For many years, the name Albertosaurus referred to a large number of tyrannosaurids. We know that this specimen is in fact a Gorgosaurus, a species that lived about five million years before Albertosaurus.
Species: Gorgosaurus libratus
Name means: Fierce Lizard
Adult Size: 8 metres long (26 ft)
Weight: 1000 kg (1 tonne)
Age at death: Teenager, only about 70% full-grown adult size.
Lived during: Late Cretaceous (74 million years ago)
Known distribution: Southern Alberta and parts of Montana
Behaviour: This group of dinosaurs probably lived and hunted in packs
Discovery: Found in Dinosaur Provincial Park, Alberta, by Levi Sternberg in 1920. The original fossil bones are at the Royal Ontario Museum.
Other info: In comparison to the related Tyrannosaurus rex, the Gorgosaurus was 2/3 smaller but probably ran faster and had a few more teeth. The two small forearms had two clawed digits or fingers. The teeth had serrated edges like a steak knife for sawing flesh.
Did you know? The right leg was broken. The lower bone of the right leg is lumpier than the left, showing where the bone tissue healed or ossified. Our Gorgosaurus probably walked with a limp. Fractures to this bone are relatively common among tyrannosaurs and the break may have been caused by the tail club of an ankylosaur.
Images from top to bottom:
1) Mike Chung (Redpath Museum).
2) Matt Martyniuk. Accessed at the Wikipedia Commons. License terms.
3) Bruno Paul Stenson (Redpath Museum).
4) Adrian Bobb (Redpath Museum).