1. Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Oxford Street, Boston, MA 02138, USA
2. Department of Natural Sciences, Amgueddfa Cymru-National Museum Wales, Cathays Park, Cardiff CF10 3NP, UK
3. Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39 East Beijing Road, Nanjing 210008, People's Republic of China