Discovered in the Hell Creek geological formation of Montana and the Dakotas, the 66-million-year-old fossils belonged to a fast-running, 500-pound, four-meter-long creature with a bony crest atop its head and five-inch claws at the end of feathered, wing-like forelimbs. Lamanna and his colleagues studied the bones for a decade, and finally arrived at a consensus on just what the creature probably looked like.
“These fossils are some of the most interesting new dinosaurs to come out of North America over the past decade,” Stephen Brusatte, a vertebrate palaeontologist at the University of Edinburgh who wasn’t involved with the study, told The Guardian. A. wyliei belongs to a group of dinosaurs called oviraptorosaurs that ranged in size from something akin to modern chickens to Gigantoraptor, which was twice as tall as the average human. The hell chicken was the one of the first representatives of the group, which is mostly known from fossils originating in Asia, to be found in North America. “Oviraptorosaurs are one of the most bizarre groups of dinosaurs to ever live. This new dinosaur, Anzu, looks like something that was placed in the Cretaceous by a Hollywood monster movie director,” Brusatte continued. “Looking at these animals, it’s hard to believe they were real.”