In the late Campanian of North America, Daspletosaurus was a contemporary of the albertosaurine tyrannosaurid Gorgosaurus.
This is one of the few examples of two tyrannosaur genera coexisting.
In modern predator guilds, similar-sized predators are separated into different ecological niches by anatomical, behavioral or geographical differences that limit competition.
Several studies have attempted to explain niche differentiation in Daspletosaurus and Gorgosaurus.

Dale Russell hypothesized that the more lightly built and more common Gorgosaurus may have preyed on the abundant hadrosaurs of the time, while the more robust and less common Daspletosaurus may have specialized on the less prevalent but better-defended ceratopsids, which may have been more difficult to hunt.
However, a specimen of Daspletosaurus (OTM 200) from the Two Medicine Formation preserves the digested remains of a juvenile hadrosaur in its gut region.
The higher and broader muzzles of tyrannosaurines like Daspletosaurus are mechanically stronger than the lower snouts of albertosaurines like Gorgosaurus, although tooth strengths are similar between the two groups.
This may indicate a difference in feeding mechanics or diet.

Other authors have suggested that competition was limited by geographical separation.
Unlike some other groups of dinosaurs, there appears to be no correlation with distance from the sea.
Neither Daspletosaurus nor Gorgosaurus was more common at higher or lower elevations than the other.
However, while there is some overlap, Gorgosaurus appears to be more common at northern latitudes, with species of Daspletosaurus more abundant to the south.
The same pattern is seen in other groups of dinosaurs.
Chasmosaurine ceratopsians and hadrosaurine hadrosaurs (a group now generally referred to as saurolophines) are also more common in the Two Medicine Formation and in southwestern North America during the Campanian.
Thomas Holtz has suggested that this pattern indicates shared ecological preferences between tyrannosaurines, chasmosaurines and hadrosaurines.
Holtz notes that, at the end of the later Maastrichtian stage, tyrannosaurines like Tyrannosaurus rex, hadrosaurines and chasmosaurines like Triceratops were widespread throughout western North America, while albertosaurines and centrosaurines became extinct, and lambeosaurines were very rare.
In the late Campanian of North America, Daspletosaurus was a contemporary of the albertosaurine tyrannosaurid Gorgosaurus. This is one of the few examples of two tyrannosaur genera coexisting. In modern predator guilds, similar-sized predators are separated into different ecological niches by anatomical, behavioral or geographical differences that limit competition. Several studies have attempted to explain niche differentiation in Daspletosaurus and Gorgosaurus.
Dale Russell hypothesized that the more lightly built and more common Gorgosaurus may have preyed on the abundant hadrosaurs of the time, while the more robust and less common Daspletosaurus may have specialized on the less prevalent but better-defended ceratopsids, which may have been more difficult to hunt. However, a specimen of Daspletosaurus (OTM 200) from the Two Medicine Formation preserves the digested remains of a juvenile hadrosaur in its gut region. The higher and broader muzzles of tyrannosaurines like Daspletosaurus are mechanically stronger than the lower snouts of albertosaurines like Gorgosaurus, although tooth strengths are similar between the two groups. This may indicate a difference in feeding mechanics or diet.
Other authors have suggested that competition was limited by geographical separation. Unlike some other groups of dinosaurs, there appears to be no correlation with distance from the sea. Neither Daspletosaurus nor Gorgosaurus was more common at higher or lower elevations than the other. However, while there is some overlap, Gorgosaurus appears to be more common at northern latitudes, with species of Daspletosaurus more abundant to the south. The same pattern is seen in other groups of dinosaurs. Chasmosaurine ceratopsians and hadrosaurine hadrosaurs (a group now generally referred to as saurolophines) are also more common in the Two Medicine Formation and in southwestern North America during the Campanian. Thomas Holtz has suggested that this pattern indicates shared ecological preferences between tyrannosaurines, chasmosaurines and hadrosaurines. Holtz notes that, at the end of the later Maastrichtian stage, tyrannosaurines like Tyrannosaurus rex, hadrosaurines and chasmosaurines like Triceratops were widespread throughout western North America, while albertosaurines and centrosaurines became extinct, and lambeosaurines were very rare.
Daspletosaurus