Borealopelta markmitchelli
Name: Borealopelta markmitchelli
Name Meaning: Northern Shield
Described By: Brown et al.
Classification: Dinosauria, Ornithischia, Genasauria, Thyreophora, Eurypoda, Ankylosauria, Nodosauridae, Nodosaurinae
Borealopelta is an exciting recently described Nodosaurid that is remarkable because it was essentially mummified - the osteoderms, skin, and even color were preserved in three-dimensions. The fossil was so heavy and so buried in its environment that it actually broke under its own weight, but luckily the pieces were kept and transported successfully. Borealopelta was found in the Clearwater Formation of Alberta, Canada, living about 110 to 112 million years ago, in the Albian age of the Early Cretaceous. Borealopelta had died on the shore of the Western Interior Seaway and was washed out to sea after death, buried on the ocean floor quickly (topside - down) with very little distortion, making the fossil look like how the dinosaur looked when it was alive.
Photo by Machairo, CC BY-SA 4.0
Borealopelta shows the positioning of armor when the animal was alive, a unique thing for an Ankylosaur which usually aren’t preserved articulated enough to know with this level of precision. In addition to that, the osteoderms had keratin sheaths over them, indicating the spikes and other structures were even longer in life than they were in typical ankylosaur fossils. In fact, this probably applies to most armor structures in dinosaurs, indicating that things like Triceratops had amazingly long horns. Since these structures - in both groups of dinosaurs - were primarily sexually selected ones (meaning, they got so ridiculous because other dinosaurs found them sexy), the sheathes wouldn’t have been really used for defense very much, though they would have been capable of doing so.
By Nobu Tamura, CC BY-SA 4.0
Borealopelta was preserved with pigmentation - a structure usually only found in things like small birdie dinosaurs (with Psittacosaurus as a notable excpetion) - indicating this dinosaur would have been reddish-brown colored, with countershading for camouflage in its environment, though it’s difficult to tell what sort of environment that would have been since the animal was washed out to sea. The armor on its back that wasn’t so extensively keratinized (ie, not the big shoulder spikes, but the bumpy osteoderms all over) probably would have allowed it to defend itself, since the camouflage indicates it would have been hunted by prey (why hide if nothing is chasing you?). This dinosaur was recently discovered, and hopefully more research of it will show us even more about Borealopelta and other Ankylosaurs.