The type specimen of Daspletosaurus torosus (CMN 8506) is a partial skeleton including the skull, the shoulder, a forelimb, the pelvis, a femur, and all of the vertebrae from the neck, torso, and hip, as well as the first eleven tail vertebrae. It was discovered in 1921 near Steveville, Alberta, by Charles Mortram Sternberg, who thought it was a new species of Gorgosaurus. It was not until 1970 that the specimen was fully described by Dale Russell, who made it the type of a new genus, Daspletosaurus, from the Greek δασπλής (, stem and connective vowel resulting in -) ("frightful") and () ("lizard"). The type species is Daspletosaurus torosus, the specific name torosus being Latin for 'muscular' or 'brawny'. Aside from the type, there is only one other well-known specimen, RTMP 2001.36.1, a relatively complete skeleton discovered in 2001. Both specimens were recovered from the Oldman Formation in the Judith River Group of Alberta. The Oldman Formation was deposited during the middle Campanian stage of the Late Cretaceous, from about 79.5 to 77 Ma (million years ago).
