Hidden diversity of rock geckos within the species group (Gekkonidae, Squamata): genetic and morphological data from southern Thailand reveal two new insular species and verify the phylogenetic affinities of and .

Two new insular rock geckos in the genus are described from Ko Samui in Surat Thani Province and Ko Similan in Phang-nga Province, southern Thailand, based on a combination of morphological and mitochondrial NADH dehydrogenase subunit 2 (ND2) data. Both new species represent divergent lineages within the species group. is distinguished from other species in the group by having eight or nine supralabial and infralabial scales; 5-8 pore-bearing precloacal scales in males, pores rounded; 25-27 paravertebral tubercles, arranged randomly; 22-25 subdigital lamellae under 4 toe; enlarged median subcaudal scale row present; gular region, abdomen, limbs and subcaudal region yellowish only in males, and uncorrected pairwise divergences of 8.86-26.83% from all other species in the species group. is distinguished from other species in the group by having eight or nine supralabial and seven or eight infralabial scales; one pore-bearing precloacal scale in males, pore rounded; 24 or 25 paravertebral tubercles, arranged randomly; 23 or 24 subdigital lamellae under 4 toe; no enlarged median subcaudal scale row; pale yellow reticulum on head, neck, flanks, belly and limbs in male only, and uncorrected pairwise divergences of 9.34-27.11% from all other species in the species group. is found along granitic rocky stream outcrops of Hin Lad Waterfall, Ko Samui, Gulf of Thailand, while occurs in granitic rocky outcrops near Ao Nguang Chang Bay, Ko Similan, Andaman Sea. The phylogenetic analyses confirmed that and are also nested within the species group, as previously hypothesized from morphology and color pattern characters.