The fossils of a Daspletosaurus torosus were found in The Canadian Museum of Nature. It has been suggested that Daspletosaurus is a direct ancestor to Tyrannosaurus. The massive, stocky construct of the two tyrannosaurus and certain similarities in skull structures seem to be indicators of a close phylogenetic relationship between the two genera. Some have even gone further to suggest that Daspletosaurus is in fact a species of Tyrannosaurus (Daspletosaurus torosus = Tyrannosaurus torosus), but this has not been universally acknowledged. Currently, one species of Daspletosaurus, D. torosus, (torosus = "brawny") has been officially documented.
However, a recent tyrannosaur find in Montana is thought to be that of a new (still un-named) daspletosaur species.The skull of this find seems to point to a more "Tyrannosaurus-like" animal than D. torosus, possibly indicating an middle form between D. torosus and T. rex. Most of the specimens found were in Alberta, others were also establish in New Mexico.