Albertosaurus

Dinosaurs in the genus Albertosaurus were carnivorous dinosaurs of the Tyrannosauridae family that lived more than 70 million years ago in western North America, in what is now the province of Alberta Canada.

These smaller, older relatives of the popular Tyrannosaurus Rex were still formidable carnivores. Fossil discoveries of up to twenty Albertosaurs in one location have lead scientists to believe these bipedal, elephant-sized predators lived and hunted in packs. By the age of two, an Albertosaurus would have been the largest carnivorous animal in its environment... and had its buddies to help it out!

A wealth of specimens extracted from the fossil record have given scientists an excellent range of data on how and where Albertosaurus lived. The youngest specimen found is estimated to have been approximately two years old at the time of death and was already the size and weight of a small human. Based on available evidence, it's estimated the creatures put on at least 250 pounds per year until it was fully grown.

The assumption of pack social behavior is based on the wide range of ages found in Albertosaurus fossil beds. Phillip J. Currie hypothesizes that younger, lighter, more fleet-of-foot Albertosaurs may have chased prey animals toward older, more powerful members of the pack as a predation strategy.