1. S. Weiner, Department of Structural Biology, Weizmann Institute of Science, Rehovot, Israel 76100. Q. Xu and J. Liu, Institute of Vertebrate Paleontology and Paleoanthropology, Academica Sinica, Post Office Box , Beijing 100044, People's Republic of China. P. Goldberg, Department of Archaeology, Boston University, 675 Commonwealth Avenue, Boston, MA 02215, USA. O. Bar-Yosef, Department of Anthropology, Harvard University, Cambridge, MA 02138, USA.