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
Tyrannosaurus head was not as maneuverable as the skulls of allosauroids, due to flat joints of the neck vertebrae. One study of "Tyrannosaurus" specimens with tooth marks in the bones attributable to the same genus was presented as evidence of cannibalism. Tooth marks in the humerus, foot bones and metatarsals, may indicate opportunistic scavenging, rather than wounds caused by combat with another "T. rex". Other tyrannosaurids may have practiced cannibalism. Suggesting that "Tyrannosaurus" may have been pack animals, Philip J. Currie compared "T. rex" to related species "Tarbosaurus bataar" and "Albertosaurus sarcophagus", citing fossil evidence that may indicate pack behavior. A