Study shows largest North America climate change in 65 million years

University of Florida vertebrate paleontologist Bruce MacFadden examines a fossil oreodont jaw from Nebraska in the Florida Museum of Natural History collections in Gainesville, Fla., on Jan. 30, 2007. MacFadden is part of a team that is the first to use fossil teeth and bones to provide evidence of a dramatic climate change about 33.5 million years ago. Credit: University of Florida