The Canadian specimen literally defies words, in more ways than one. As this article went to press, museum staff were finalizing the creature’s scientific description and hadn’t yet settled on a common name for it. (“Mrs. Prickley,” a reference to a Canadian sketch comedy character, didn’t stick.) But already the fossil is providing new insights into the structure of nodosaurs’ armor. Reconstructing armor usually requires educated guesswork, as the bony plates, called osteoderms, scatter early in the decaying process. Not only did the osteoderms on this nodosaur preserve in place, but so did traces of the scales in between.
What’s more, sheaths once made of keratin—the same material that’s in human fingernails—still coat many of the osteoderms, letting paleontologists see precisely how these sheaths exaggerated the armor’s size and shape. “I’ve been calling this one the Rosetta stone for armor,” says Donald Henderson, curator of dinosaurs at the Royal Tyrrell Museum.
Details & more pics: http://www.nationalgeographic.com/magazine/2017/06/dinosaur-nodosaur-fossil-discovery/