Of all western North America’s fossiliferous lands, the Hell Creek Formation is among the richest boneyards. The 68-66 million year old exposures that stretch from Wyoming through Montana and the Dakotas have yielded countless dinosaurs, including the Cretaceous celebrities Edmontosaurus, Triceratops, and Tyrannosaurus. So much has been found that the chances of finding new, large dinosaurs are relatively slim, and many paleontologists have shifted their focus to investigating the biology of the formation’s abundant dinosaurs. Yet the Hell Creek isn’t totally tapped out yet. A bizarre dinosaur announced just this week shows that the famous formation still holds secrets.

Described by paleontologists Matt Lamanna, Hans-Dieter Sues, Emma Schachner, and Tyler Lyson in PLoS One, the new dinosaur is officially named Anzu