The taxonomic status of red knobby newt (Tylototriton shanjing) is under dispute. Molecular phylogenetic tree of Tylototriton verrucosus group was reconstructed based on 753 bp of partial mitochondrial cyt b gene sequence to determine species boundaries among the species in T. verrucosus group. The phylogeny result indicates that four major clades (clade I-IV) can be distinguished within Tylototriton verrucosus group. Clade I and IV consist of T. taliangensis and T. kweichowensis, respectively. Clade II consists of samples of T. shanjing derived from Yunnan of China, a form that researchers resurrect from its synonym under T. verrucosus. T. verrucosus haplotypes from Shan State of Myanmar and pet trade formed clade III. All populations of T. shanjing and T. verrucosus formed strongly supported (PP = 1.0) reciprocal monophyletic groups. The average uncorrected pairwise genetic distance (p-distance) of cyt b between these four clades ranges from 0.060-0.089 which is obviously higher than within these four major clades (0.001-0.014). Researchers propose that the T. shanjing should be a valid species rather than synonym of T. verrucosus.
Mingwang Zhang, Guohua Yu, Dingqi Rao, Yimei Huang, Junxing Yang and Yan Li, 2013. A Species Boundary Within the Tylototriton verrucosus Group (Urodela: Salamandroidae) Based on Mitochondrial DNA Sequence Evidence. Journal of Animal and Veterinary Advances. 12: 337-343.