Bayesian inference tree of Oligodon derived from the analysis of 3,019 bp of 12S rRNA–16S rRNA and cyt b mitochondrial DNA gene sequences. For voucher specimen information and GenBank accession numbers see Table 1. Numbers at tree nodes correspond to BI PP/ML BS support values, respectively; an en-dash denotes no support. Outgroup taxa are not shown. Colors of clades and locality numbers correspond to those in Fig. 1. Photographs taken by Nikolay A. Poyarkov Jr.