 By the late Maastrichtian , albertosaurines appear to have gone extinct , while the tyrannosaurine Tyrannosaurus roamed from Saskatchewan to Texas . This pattern is mirrored in other North American dinosaur taxa . During the Campanian and early Maastrichtian , lambeosaurine hadrosaurs and centrosaurine ceratopsians are common in the northwest , while hadrosaurines and chasmosaurines were more common to the south . By the end of the Cretaceous , centrosaurines are unknown and lambeosaurines are rare , while hadrosaurines and chasmosaurines were common throughout the Western Interior . A study published in the journal Scientific Reports on February 2 , 2016 by Steve Brusatte , Thomas Carr et al. indicates that during the later Maastrichtian , Tyrannosaurus itself might have been partially responsible for the extinction of the other tyrannosaurids in most of western North America . The study indicates that Tyrannosaurus might have been an immigrant from Asia as opposed to having evolved in North America ( possibly a descendent of the closely related Tarbosaurus ) that supplanted and outcompeted other tyrannosaurids . This theory is further supported by the fact that few to no other types of tyrannosaurid are found within Tyrannosaurus ' known range . 
