A review of the genus Trachylepis (Sauria: Scincidae) from the Gulf of Guinea, with descriptions of two new species in the Trachylepis maculilabris (Gray, 1845) species complex.

The scincid genus Trachylepis is represented in the oceanic islands of the Gulf of Guinea by four species, Trachylepis maculilabris, T. affinis, T. adamastor and T. ozorii. Here we describe two new species, Trachylepis thomensis sp. nov., endemic to São Tomé Island and Rolas Islet, and Trachylepis principensis sp. nov., endemic to Príncipe Island. Phylogenetic analysis using the mitochondrial gene 16S shows that both new species are genetically divergent and reciprocally monophyletic, and confirms evidence for the uniqueness of these lineages presented in previous studies. Morphological data (scalation and morphometry) identify consistent phenotypic differences between these two island species. We were also able to confirm that the T. affinis population of Príncipe Island is conspecific with the African mainland population and most probably the result of recent introductions. These findings raise the number of known Trachylepis species in the Gulf of Guinea islands group to five, four of which are endemic, although the phylogenetic and phylogeographic relationships of T. adamastor and T. ozorii remain unknown and require further investigation.