
Finding dinosaur fossils in the Judith formation has been difficult, but those found tend to be special, Evans said. Zuul was buried 30 to 40 feet into a hillside and about 40 to 50 feet deep. That helped preserve the fossil, since it wasn’t weathered, frozen and thawed, or broken by plant roots, Evans pointed out.
Back when Zuul ruled, large portions of Eastern Montana would have been under water, part of a shallow inland sea that cut North America in half from Canada to Mexico. Zuul was quickly buried in a flood of a small freshwater river’s back channel along a floodplain crisscrossed and braided by several similar streams, Evans said.
It may have taken about four floods to completely bury Zuul, in that time a meat-eater could have dined on its legs — the only missing parts of the fossilized animal. Flipped onto its back by the water, Zuul was quickly buried in the sand, feet up, allowing for excellent preservation of its armored back.
The quarry where Zuul was found has a spectacular assemblage of other fossils, as well. Fossilized plants are giving paleontologists a better understanding of what the environment was like.
“It’s an incredible window into what the world was like 75 million years ago in Montana,” Evans said. “I’ve been working in that area 15 years and we’ve found nothing like the quality of that specimen. We haven’t even found a complete turtle shell, and there’s 10 of them with Zuul.”
Once Zuul is free — a painstakingly slow process expected to be completed by the end of January — Chagnon plans to travel 1,700 miles to Toronto, Canada, and see the creature that once lay trapped in sandstone so close to her badlands ranch along the Milk River.
“It’s going to be quite impressive,” she said.