Borealopelta markmitchelli reappeared in the light in 2017, millions of years after it vanished. The dinosaur is so well preserved that we can see how it looked in life.
The whole skin, including the armor that protects it, the spikes along its sides, the majority of its body and feet, and even its face, survived evolutionary divergence. Paleontologists are trying to figure out what killed it, how it ended up at the bottom of a prehistoric sea, and how it was preserved so well.
Shawn Funk, a shovel operator at Suncor Energy’s Millennium oilsands mine north of Fort McMurray, Alta., was working away at a large bank in March 2011 when he uncovered Alberta’s oldest dinosaur fossil and one of the best-preserved dinosaur fossils ever unearthed.
Six years after its discovery, the strange dino was recognized as a new species and given a scientific name: Borealopelta markmitchelli. The name “Borealopelta” means “North Shield,” and it is a tribute to Mark Mitchell, the Royal Tyrrell Museum technician who spent 7,000 hours working for every millimeter while removing the dinosaur from the rock it was discovered in.
“During preparation, I would fit together the blocks like a puzzle, and the animal started to really take shape,” Mitchell explained in a new interview with Ars Technica.
“Right before Christmas one year,” he continued, “I had pieced together both sides of the neck and the head, and you could really appreciate the impressiveness of the specimen and that this was a living creature with astounding preservation.”
The five-and-a-half-meter-long specimen was so well preserved that researchers could peek into the eyes of a real dinosaur from a time when North America was different.
Borealopelta was formed like a tank and clad in solid armor, particularly around its neck, indicating that it needed predator protection.
Acrocanthosaurus was the fearsome dinosaur of the day 110 million years ago, a killing machine that ruled the Cretaceous long before more well-known predators like T. rex arrived.
According to the museum’s curator Donald Henderson, it was a “one in a billion” discovery.
After Mitchell had finished creating the incredible specimen, specialists meticulously researched it. One such investigation was led by Royal Tyrell curator Caleb Brown and focused on the ankylosaur’s osteoderms, which typically move out of place in specimens that aren’t securely preserved. In this case, however, these remained where they belonged, and Brown counted all 172.
“Many armored dinosaur skeletons are preserved disarticulated, meaning their bones are all jumbled up,” Brown told Ars. “Having the osteoderms preserved in life position in this specimen and other specimens can give us clues as to how to reconstruct those specimens where the position of the armor is less clear.”
Additionally, Brown and his colleagues hypothesize that the Boreapelta utilized countershading, a camouflage that has never been observed in a creature of its size.
According to Ars, the fact that a dinosaur with such heavy armor needed a cloak to survive could indicate that the Cretaceous era was far harsher than initially believed.
The nodosaur spent 110 million years in this natural time capsule until one fateful day when this remarkable species and the mysteries of Borealopelta were revealed.