Gorgosaurus

Gorgosaurus was a fast, formidable tyrannosaurid predator native to western North America during the Late Cretaceous, about 76 million years ago. Abundantly preserved in Alberta and Montana, it is among the best understood of all tyrannosaurs. Adults measured up to nine metres long and weighed over two tonnes, possessing long lower limbs that made them exceptional sprinters. It coexisted with the more robust Daspletosaurus, likely partitioning resources by targeting faster prey like hadrosaurs. A spectacularly preserved juvenile specimen revealed stomach contents composed of the amputated legs of small feathered oviraptorosaurs, proving juvenile tyrannosaurs targeted smaller game before shifting to megaherbivores as adults.

A juvenile specimen was found preserved with the hind legs of two small caenagnathid dinosaurs inside its gut.

Where and when

Gorgosaurus lived in the Late Cretaceous, from 76.5 to 75 million years ago (Campanian age). Its remains come from Canada and United States, in the Dinosaur Park Formation.

The numbers

Length 8.5 m (estimates run from 8 to 9 m). Mass about 2.4 t. Hip height about 2.7 m. That is 5 human-lengths, or 0.76 of a double-decker bus. These are estimates from near-complete skeleton; fields marked estimated by the site are length, mass, hip height.

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