Decoding the Dinosaur Mummy: What Borealopelta markmitchelli Reveals About Armored Dinosaurs

About 110 million years ago in what’s now Alberta, Canada, a dinosaur resembling a 2,800-pound pineapple ended up dead in a river. Today, that dinosaur is one of the best fossils of its kind ever found—and now, it has a name: Borealopelta markmitchelli, a plant-eating, armored dinosaur called a nodosaur that lived during the Cretaceous period. After death, its carcass ended up back-first on the muddy floor of an ancient seaway, where its front half was preserved in 3-D with extraordinary detail.

Unearthed by accident in 2011 and unveiled at Alberta’s Royal Tyrrell Museum in May, the fossil immediately offered the world an unprecedented glimpse into the anatomy and life of armored dinosaurs. “It’s a beautiful specimen,” says Victoria Arbour, a postdoctoral researcher at the Royal Ontario Museum who is studying another well-preserved armored dinosaur called Zuul crurivastator. “It’s great to have specimens like this one and Zuul that give us an idea of what these dinosaurs looked like when they were alive.”

Uncovering the Secrets of Borealopelta markmitchelli

It’s been a long road for Borealopelta. The creature’s subterranean isolation came to an end on March 21, 2011, when heavy-equipment operator Shawn Funk stumbled on the fossil in an oil sands mine in northern Alberta operated by energy company Suncor. The fossil then traveled to the Royal Tyrrell Museum’s preparation lab, where technician Mark Mitchell painstakingly chipped away the surrounding rock—a feat that took him more than 7,000 hours over nearly six years. The skull alone took some eight months to extricate.

“Were it not for his commitment, [Borealopelta] probably would have never come to light,” says Caleb Brown, a postdoctoral researcher at the Royal Tyrrell Museum and the new study’s lead author. “It’s an extreme amount of effort. The preparators are often the unsung heroes.”

In addition to announcing its name, the first scientific description of the nodosaur, published today in the journal Current Biology, is revealing even more of its secrets. “We knew six years ago that this was going to be special,” says Don Henderson, the Royal Tyrrell Museum’s curator of dinosaurs. “I don’t think we realized how special it was.”

The Significance of Borealopelta markmitchelli

All the work has been matched with an extraordinary honor. The new study confirms that the dinosaur represents a newfound genus and species, and its formal name translates to “Mark Mitchell’s northern shield”—a nod to the fossil’s liberator, its impeccably preserved armor, and the location where it had been entombed.

“I was very excited [when I found out its name],” says Mitchell.

“I put my hands up in the air and cheered.”

The study’s most provocative claim involves the nodosaur’s potential coloration, which the study authors say is preserved in a blackish coating that covers much of the dinosaur’s exterior. Within these films—thought to be remnants of the dinosaur’s skin—study coauthor and University of Bristol paleobiologist Jakob Vinther says that he has found chemical hints of the red-brown pigment pheomelanin. Importantly, Vinther and his colleagues didn’t find signs of the pigment everywhere on the animal. After sampling along cross-sections of the fossil, Vinther says that its underbelly appears to have lacked pheomelanin, which would have made that part of the animal lighter in color.

While some animals have dark backs and light bellies to help regulate body temperature, others have the patterning as a form of camouflage called countershading. This two-tone look flattens an animal’s appearance from afar and makes it harder for predators to spot. In modern ecosystems, land mammals with body masses more than about a ton, such as rhinoceroses, don’t need this kind of visual defense strategy to keep predators at bay. By contrast, if the hefty and well-armored Borealopelta needed countershading, its predators must have been terrifyingly effective.

The discovery and study of the Borealopelta markmitchelli fossil have been a remarkable journey, shedding light on the anatomy and life of these ancient armored dinosaurs. The meticulous work of Mark Mitchell and the dedicated researchers has allowed us to gain an unprecedented glimpse into the past, adding to our understanding of these fascinating creatures that roamed the Earth millions of years ago. The Borealopelta markmitchelli is a remarkable testament to the wonders of paleontology and the dedication of those who uncover the secrets of the past.