Contact: Steve Koppes
University of Chicago
Caption: A colony of Monograptus priodon, a neograptine graptolite species that arose after the Ordovician mass extinction. Neograptines, a form of zooplankton, did not rapidly evolve new physical traits until about 2 million years after the extinction event. The specimen measures approximately one millimeter (four hundreds of an inch) wide.
Credit: Charles Mitchell, University of Buffalo, SUNY
Usage Restrictions: News organizations may use this image in connection with reports about the research of Charles Mitchell and David Bapst.
Related news release: Explosive evolution need not follow mass extinctions, study of ancient zooplankton finds