ACKNOWLEDGMENTS
Our research in Zambia has been supported by the National Geographic Society (CRE 8571-088 to J.S.S., CRE 8961-11 to C.A.S.), with additional support from The Grainger Foundation and the Field Museum/IDP, Inc. African Partner's Program (to K.D.A.), and NSF EAR-1337569 (to C.A.S.), and EAR-1337291 (to K.D.A.). B.R.P. was supported by a NSF Graduate Research Fellowship. We thank K. Mwamulowe and J. Museba (NHCC) for assistance in arranging and carrying out the field work. Fossil preparation was skillfully performed by G. Livingston and B. Crowley (Burke Museum). We acknowledge the fine illustrations made by M. Schumacher in and B. Strack (Field Museum) for assistance with the electron micrograph in . Finally, we thank J. Cisneros, M. Day, I. Nyambe, and B. Rubidge for their helpful reviews.
Handling editor: Bruce Rubidge.