Albertosaurus was a tyrannosaurid from North America, that lived 75 million years ago. Though it was originally found in Alberta, like its name suggests, more fossils have been recovered from all over the continent. It reached 10 metres long, and 4.5 metres high.
It was a smaller, sleeker model of the Tyrannosaurus, and had longer arms in proportion to it's body.
Like T-Rex, it may have hunted in packs. The prey it would have lived with include the ceratopsian Pachyrhinosaurus, and it would have hunted in packs to attack a herd, like raptors did.
The Albertosaurus had jaws full of sharp teeth, designed for tearing flesh and bone. It had a bite force less than that of T-Rex, but it was still a powerful predator. Its long legs could carry it at speeds of 25mph, which would be fast enough to chase down Pachyrhinosaurus. However, its bones were hollow, and fairly delicate, so Albertosaurus had to be very careful when attacking.
Though Albertosaurus is less well known than T-Rex, it has appeared in the TV Series 'Jurassic Fight Club' (known as Dinosaur Secrets in the UK). It was seen stalking Pachyrhinosaurus, and they had a feast when a herd of Pachyrhinosaurus drowned in a flooded river and were washed ashore. Albertosaurus also features in the final episode of 'Prehistoric Park'. It is seen competing with Deinosuchus over food. Deinosuchus is a giant crocodile, and, being larger than Albertosaurus, outcompetes it. But in reality, Tyrannosaurus rex came to North America and outcompeted albertosaurus. Albertosaurus also appears in Jurassic Park: Operation Genesis.