Phylogenetic relationships of Pseudohynobius (Urodela, Hynobiidae) inferred from DNA barcoding analysis

As a proven tool, DNA barcoding can identify species rapidly and unambiguously. In this study, we used mtDNA cyt b, COI, and 16s rRNA sequences of six species of Pseudohynobius, Protohynobius puxiongensis, Liua shihi, Ranodon sibiricus, and Pachyhynobius shangchengensis, to reconstruct the phylogenetic relationships using Bayesian inference and maximum likelihood methods. Approximate lineage divergence times were also estimated, the divergence between them was calculated to have taken place mainly in Miocene. Our results showed that: 1) Ps. guizhouensis is an independent and valid species that is a sister species to Ps. kuankuoshuiensis; 2) five Pseudohynobius species formed a monophyletic group; 3) Ps. tsinpaensis is different from L. shihi, and should be classified as belonging to the Liua genus; and 4) Pr. puxiongensis is the sister lineage to all Pseudohynobius species, and should therefore be named Pseudohynobius puxiongensis.