About 110 million years ago, the plant-eating dinosaur's body spanned beyond the length of a modern-day pickup, its back bore fearsome horns, and its ginger-colored skin camouflaged it from predators.
For the paper, an international team of researchers analyzed fossilized remains of B. markmitchelli that were fortuitously unearthed in northern Alberta, Canada, in March 2011.
Shawn Funk, a machine operator at an oil sands mine, dug into rock that felt unusual in texture and appeared odd in color.
After taking a closer look, the operator alerted his supervisor to the rare discovery: a surprisingly well-preserved armored dinosaur specimen, with horns and soft tissue intact, said Caleb Brown, a postdoctoral fellow at the Royal Tyrrell Museum of Paleontology in Alberta and lead author of the new paper.
The miners reported the discovery to the Royal Tyrrell Museum of Paleontology, where the incredibly lifelike fossil specimen is now on display
"What makes this particular specimen unique is that we don't just have the skeleton, we have all of the skin preserved, and that skin is not flattened or rotted away. It's actually preserved in the same form that it would have been when the animal was alive," Brown said.
"So the end result is, you don't really need to use your imagination much to figure out what this animal looked like," he said. "In that sense, in terms of reflecting what the animal looked like, it's probably the best in the world, and it's the closest you'll ever get to coming face-to-face with a dinosaur."
About a month after the fossils were found, Mark Mitchell, the technician at the museum for whom the new dinosaur is named, started to prepare the remains for research and display.
The preparation process took about five years. As rock was slowly chipped away, a fossilized dinosaur that Mitchell described as "very wide" and "very fat" emerged.
"Unfortunately, we didn't get the tail, but we have pretty much the pelvis forward, a bit of the hind foot and front limbs, (and) this guy is actually armored down his arms as well," Mitchell said, adding that the dinosaur has a large, spear-like spine sticking out of its shoulder.
"It's really cool," he said, to have a dinosaur as his namesake. "I've been into dinosaurs since I was 5 years old, so it's a dream come true."
'A really scary time to live in'
Once the fossils were cleaned and prepared for study, the researchers conducted a computed tomography, or CT, scan of the skull.
The researchers also analyzed the pattern and shape of the dinosaur's scales and armor, and conducted a chemical analysis of the organic compounds in the preserved skin samples.
Based on the melanin pigment in the samples, the researchers determined that the dinosaur's skin had reddish-brown patterns that could have offered it camouflage from predators. They found that the underbelly may have appeared lighter in color, possibly a protective coloration called countershading
"Midway on the side of the body, you have this transition from the light underside to the dark upside, and that's really interesting, because countershading is a type of camouflage, and you see that widely in the animal kingdom," said Jakob Vinther, a senior lecturer at the University of Bristol's School of Earth Sciences in England and a co-author of the new paper.
"The fact that we have this 1.3-metric-ton dinosaur that is armored and it has on top of that camouflage just demonstrates that the Cretaceous period
was a really scary time to live in," Vinther said.
What could have been ferocious enough to chow down on B. markmitchelli? Those two-legged meat-eating dinosaurs known as theropods, he said.
"There was, in North America, a large theropod called Acrocanthosaurus
, and that is the likely culprit that could potentially be eating these guys," Vinther said.
"No matter whether you were big or small, theropods were making your life miserable," he said. "Even if you were a giant armored dinosaur, you had to have some additional concealment strategies to not stick out in the environment, to enhance your chances to survive."
B. markmitchelli represents not only a new species of armored dinosaur but a new genus of dinosaur called Borealopelta, according to the new paper.
Though it may appear similar to Ankylosaurus, another genus of armored dinosaur, Borealopelta remains distinctive in its features as well as the time period in which it lived, Brown said.
A step forward in digging up dinosaur secrets
Though any analysis of a newfound dinosaur can be up for debate, the new research appears strong in its approach and conclusions, said Jack Horner, a professor of paleontology at Montana State University who was not involved in the new paper.
"I think this is the best, most comprehensive paper concerning dinosaurs that I've seen in the past few years," said Horner, who served as the paleontology consultant on the "Jurassic Park" and "Jurassic World" films.
"I don't know much about Ankylosaurus, but I do know that the sediment from which the specimen was excavated represents a much different environment than the formations that these animals generally come from, so it's reasonable that it's a different genus and species," he said.
Brown, lead author of the new paper, said that he hopes this new description of B. markmitchelli can reignite a sense of excitement and confidence around dinosaur paleontology.
"We've known what dinosaurs have looked like for many decades, and as we find out more about these animals, our picture keeps changing, but it gets more accurate every time we add to the evidence," Brown said.
"Finding this specimen so well-preserved was actually a nice internal check, because in terms of the shape of the animal, in terms of the skin, in terms of the proportion, it's pretty much exactly what we would have thought," he said. "So, that's a nice internal check for us as scientists. ... We're doing a pretty good job figuring out what these animals look like."