Nanotyrannus

Nanotyrannus (/ˈnænoʊˌtaɪˌrænəs, -tɪ- /, ) is a genus of tyrannosauroid dinosaur that lived in what is now western North America during the Maastrichtian age of the Late Cretaceous, . Its fossils are known from the Hell Creek Formation. It was one of the last-known non-avian dinosaurs and lived until the Cretaceous–Paleogene extinction event. The first named species, N. lancensis, was described as a new species of Gorgosaurus in 1946 by Charles W. Gilmore based on a single skull. Re-examination of the specimen in 1988 by Robert T. Bakker, Michael Williams and Philip J. Currie moved the species