Albertosaurus (/ælˌbɜ rtəˈsɔ rəs/; meaning "Alberta
lizard") is a genus of tyrannosaurid theropod dinosaur that lived in western North
America during the Late Cretaceous
Period, about 70 million years ago. The type species, Albertosaurus sarcophagus, was apparently restricted in range to the modern-
day Canadian province of Alberta, after which the genus is named. Scientists disagree on the content of the genus, with some recognizing Gorgosaurus libratus as a second species.
As a tyrannosaurid, Albertosaurus was a bipedal predator with tiny, two-fingered hands and a massive head that had dozens of large, sharp
teeth. It may have been at the top of the food chain in its local ecosystem. While Albertosaurus was large for a theropod, it was much smaller than its larger and more famous relative Tyrannosaurus rex, growing nine to ten meters
long and possibly weighing less than 2 metric tons.
Since the first discovery in 1884, fossils of more than 30 individuals have been recovered, providing scientists with a more detailed
knowledge of Albertosaurus anatomy than is available for most other tyrannosaurids. The discovery of
26 individuals at one site provides evidence of
pack behaviour and allows studies of ontogeny and population biology, which are impossible with lesser-known dinosaurs.
