An undergraduate University of Alberta paleontology student has discovered an Ornithomimus dinosaur with preserved tail feathers and soft tissue. The discovery is shedding light on the convergent evolution of these dinosaurs with ostriches and emus relating to thermoregulation and is also tightening the linkages between dinosaurs and modern birds.
"We now know what the plumage looked like on the tail, and that from the mid-femur down, it had bare skin," says Aaron van der Reest. This is the first report of such preserved skin forming a web from the femoral shaft to the abdomen, never before seen in non-avian dinosaurs. "Ostriches use bare skin to thermoregulate. Because the plumage on this specimen is virtually identical to that of an ostrich, we can infer that Ornithomimus was likely doing the same thing, using feathered regions on their body to maintain body temperature. It would've looked a lot like an ostrich." In fact, this group of animals—referred to as ornithomimids—is commonly referred to as "ostrich mimics."
Although the preserved feathers are extremely crushed due to sediment compaction, scanning electron microscopy reveals a three-dimensional keratin structure to the feathers on the tail and body. van der Reest made the initial discovery during his first year as an undergraduate student, supervised by Philip Currie, Canada's leading palentologist."It's pretty remarkable. I don't know if I've stopped smiling since."