Several people contributed to this project. Christina Cleburn, Joseph A. Devera, Wayne T. Frankie, Dennis R. Kolata, Rodney D. Norby, and George L.H. Stone are thanked for their loan of fossil specimens. The manuscript reviews of Dennis R. Kolata, Rodney D. Norby, and Wayne T. Frankie are appreciated. Illustrations were prepared by Margaret L. Whaley, Charles Collinson, and Marie E. Litterer. Pamella K. Carrillo created the cover design and layout. Production editor was Cheryl K. Nimz. Photographs were taken by Joel M. Dexter. The Web version of this publication was created by Sally L. Denhart.