Height :  2.75 m (9ft)

Length: 9 m (30 ft)

Weight :  1.5 tonnes (1.65 tons)

Albertosaurus was a tyrannosaur, a carnivore that lived around 75 million years ago during the middle of the Cretaceous period, ten million years before its more famous relative Tyrannosaurus rex. Like the other tyrannosaurs Albertosaurus walked on two powerful hind legs armed with clawed, four-toed feet (the first toe was short and didn't contact the ground). A large head was typically full of around 34 sharp serrated teeth; each tooth having another tooth growing up from under it to replace it when it came out. The head was balanced by a long stiff tail and the front arms were short to compensate for the excessive weight of the large head and torso. Powerful hind legs suggest that the tyrannosaurs could run fairly fast in pursuit of prey but some scientists argue that T-Rex would have been fatally injured if it fell at speed. Albertosaurus, being smaller than T-Rex, may have been able to recover from injuries caused by falls and could possibly have been a successful hunter.

A large number of specimens have been found together at one location, apparently having all died at the same time. The has led to the claim that Albertosaurus operated in packs. Others believe that the animals were forced together before being consumed by floods or some other terrible event.

The first Albertosaurus fossils were found by Joseph Burr Tyrrell in the Canadian province of Alberta in 1884. More have been found since in Canada and the western USA. Albertosaurus was named in 1905 by Henry Fairfield Osborn.

  • Dinosauria (Dinosaurs)
    • Saurischia (Lizard Hipped)
      • Theropods (bipedal, mostly carnivores)
        • Coelurosaurians
          • Tyrannosauroids
            • Albertosaurus (Late Cretaceous, western North America)
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