In 1911, Barnum Brown, during the second year of American Museum of Natural History operations in Alberta, uncovered a fragmentary partial Albertosaurus skull at the Red Deer River near Tolman Bridge, specimen AMNH 5222.

William Parks described a new species in 1928, Albertosaurus arctunguis, based on a partial skeleton lacking the skull excavated by Gus Lindblad and Ralph Hornell near the Red Deer River in 1923, but this species has been considered identical to A. sarcophagus since 1970.
Parks' specimen (ROM 807) is housed in the Royal Ontario Museum in Toronto.

Between 1926 and 1972, no Albertosaurus fossils were found at all; but, since the seventies, there has been a steady increase in the known material.
Apart from the Dry Island bonebed, six more skulls and skeletons have since been discovered in Alberta and are housed in various Canadian museums: specimens RTMP 81.010.001, found in 1978 by amateur paleontologist Maurice Stefanuk; RTMP 85.098.001, found by Stefanuk on 16 June 1985; RTMP 86.64.001 (December 1985); RTMP 86.205.001 (1986); RTMP 97.058.0001 (1996); and CMN 11315.
However, due to vandalism and accidents, no undamaged and complete skulls could be secured among these finds.
Fossils have also been reported from the American states of Montana, New Mexico, Wyoming, and Missouri, but these probably do not represent A. sarcophagus and may not even belong to the genus Albertosaurus.

Two specimens from ("cf Albertosaurus ".sp") have been found in Mexico (Packard Formation and Corral de Enmedio Formation).
In 1911, Barnum Brown, during the second year of American Museum of Natural History operations in Alberta, uncovered a fragmentary partial Albertosaurus skull at the Red Deer River near Tolman Bridge, specimen AMNH 5222.
William Parks described a new species in 1928, Albertosaurus arctunguis, based on a partial skeleton lacking the skull excavated by Gus Lindblad and Ralph Hornell near the Red Deer River in 1923, but this species has been considered identical to A. sarcophagus since 1970. Parks' specimen (ROM 807) is housed in the Royal Ontario Museum in Toronto.
Between 1926 and 1972, no Albertosaurus fossils were found at all; but, since the seventies, there has been a steady increase in the known material. Apart from the Dry Island bonebed, six more skulls and skeletons have since been discovered in Alberta and are housed in various Canadian museums: specimens RTMP 81.010.001, found in 1978 by amateur paleontologist Maurice Stefanuk; RTMP 85.098.001, found by Stefanuk on 16 June 1985; RTMP 86.64.001 (December 1985); RTMP 86.205.001 (1986); RTMP 97.058.0001 (1996); and CMN 11315. However, due to vandalism and accidents, no undamaged and complete skulls could be secured among these finds. Fossils have also been reported from the American states of Montana, New Mexico, Wyoming, and Missouri, but these probably do not represent A. sarcophagus and may not even belong to the genus Albertosaurus.
Two specimens from ("cf Albertosaurus ".sp") have been found in Mexico (Packard Formation and Corral de Enmedio Formation).
Albertosaurus