Institute of Geology;
Chinese Academy of Geological Sciences;
Beijing 100037;
China;
Fossil Research and Development Center of the Third Geology and Mineral Resources Exploration Academy of Gansu Province;
Lanzhou;
Gansu 730050;
China;
Section of Vertebrate Paleontology;
Carnegie Museum of Natural History;
4400 Forbes Avenue;
Pittsburgh;
PA 15213;
USA;
Department of Animal Biology;
School of Veterinary Medicine;
University of Pennsylvania;
3800 Spruce Street;
Philadelphia;
PA 19104;
USA;