Steven Jasinski, a doctoral candidate at the University of Pennsylvania, and curator of paleontology and geology at the State Museum of Pennsylvania, was reviewing the museum's collection when he found a fossil that caught his eye.
"As soon as I looked at the specimen, I could tell it was not the dinosaur it was thought to have been," Jasinski said.
The fossil was originally believed to be Saurornitholestes langstoni, a species within the Dromaeosauridae family.
This suggests the dinosaur had a sharp sense of smell, 'Live Science' reported.
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The researchers said the dinosaur's acute nose likely helped it to be a competitive predator, potentially by allowing it to hunt at night.
Jasinski compared the fossil to other dromaeosaurs using holotype specimens, which essentially act as the dictionary definition of a species.
He compared the skull fragment to available samples in the US, Canada, Mongolia, China, and Europe, but his fossil remained unique.
This gave Jasinski reasonable grounds to declare that he had found something entirely new: Saurornitholestes sullivani.