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 to the same species. A conference was held at the Burpee museum in 2005, during which paleontologists debated whether these "pygmy tyrants" represented adult specimens of a small species, or juvenile specimens of "Tyrannosaurus rex". While there were a few dissenters, a majority of paleontologists at the conference decided on the latter, and that both Jane and "Nanotyrannus" were juvenile "T. rex". However, the Jane material has yet to be properly studied and described by scientists. Although Larson (2013) saw Jane as more identical to CMNH 7541 and LACM 28471 than to adult "T. rex" in having a higher tooth