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
Raptorex other fauna we recovered from the rock matrix alongside the "Raptorex" fossil, we could generally pinpoint where it had been dug up in an area along the border with Inner Mongolia." However, only a single fish vertebra and a crushed, unidentifiable mollusk shell were actually present alongside the "Raptorex" specimen. Sereno and colleagues identified the fish vertebra as being similar to the genus "Lycoptera", a key index fossil of the early Cretaceous Yixian formation. However, they did not describe the bone or note any features in common with known "Lycoptera" specimens. Sereno's interpretation of the specimen as an early, primitive,