Phylogenetic Analysis
Based on previous studies (Li et al. 2009, Hofmann et al. 2017), we identified Scutiger boulengeri containing six clades, for the first time, after max range field works. To construct a phylogeny forS. boulengeri clades, we used MEGA-X (Kumar et al. 2018) to align six selected mtDNA genomes (Genbank MW600725–MW600729 and FJ463132) with genome from outgroup Oreolalax omeimontis (Genbank EU180928). Phylogenetic trees were constructed separately by using maximum likelihood (ML) and Bayesian inference (BI) methods, both of which were implemented in PhyloSuite v1.2.1 (Zhang et al. 2020). The best-fit BIC substitution model (TPM2 + F + G4) was selected in ModelFinder (Kalyaanamoorthy et al. 2017). Divergence time for the reconstructed trees was estimated with the Reltime ML method using MEGA-X (Kumar et al. 2018). Based on previous research, we choose the Most Recent Common Ancestor (MRCA) of Scutiger and Oreolalax(53 Ma) as calibration point (Hofmann et al. 2017).