Albertosaurus, Dinosaur, Cretaceous Period

It seems people everywhere are re-discovering a fascination with the "Age of Reptiles", a period in which the dinosaur was the dominant land creature. Canada Post Corporation is contributing to this phenomena with its issue of four stamps featuring three dinosaurs and one marine reptile to launch Stamp Month on October 1, 1993. The dinosaurs had 165 million years of domination of the earth from approximately 230 million to 65 million years ago. One theory of why the great beasts became extinct is because they could not adjust to drastic climatic changes brought about by a giant asteroid striking the Earth. Remains of dinosaurs have been found on all continents, with the first Canadian discovery being made at Morgan Creek, Saskatchewan in 1874 by geologists of Her Majesty's North American Boundary Commission. The famous "badlands" of Alberta yielded the most dinosaur finds in Canada to date. The Albertosaurus were Cretaceous-period flesh-eating dinosaurs belonging to the group Tyrannosauride. Slightly smaller than their better known cousin, the Tyrannosaurus, they were powerful beasts which is probably tore huge pieces of flesh from their living prey. These dinosaurs had large heads, wart-like bony growths on the bridge of the nose, long teeth, and foot claws which were more hoof-like than sickle-shaped. They weighed approximately two and a half metric tonnes with a length of about 10 meters. They inhabited the flood plains and deltas which separated the Rocky Mountains from the coastline of the interior seaway to the east and existed between 83 and 65 million years ago. Rolf Harder has designed all three stamps sets in the "Prehistoric Life in Canada" series. The choice of subjects was made on the advice of Canadian paleontologists and reflects importance, location in Canada, and visual suitability for depiction on stamps. A key element in the design is the rendition of the texture of the creature's surface, which is produced by a mezzotint stipple effect. Although the colour of these beasts is subject to speculation, each is shown of a hue appropriate to its surroundings.