Shengjun Tan, Yan Zhong, Huan Hou, Sihai Yang* and Dacheng Tian*
* Corresponding authors: Sihai Yang sihaiyang@nju.edu.cn - Dacheng Tian dtian@nju.edu.cn
BMC Evolutionary Biology 2012, 12:86 doi:10.1186/1471-2148-12-86