Ancient Global Warming Spurred Primates Into North America, Fossils Show

An ancient period of global warming spurred the world's first primates to spread from Asia to North America, new research shows.

The animals may have taken as little as 20,000 years to disperse across the Northern Hemisphere from the moment they first appeared.

The findings were reported by scientists studying the fossils of animals called Teilhardina, which have been found in China, Belgium, and the western United States.

Teilhardina were tiny primates about the size of chipmunks that jumped through the forest from tree to tree, says paleontologist Philip Gingerich.

Gingerich, from the University of Michigan, is a co-author of the new study, which appears in the July 25 issue of the Proceedings of the National Academy of Sciences.