Brandon University biology professor David Greenwood says parts of Canada that were tropical 50 million years ago were more diverse than thought.
Greenwood studied fossil beds from British Columbia and Washington state, with team members Bruce Archibald and Rolf Mathewes, evolutionary biologists at Simon Fraser University.
"Tropical mountains are highly diverse because migration between mountains is more difficult than in temperate areas," Greenwood said in a statement.
The research team was seeking to confirm an influential ecological theory explaining the diversity of life in the modern world.
Their findings have been published in the international scientific journal Palaeogeography, Palaeoclimatology, Palaeoecology.