A fossil site in Canada has yielded the best-preserved specimen of the dromaeosaurid dinosaur Saurornitholestes langstoni ever found.
It lived approximately 76 million years ago (Cretaceous period) in what is now North America.
The species was previously known from fragmentary remains and was long thought to be so closely related to Velociraptor from Mongolia that some paleontologists called it Velociraptor langstoni.
The specimen was remarkably complete and exquisitely preserved, with all the bones (except for the tail) preserved in life position.
“Because of their small size and delicate bones, small meat-eating dinosaur skeletons are exceptionally rare in the fossil record,” said Dr. David Evans, a researcher in the Department of Natural History at the Royal Ontario Museum and the Department of Ecology Evolutionary Biology at the University of Toronto.
“The new skeleton is by far the most complete and best-preserved raptor skeleton ever found in North America. It’s a scientific goldmine.”
Dr. Evans and his colleague, University of Alberta’s Professor Philip Currie, analyzed the new specimen and found that Saurornitholestes langstoni had a shorter and deeper skull than Velociraptor.
At the front of the skull’s mouth, they also discovered a flat tooth with long ridges, which was likely used for preening feathers. The same tooth has since been identified in Velociraptor and other dromaeosaurids.
The team also established a distinction between dromaeosaurids in North America and Asia.
“The new anatomical information we have clearly shows that the North American dromaeosaurids are a separate lineage from the Asian dromaeosaurids, although they do have a common ancestor,” Professor Currie said.
“This changes our understanding of intercontinental movements of these animals and ultimately will help us understand their evolution.”
The team’s paper was published in the journal Anatomical Record.
Philip J. Currie David C. Evans. Cranial Anatomy of New Specimens of Saurornitholestes langstoni (Dinosauria, Theropoda, Dromaeosauridae) from the Dinosaur Park Formation (Campanian) of Alberta. Anatomical Record, published online September 9, 2019; doi: 10.1002/ar.24241