sister taxon to Daspletosaurus, follow by Alioramus. There was an alternative hypothesis from Phil Currie and colleagues (2003) who suggested Daspletosaurus to be more closely related to Tarbosaurus and Alioramus than to Tyrannosaurus based on cranial features. This relationship, however, has not been found in more recent studies. In 1988 Gregory Paul considered all tyrannosaurines at the time except Alioramus to be species of Tyrannosaurus. In the second edition of The Princeton Field Guide to Dinosaurs published in 2016, Paul would continue this thought as well as including Bistahieversor, Teratophoneus, Lythronax, and Nanuqsaurus into the genus as well. This multispecies Tyrannosaurus classification is, however, not widely accepted by most paleontologists. In some phylogenetic studies Bistahieversor is nested within Tyrannosaurinae, but it is most often recovered as the sister taxon to Tyrannosauridae instead. As of 2021, there are at least three lineages of tyrannosaurines. The basal most clade is the Alioramini, the second clade to diverge is an unnamed clade comprising the American southwest taxa Dynamoterror, Lythronax, and Teratophoneus. They are sister to a clade comprising Nanuqsaurus, Daspletosaurini and unnamed clade which includes Zhuchengtyrannus, Tarbosaurus, and Tyrannosaurus. The cladogram below is the result of the phylogenetic analysis performed by Voris et al. (2020): References Tyrannosaurids Dinosaurs of North America Cretaceous dinosaurs