Two or three additional species have been assigned to the genus Daspletosaurus over the years, although as of 2007 none of these species has received a proper description or scientific name.
In the meantime, all are designated as Daspletosaurus spp; this does not imply that they all are the same species.

Along with the holotype, Russell designated a specimen collected by Barnum Brown in 1913 as the paratype of D. torosus.
This specimen (AMNH 5438) consists of parts of the hindleg, the pelvis and some of its associated vertebrae.
It was discovered in the Dinosaur Park Formation in Alberta.
The Dinosaur Park Formation was formerly known as the Upper Oldman Formation and dates back to the middle Campanian, between 76.5 and 74.8 million years ago.
Daspletosaurus fossils are known specifically from the middle to upper section of the formation, between 75.6 and 75.0 million years ago.
In 1914, Brown collected a nearly complete skeleton and skull; forty years later his American Museum of Natural History sold this specimen to the Field Museum of Natural History in Chicago.
It was mounted for display in Chicago and labeled as Albertosaurus libratus for many years, but after several skull features were later found to be modeled in plaster, including most of the teeth, the specimen (FMNH PR308) was reassigned to Daspletosaurus torosus by Thomas Carr in 1999.
A total of eight specimens have been collected from the Dinosaur Park Formation over the years since, most of them within the boundaries of Dinosaur Provincial Park.
Phil Currie believes that the Dinosaur Park specimens represent a new species of Daspletosaurus, distinguished by certain features of the skull.
Pictures of this new species have been published, but it still awaits a name and full description in print.

A new tyrannosaurid specimen (OMNH 10131), including skull fragments, ribs and parts of the hindlimb, was reported from New Mexico in 1990 and assigned to the now-defunct genus Aublysodon.
Many later authors have reassigned this specimen, along with a few others from New Mexico, to yet another unnamed species of Daspletosaurus.
However, research published in 2010 showed that this species, from the Hunter Wash Member of the Kirtland Formation, is actually a more primitive tyrannosauroid, and was classified in the genus Bistahieversor.
There is currently disagreement over the age of the Kirtland Formation, with some workers claiming a late Campanian age, while others suggest a younger age in the early Maastrichtian stage.

In 1992, Jack Horner and colleagues published an extremely preliminary report of a tyrannosaurid from the upper parts of the Campanian Two Medicine Formation in Montana, which was interpreted as a transitional species between Daspletosaurus and the later Tyrannosaurus.
Currie (2003) stated that the tyrannosaurid from the Two Medicine Formation mentioned by Horner et al. (
1992) may be an unnamed third species of Daspletosaurus.
Another partial skeleton was reported from the Upper Two Medicine in 2001, preserving the remains of a juvenile hadrosaur in its abdominal cavity.
This specimen was assigned to Daspletosaurus but not to any particular species.
The remains of at least three more Daspletosaurus have also been described in a Two Medicine bonebed by Currie et al. (
2005); the authors stated that this fossil material likely represents then-unnamed species mentioned by Horner et al. (
1992), but cautioned that further study and description of Daspletosaurus would be necessary before the species can be determined with certainty.
In 2017, the Two Medicine Formation taxon was named as the new species D. horneri.

Isolated tyrannosaurid teeth in the upper portions of the Judith River Formation are likely from Gorgosaurus as well as some species of Daspletosaurus, probably D. torosus.
However, in the lower portion Judith River formation, around 78 million years ago, there is some evidence for a new undescribed tyrannosaurid taxon.
A specimen in the collections of Triebold Paleontology excavated between 2002 and 2004, known as "Sir William", shows some charact
Two or three additional species have been assigned to the genus Daspletosaurus over the years, although as of 2007 none of these species has received a proper description or scientific name. In the meantime, all are designated as Daspletosaurus spp; this does not imply that they all are the same species.
Along with the holotype, Russell designated a specimen collected by Barnum Brown in 1913 as the paratype of D. torosus. This specimen (AMNH 5438) consists of parts of the hindleg, the pelvis and some of its associated vertebrae. It was discovered in the Dinosaur Park Formation in Alberta. The Dinosaur Park Formation was formerly known as the Upper Oldman Formation and dates back to the middle Campanian, between 76.5 and 74.8 million years ago. Daspletosaurus fossils are known specifically from the middle to upper section of the formation, between 75.6 and 75.0 million years ago. In 1914, Brown collected a nearly complete skeleton and skull; forty years later his American Museum of Natural History sold this specimen to the Field Museum of Natural History in Chicago. It was mounted for display in Chicago and labeled as Albertosaurus libratus for many years, but after several skull features were later found to be modeled in plaster, including most of the teeth, the specimen (FMNH PR308) was reassigned to Daspletosaurus torosus by Thomas Carr in 1999. A total of eight specimens have been collected from the Dinosaur Park Formation over the years since, most of them within the boundaries of Dinosaur Provincial Park. Phil Currie believes that the Dinosaur Park specimens represent a new species of Daspletosaurus, distinguished by certain features of the skull. Pictures of this new species have been published, but it still awaits a name and full description in print.
A new tyrannosaurid specimen (OMNH 10131), including skull fragments, ribs and parts of the hindlimb, was reported from New Mexico in 1990 and assigned to the now-defunct genus Aublysodon. Many later authors have reassigned this specimen, along with a few others from New Mexico, to yet another unnamed species of Daspletosaurus. However, research published in 2010 showed that this species, from the Hunter Wash Member of the Kirtland Formation, is actually a more primitive tyrannosauroid, and was classified in the genus Bistahieversor. There is currently disagreement over the age of the Kirtland Formation, with some workers claiming a late Campanian age, while others suggest a younger age in the early Maastrichtian stage.
In 1992, Jack Horner and colleagues published an extremely preliminary report of a tyrannosaurid from the upper parts of the Campanian Two Medicine Formation in Montana, which was interpreted as a transitional species between Daspletosaurus and the later Tyrannosaurus. Currie (2003) stated that the tyrannosaurid from the Two Medicine Formation mentioned by Horner et al. (1992) may be an unnamed third species of Daspletosaurus. Another partial skeleton was reported from the Upper Two Medicine in 2001, preserving the remains of a juvenile hadrosaur in its abdominal cavity. This specimen was assigned to Daspletosaurus but not to any particular species. The remains of at least three more Daspletosaurus have also been described in a Two Medicine bonebed by Currie et al. (2005); the authors stated that this fossil material likely represents then-unnamed species mentioned by Horner et al. (1992), but cautioned that further study and description of Daspletosaurus would be necessary before the species can be determined with certainty. In 2017, the Two Medicine Formation taxon was named as the new species D. horneri.
Isolated tyrannosaurid teeth in the upper portions of the Judith River Formation are likely from Gorgosaurus as well as some species of Daspletosaurus, probably D. torosus. However, in the lower portion Judith River formation, around 78 million years ago, there is some evidence for a new undescribed tyrannosaurid taxon. A specimen in the collections of Triebold Paleontology excavated between 2002 and 2004, known as "Sir William", shows some charact
Daspletosaurus