1. K. C. Beard and M. R. Dawson, Section of Vertebrate Paleontology, Carnegie Museum of Natural History, 4400 Forbes Avenue, Pittsburgh, PA 15213, USA.
2. Y. Tong, J. Wang, X. Huang, Institute of Vertebrate Paleontology and Paleoanthropology, Academia Sinica, Post Office Box 643, Beijing, People's Republic of China, 100044.