Albertosaurus was a large carnivorous dinosaur that lived during the late Cretaceous period, around 70 million years ago. It belonged to the theropod group, which includes other well-known dinosaurs like Tyrannosaurus rex. Albertosaurus was characterized by its long legs, sharp teeth, and a relatively lightweight body, making it an agile predator. Fossils of Albertosaurus have been found primarily in North America, particularly in Canada. It is believed to have hunted in packs, which may have helped it take down larger prey. The dinosaur could grow up to 30 feet long and was an important part of its ecosystem during its time.