Phylogeny-based species delimitation in Philippine slender skinks (Reptilia: Squamata: Scincidae: Brachymeles): taxonomic revision of pentadactyl species groups and description of three new species

We use data from external morphology and mitochondrial gene sequences to provide the basis for a taxonomic revision of two polytypic, pentadactyl Philippine species of scincid lizards of the genus Brachymeles. Although previous studies have noted significant morphological variation among island populations, the similarities in body size and scale pigmentation and pattern have led to the continued recognition of these two ‘‘widespread species.’’ A third, widespread, pentadactyl species, Brachymeles talinis, is known from Jolo Island and the central and northern Philippine islands. We evaluate both morphological and genetic data to define species limits in B. boulengeri, B. schadenbergi, and B. talinis. Our molecular and morphological data indicate each of the four subspecies of B. boulengeri, and both subspecies of B. schadenbergi, are genetically distinct, with ranges biogeographically circumscribed, differ from their congeners by numerous external morphological features, and therefore should be recognized as full species. Our morphological and genetic data necessitate the recognition of northern populations of B. talinis (from Luzon Island) as a new species and also reveal an unanticipated new species from Masbate Island. Finally, morphological data require the recognition of the B. talinis population from Jolo Island as a unique, new species. These 10 taxa elevate the total known number of species of Brachymeles from 18 to 25.