Raptorex Raptorex Raptorex is a dubious genus of tyrannosaurid dinosaur. Its fossil remains consist of a single juvenile specimen probably uncovered in Mongolia, or possibly northeastern China. The type species is "R. kriegsteini", described in 2009 by Sereno and colleagues. The genus name is derived from Latin ', "robber", and ', "king". The specific name honours Roman Kriegstein, a survivor of the Holocaust, whose son Henry Kriegstein donated the specimen to the University of Chicago for scientific study. While initially considered to have come from the Yixian Formation of China, dated to approximately 125 million years ago during the early Cretaceous
Specimens of Tyrannosaurus paper under the name "Dynamosaurus imperiosus". At the time of their initial description and naming, these specimens had not been fully prepared and the type specimen of "T. rex" had not even been fully recovered. In 1906, after further preparation and examination, Henry Fairfield Osborn recognized both skeletons as belonging to the same species. Because the name "Tyrannosaurus rex" had appeared just one page earlier than "Dynamosaurus" in Osborn's 1905 work, it was considered the older name and has been used since. Had it not been for page order, "Dynamosaurus" would have become the official name. The first named fossil