Single dinosaur community populated North America

Last Updated: Sat, Apr 24, 2010 10:30 hrs

Researchers have discovered that the entire western interior of North America was 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 Hans Larsson, McGill University professor, and Matthew Vavrek, doctoral student at the university.

Using data from the Paleobiology Database, they found that the difference in species across regions in 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 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, said a McGill release.

'This is significant because we lack living analogues of a complete terrestrial megafauna living in those kinds of stable climates. The findings give us an insight into what kind of ranges these types of communities may have had,' explained Larsson.

'We also demonstrate that after more than a century of collecting dinosaurs in North America, we should expect to find about 16 types, on average, in any one region of western North America just before their mass extinction,' added Larsson.

The long extinct dinosaurs are not just long dead fossils, but they offer a unique insight into a complex megafauna that responded to their environment.

The paper was published in the April issue of the Proceedings of the National Academy of Sciences.