Paleontologist Derek Larson of the Royal Ontario Museum, who spent six years analyzing fossilized dinosaur teeth, has identified more than 20 species of small meat-eating dinosaurs that lived in western North America during the Cretaceous period. A Troodon, one of the small carnivores characteristic of Alberta dinosaurs, tries to catch a toothed bird (Jan Sovak) Larson and his research supervisor Prof Philip Currie of the University of Alberta report...