Taxonomic relationships between two species of Tylototriton in Shan State, central Myanmar (Amphibia: Urodela: Salamandridae)

We assessed the taxonomic relationship of Tylototriton ngarsuensis Grismer, Wood, Quah, Thura, Espinoza, Grismer, Murdoch & Lin, 2018 and T. shanorum Nishikawa, Matsui & Rao (2014) using partial sequencing of mitochondrial DNA (mtDNA), genome-wide single nucleotide polymorphism obtained by multiplexed inter-simple sequence repeat genotyping by sequencing (MIG-seq), and morphological data. The phylogenetic tree generated using mtDNA showed that the populations of the two species, which were identified by morphological characters, did not separate into two distinct clades, but they were mixed into one clade. Furthermore, the analyses of MIG-seq showed that the populations were grouped according to their locality, regardless of species classification. The mtDNA genetic distances among samples were very small at the intraspecific level. Finally, none of significant difference between T. ngarsuensis and T. shanorum was recognized in morphological characters including diagnostic ones described in the original descriptions. These results strongly suggest that T. ngarsuensis is a junior synonym of T. shanorum.