 Cladistic analyses of tyrannosaurid phylogeny often find Tarbosaurus and Tyrannosaurus to be sister taxa , with Daspletosaurus more basal than either . A close relationship between Tarbosaurus and Tyrannosaurus is supported by numerous skull features , including the pattern of sutures between certain bones , the presence of a crescent @-@ shaped crest on the postorbital bone behind each eye , and a very deep maxilla with a noticeable downward curve on the lower edge , among others . An alternative hypothesis was presented in a 2003 study by Phil Currie and colleagues , which found weak support for Daspletosaurus as a basal member of a clade also including Tarbosaurus and Alioramus , both from Asia , based on the absence of a bony prong connecting the nasal and lacrimal bones . Alioramus was found to be the closest relative of Tarbosaurus in this study , based on a similar pattern of stress distribution in the skull . 
