Albertosaurus (Al-ber-to-sore-us), Alberta Lizard, lived in the Late Cretaceous period of North America. Albertosaurus libratus = Gorgosaurus from the late Campanian and the type species Albertosaurus sarcophagus from the early Masstrictian are found in the northern part of western North America. They are associated with a fauna of centrosaurines and lambeosaurines. Albertosaurus montogomeriensis = Appalachiosaurus lived in the eastern part of North America. Isolated teeth referred to Albertosaurus are known from the latest Maastrichtian. It may have been displaced when Tyrannosaurus migrated from Asia later in the Cretaceous (Paul, 2010).
1. Genera & species
3. History of Discovery
Genera and Species
Classification: Theropoda, Tetanurae, Coelurosauria, Tyrannosauroidea
Species: A. sarcophagus, A. megagracilis, A. sternbergi, A. libratus, A. jimmaden and A. montogomeriensis
Senior synonyms: A. arctunguis, Deinodon sarcophagus, D. arctunguis, Dryptosaurus sarcophagus, Laelaps incrassatus and Dryptosaurus incrassatus.
Albertosaurus was a smaller version of Tyrannosaurus, about half the size of its younger relative. It was lighter and faster, with puny arms but more teeth in a relatively broad snout. The skull had hornlets useful for display with pebbly skin. The young animals had longer legs that would have allowed them to chase down fleet-footed plant eaters (Worth, 1999).
Size LENGTH: 8 - 11 m (27 - 36 ft). WEIGHT: 1.8 - 2.5 tons.
It preyed on the unarmed hardrosaurs Edmontosaurus, Saurolophus, Hypacrosaurus and Stegoceras. The discovery of bone beds suggest that albertosaurs formed social groups for hunting with younger faster juveniles herding prey for adult animals to ambush.
History of Discovery
Discovery, 1884, in Alberta Canada by JB Tyrrell, albertosaurines are known from over 26 skeletons.
Found in North America (Alberta Canada; Montana, Wyoming, Alaska and Alabama USA) in well watered forested plains with marshes and swamps and in drier uplands(Paul, 2010).
1. Paul, G. (2010). The Princeton Field Guide to Dinosaurs (pp. 2738). Princeton, New Jersey: University Press Princeton.
2. Worth, G. (1999). The Dinosaur Encyclopaedia (pp. 248). Scarborough, Western Australia: HyperWorks Reference Software.
3. Griffin. (2010, July 9). Albertosaurus. . Retrieved April 3, 2014,
4. Knol, R. (2012). Late Cretaceous Edmontonian Horseshoe Canyon Formation.