Ostrichlike Dinosaur Covered in Fossilized Feathers

The skeleton of a heavily feathered, ostrichlike dinosaur has "unparalleled" fossilized feathers and skin — anatomical features that aren't usually preserved in dinosaur remains, a new study reports.

The remains indicate that the dinosaur — an Ornithomimus, a fast-moving theropod (bipedal, mostly meat-eating dinosaurs) with an uncanny resemblance to an ostrich — sported a feathery coat during the Late Cretaceous, more than 66 million years ago.

Study lead researcher Aaron van der Reest found the partial skeleton in Alberta's Dinosaur Provincial Park in 2009, during his first undergraduate year at the University of Alberta. The newfound skeleton is just one of three feathered Ornithomimus specimens in the world, and the only one with a well-preserved tail, he said.

"It's pretty remarkable. I don't know if I've stopped smiling since [excavating it]," van der Reest said in a statement. "We now know what the plumage looked like on the tail, and that from the midfemur down, it had bare skin."

Modern ostriches also have exposed bare skin, which they use to regulate their body temperature, the researchers said in the study. Given that the newfound Ornithomimus specimen has a lightly feathered neck and doesn't have feathers on its legs or the underside of its tail, perhaps it, too, used its bare skin for thermoregulation, they said.

"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," van der Reest said.

In fact, the fossilized feathers were crushed because of the weight of the sediment over them, but a scanning electron microscope revealed a 3D keratin structure of feathers on the dinosaur's tail and body.

"We are getting the newest information on what these animals may have looked like, how they maintained body temperatures and the stages of feather evolution," van der Reest said.

In addition, it provides more evidence that birds evolved from theropod dinosaurs.

"There are so many components of the morphology of this fossil as well as the chemistry of the feathers that are essentially indistinguishable from modern birds," said study co-researcher Alex Wolfe, an adjunct professor of paleobiology at the University of Alberta.

Read more at Discovery News