By Sean Willett
University of Calgary researchers have found new evidence of feathered dinosaurs in Alberta’s badlands. The research is being conducted at the Royal Tyrell Museum and sheds light on the evolution of dinosaurs and birds.
Although many dinosaurs were covered in feathers, paleontologists’ understanding of this phenomenon has been hindered by the rarity of feather traces in fossils. However, new research published on feathered dinosaur fossils in southern Alberta may mean that these remains are more common than previously thought. U of C paleontologist and researcher Darla Zelenitsky said that the discovery of feather traces in Albertan fossil beds is as unexpected as it is exciting.
“Feathered dinosaurs have only previously been found in ancient lake and lagoon deposits in northern China and Germany and it was thought that special conditions were required to actually preserve traces of feathers,” said Zelenitsky. “But the environments we found these dinosaurs preserved in are very different from that.”
The fossils in question belong to one juvenile and two adult specimens of Ornithomimus edmonticus, an ostrich-like dinosaur that belonged to the therapod class of dinosaurs. Therapods were a group comprised mainly of predatory dinosaurs such as Tyrannosaurus rex and Velociraptor mongoliensis and are the direct ancestors of modern birds. The feathered Ornithomimus specimens were found in riverbed sandstone deposits, which are fairly common fossil formations.
“These discoveries open up a great new potential to find feathered dinosaur specimens worldwide,” said Zelenitsky.
These feathers were found on the most primitive example of wing-like structures found in a dinosaur. These structures, known as pennibrachia, were only present in adult individuals — they were most likely used for courtship and mating, not for flight. This implies that wings evolved for the purpose of display and were then adapted for flight, instead of the other way around as was previously thought, said Zelenitsky.
“This is the most basal occurrence of wing-like structures in the dinosaurs leading to birds, so this gives us insights as to why these structures originally evolved,” said Zelenitsky.
While the concept of dinosaurs having feathers is not a new one, the fossil evidence to support this idea is recent. The fossil record of feather traces is still incomplete, meaning that the U of C’s research on Ornithomimus edmonticus will be a major addition to paleontologists’ growing understanding of dinosaur evolution.
With this recent discovery, the theory that most dinosaurs were covered in feathers, rather than just a select few, will continue to gain traction.
“Feathers were almost definitely on most therapods, and they could be more widespread in other dinosaurs as well,” said Zelenitsky. “We have filled in a gap in the fossil record of feathers in therapods, but there is a lot more yet to be found in terms of skin structure in dinosaurs.”