Integrative taxonomic revision of the Goniurosaurus lichtenfelderi group (Squamata: Eublepharidae): Insights from morphological and molecular data

Understanding the taxonomy of the Goniurosaurus lichtenfelderi group has long been obscured by limited sampling, inconsistent morphological characters, and a lack of publicly available molecular and distribution data. In this study, we conducted the most comprehensive morphological and molecular assessment of this group to date, integrating extensive sampling from Hainan Island and adjacent mainland regions. Phylogenetic analyses using mitochondrial and nuclear genes, along with SNPs delivered from ddRAD-seq, revealed that G. hainanensis is polyphyletic, consisting of two deeply divergent clades (i.e., western and eastern) on Hainan Island. The western clade, from the type locality at Mt. Wuzhi, shows small genetic divergence from G. sinensis (= G. kwanghua), supporting their synonymy. In contrast, the eastern clade is genetically more closely related to the continental G. lichtenfelderi than to its western counterpart. Divergence time estimates further indicate that the eastern and western Hainan populations have distinct evolutionary histories. Based on integrated evidence, we synonymize G. kwanghua and G. sinensis with G. hainanensis, and delimit the eastern Hainan clade as G. cf. lichtenfelderi, pending further morphological confirmation. Consequently, the number of valid species in the G. lichtenfelderi group is revised from five to four (including G. lichtenfelderi, G. hainanensis, G. bawanglingensis, and G. zhoui). In addition, a revised taxonomic account and updated distribution information for all recognized species are provided in this study.