ACKNOWLEDGMENTS

I thank the numerous people that worked with me through the years of data collecting while working in the Judith River Formation of south-central Montana, with particular thanks to Dr. P. Dodson for his help excavating this tracksite. I am also grateful to Jess, Nicki and Emmy Llou Garfield for access to their land. I also thank D. Vineyard and Drs. L. Jacobs and L. Taylor for their comments on an earlier version of this manuscript. Funds for this project were provided largely by National Science Foundation grants EAR 84-08446 and EAR 87-21432. I gratefully acknowledge the staff of the Philadelphia Zoo for their willingness to allow me access to their collection of Galapagos turtles. Lastly, I dedicate this project to Will Downs. Although he did not work directly with me on this particular study, Will contributed greatly to my training as a graduate student, and ultimately that training led to this work.