Acheroraptor temertyorum

Acheroraptor is an extinct genus of dromaeosaurid theropod dinosaur that lived in present-day Montana in the United States during the Maastrichtian stage of the Late Cretaceous period. It was described by Canadian paleontologists David Evans, Derek Larson, and Philip J. Currie in 2013. The genus contains a single species, A. temertyorum, named on an isolated maxilla with teeth. An incomplete dentary found nearby was also assigned to the species. These fossils were initially discovered by fossil poachers, though they were later sold to the Royal Ontario Museum, in layers belonging to the Hell Creek Formation. This indicates that these fossils date to the upper Maastrichtian stage, 67.2-66 million years ago. Acheroraptor is one of several dinosaurs known from the Hell Creek Formation, however it is the only named definitive dromaeosaurid.