An ornithomimus specimen discovered by an undergraduate student from the University of Alberta is being called the most complete feathered dinosaur specimen found to date in North America, and it may shed new light on the origins of feathers in dinosaurs and early birds.
According to Gizmodo, the 75 million year old fossil was unearthed by paleontologist Aaron J. van der Reest in the Upper Cretaceous Dinosaur Park Formation in Alberta, and is the first non-avian dinosaur specimen to include traces of preserved skin from the abdomen to the femur.
Van der Reest’s analysis of the remains, which he detailed in the latest edition of the scientific journal Cretaceous Research, revealed that the bodies of the ornithomimus were not completely covered by feathers. Instead, these 6 1/2 foot tall omivorous bipeds would have had bare legs.
“From the mid-femur down, it had bare skin,” the author said in a statement. “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.”
Ornithomimus is just one of three to be found with feathers
While working on an undergraduate project, van der Reest was put in charge of excavating and preparing a large fossil that had been at the university since 2009, the Globe and Mail said. The fossil was still entombed in rock and had been deemed low-priority because its forelimbs and its head were clearly missing.
The paleontologist told the newspaper that he started working in the tail region, and 20 minutes later, he stumbled across a black area that turned out to be feathers. It took van der Reest two years to fully uncover the ornithomimus specimen, and while this dinosaur was known from previous research, the new specimen is far better preserved than any previous ones.
Furthermore, van der Reest’s specimen is one of just three showing signs of feathers, and thanks to the relatively undisturbed nature of the river bed where it was originally discovered, he and his colleagues were able to study the feathers in incredible detail.
Birds and ornithomimus are believed to have evolved from different lines of dinosaurs, and the new discovery suggests that many features found in modern bird feathers originally evolved in an ancestor common to both types of creatures. When studied in combination with other fossils from the same era, the find could help explain how and why feathers first emerged.
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Feature Image: A. J. Reest et al., 2015
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