More Small Meat-Eating Dinosaurs Existed than Previously Thought

A new study reveals that there were more small meat-eating dinosaurs in western Canada and the United States than previously thought.

So far, only seven species of small meat-eating dinosaurs from the North American west were identified. But a team of researchers from University of Alberta, Canada, have identified at least 23 species of such small dinosaurs, which roamed some 85 to 65 million years ago.

For their study, paleontologist Philip Currie and his student Derek Larson from University of Alberta analyzed the dataset of fossilized teeth samples of dinosaurs of the family to which Troodon (possibly the brainiest dinosaur) and velociraptor (a prehistoric carnivore that had several similarities between dinosaurs and birds) belonged.

Based on their observations, researchers found that there are 23 small, two-legged meat-eating dinosaurs. "Small meat-eating dinosaur skeletons are exceedingly rare in many parts of the world and, if not for their teeth, would be almost completely unknown," Larson said in a statement.

"We can identify what meat-eaters lived in what geographic area or geologic age," explained Currie, adding, "And we can do this by identifying just their teeth, which are far more common than skeletons."

The researchers conclude that the discovery of a large number of meat-eating dinosaurs suggests that there were more number of small carnivore dinosaurs that existed for shorter periods, instead of few species of dinosaurs that existed for millions of years.

Dinosaurs became extinct some 65 million years ago. For several years, scientists have debated on what killed the dinosaurs. A largely accepted theory is that an asteroid collision with Earth wiped out the animal at the end of the Cretaceous geological period.

The findings of the study appear in the journal PLOS ONE