Dr. Hamed Sanei (right), Steve Grasby (center) and Dr. Benoit Beauchamp (left) discovered another key player assisting in Earth's greatest extinction: mercury. Dr. Benoit Beauchamp (left) is a professor at the University of Calgary. Dr. Hamed Sanei (right) and Steve Grasby (center) are research scientists at Natural Resources Canada and adjunct professors at the University of Calgary. Credit: University of Calgary, Riley Brandt