Travel back 300 million years to the emergence of Earth's first herbivores - the diadectids - an important step in the evolution of Earth's modern ecosystems. Listen in as Richard Kessel of The Field Museum's Exhibitions Department, dissects the herbivore's roles in the larger ecosystem and shows how paleontologists interpret the diets of these and other long-extinct creatures.

Recorded Saturday, May 13, 2006 at The Field Museum.