1. Yunnan Key Laboratory for Palaeobiology; Yunnan University; Kunming 650091 China
2. Department of Earth Sciences; Natural History Museum; Cromwell Road London SW7 5BD UK
3. MEC International Joint Laboratory for Palaeobiology & Palaeoenvironment; Yunnan University; Kunming 650091 China
4. Institute of Earth Sciences; University of Lausanne; Lausanne CH-1015 Switzerland
5. Management Committee of the Chengjiang Fossil Site World Heritage; Chengjiang 652599 China
6. Department of Zoology; University of Oxford; Oxford OX1 3PS UK