Kirk R. Johnson is vice president and chief curator at the Denver Museum of Nature and Science. He received his PhD in geology and paleobotany from Yale University in 1989, and did postdoctoral research in the rainforests of northern Australia before coming to Denver in 1991, where he directed the installation of the museum's Prehistoric Journey exhibit. Richard Stucky is the curator of paleoecology and evolution at the Denver Museum of Nature and Science. He holds a Ph.D. from the University of Colorado at Boulder in anthropology. His research has shed light on the ecology and evolution of early Tertiary mammals.