A team of scientists led by an alumnus from the University of Kansas has found a fossil of the largest known raptor species in the Hell Creek Formation in South Dakota. According to a report from Phys.org, the species was believed to be roughly 17 feet in length, and was covered in feathers. The researchers named the fossil Dakotaraptor.

According to KU Paleontologist and study co-author David Burnham, “This new predatory dinosaur also fills the body size gap between smaller Theropods and large tyrannosaurs that lived at this time.”

The study was led by Robert DePalma, the curator of vertebrate paleontology at the Palm Beach Museum of Natural History. He led his team to South Dakota as a graduate student studying under KU paleontology professor Larry Martin, who passed away in 2014.

The raptor lived in the Cretaceous period, and was probably extremely light and agile like its smaller Theropod cousins, like the Velociraptor. Both fossils had evidence of “quill knobs,” or places where feathers likely attached to the forearms of the dinosaur.

Despite the Dakotaraptor’s feathers, it was more likely than not flightless. It is probably a distant ancestor of some bird species, who developed the ability to fly millions of years after it roamed the earth.

The research was published in the October 30 edition of the journal Paleontological Contributions, and a brief excerpt can be found here.

“Most dromaeosaurids were small- to medium-sized cursorial, scansorial, and arboreal, sometimes volant predators, but a comparatively small percentage grew to gigantic proportions. Only two such giant “raptors” have been described from North America. Here, we describe a new giant dromaeosaurid, Dakotaraptor steini gen. et sp. nov., from the Hell Creek Formation of South Dakota. The discovery represents the first giant dromaeosaur from the Hell Creek Formation, and the most recent in the fossil record worldwide. A row of prominent ulnar papilli or “quill knobs” on the ulna is our first clear evidence for feather quills on a large dromaeosaurid forearm and impacts evolutionary reconstructions and functional morphology of such derived, typically flight-related features. The presence of this new predator expands our record of theropod diversity in latest Cretaceous Laramidia, and radically changes paleoecological reconstructions of the Hell Creek Formation.”