Researchers at McGill University are unlocking the mysteries of the little-known habits of dinosaurs in discovering that the entire western interior of North America was likely once populated by a single community of dinosaurs. According to a statistical analysis of the fossil record, dinosaurs were adept at coping with all sorts of environments, and not as restricted in their geographic ranges as previously thought.

The discovery was made by McGill Professor Hans Larsson and Matthew Vavrek, a PhD student at the University. Using data from the Paleobiology Database (http://www.paleodb.org/), they found that the difference in species between regions over North America was relatively low -- low enough to consider it a single homogeneous fauna. The finding is significant as it confirms that dinosaur ecosystems may have been as large as continents. The paper is published in the April 19 issue of the journal Proceedings of the National Academy of Sciences.

The McGill team zeroed in on alpha diversity, the number of species in an immediate area, versus beta diversity, which are the differences in species between two different areas. Their research shows low beta biodiversity among these dinosaurs with values comparable to species living in homogeneous climates today, but on smaller geographic scales.