M. K. Brett-Surman is Assistant Professorial Lecturer in Paleontology at George Washington University and museum specialist at the National Museum of Natural History of the Smithsonian Institution. He has named three duckbill dinosaurs, Anatotitan, Gilmoreosaurus, and Secernosaurus.Thomas R. Holtz, Jr., is Senior Lecturer and Director, Earth, Life and Time Program, Department of Geology, University of Maryland.James O. Farlow is Professor of Geosciences at Indiana University--Purdue University at Ft. Wayne. An expert on dinosaur tracks and trackways, Farlow has written about dinosaurs for a variety of audiences and currently supervises a Miocene dig at Pipe Creek in Indiana.