Another week, another feathery dinosaur. Since the discovery of the fluffy Sinosauropteryx in 1996, paleontologists have discovered direct evidence of fuzz, feather-like bristles and complex plumage on over two dozen dinosaur genera. I love it, and I’m especially excited about a discovery announced today. In the latest issue of Science, University of Calgary paleontologist Darla Zelenitsky adds another enfluffled species to the dinosaurian ranks. Even better, the specimens raise hopes that many more dinosaurs might be preserved with their feathery coats intact….
Even though paleontologists expected feathery Ornithomimus, the discovery was still a surprise. “I was in disbelief,” Zelenitsky said. “They’re the first feathered dinosaurs from the Americas, and the first ornithomimosaurs with feathers, as well. It was shocking to say the least.” But there’s more to the find than simply adding another species of fluffy dinosaurs to the list. The fact that the adult and juvenile animals had different kinds of plumage adds new evidence that coelurosaurs changed their fluffy coats as they aged. “The one juvenile was completely covered in filamentous type feathers,” Zelenitsky said. What the adults looked like comes from the two other specimens. One adult skeleton, lacking forearms, preserves fuzzy feathers, and “the second adult had markings on the forearm.” Together, the specimens indicate that adult Ornithomimus were mostly covered in fuzz but developed more complex arm feathers by adulthood. Sex is probably behind the plumage change. “We infer that because these wing feathers are not showing up until later in life, they were used for reproductive purposes,” Zelenitsky said. Perhaps adult Ornithomimus used flashy arm feathers to strut their stuff in front of potential mates.