An integrative taxonomic analysis recovers a distinctive new species of the gekkonid genus Cyrtodactylus Gray, 1827 from Satun Province in extreme southern Thailand as the sister species to the Cyrtodactylus intermedius group of southern Indochina, approximately 600 km to the northeast across the Gulf of Thailand. Based on 1449 base pairs of the mitochondrial gene NADH dehydrogenase subunit 2 (ND2) and its flanking tRNAs, the new species, C. disjunctus sp. nov., bears a pairwise sequence divergence from the mean divergences of the intermedius group species ranging from 17.9–23.6%. Three different principal component analyses (PCA) and a multiple factor analysis (MFA) recover C. disjunctus sp. nov. as a highly distinctive karst cave-adapted species based on morphology and color pattern. Its sister species relationship to the intermedius group—to which it is added here—further underscores a growing body of analyses that have recovered a trans-Gulf of Thailand connection across the submerged Sunda Shelf between the southern Thai-Malay Peninsula and southern Indochina. Fragmented karstic archipelagos stretching across Indochina have served as foci for the independent evolution of nearly 25% of the species of Cyrtodactylus. The description of C. disjunctus sp. nov. continues to highlight the fact that karstic habitats support an ever-increasing number of threatened site-specific endemics that compose much of the reptile diversity of many Asian nations but, as of yet, most of these landscapes have no legal protection.

An integrative taxonomic analysis of newly discovered populations of Hemiphyllodactylus from Indochina recovered a new species from Peninsular Thailand and two others from Laos. The new Thai species, Hemiphyllodactylus pardalis sp. nov. described herein, is the sister species to all other species in the newly designated Indochina clade and has a unique spotted contrasting dorsal pattern not seen in any other species of Hemiphyllodactylus. This, along with its elongate and gracile body morphology, renders it remarkably convergent on the Philippine gecko Pseudogekko smaragdinus despite the fact it is deeply nested within Hemiphyllodactylus. The description of this new species underscores the depauperate nature of Hemiphyllodactylus diversity throughout Indochina in general and Thailand in particular compared to neighboring upland areas of Myanmar and Peninsular Malaysia. This especially underscores the need for continued herpetofaunal field surveys in montane areas of western Thailand.

An integrative taxonomic analysis recovered the new species Cnemaspis selenolagus sp. nov. of the C. siamensis group as the sister species to C. punctatonuchalis. The new species was discovered in mountain evergreen tropical forests of in Suan Phueng District of Ratchaburi Province, western Thailand. Additionally, the analysis recovered a deep genetic divergence between northern and southern clades within the C. siamensis group that occur on opposite sides of the Isthmus of Kra—a well-known biogeographic region of cladogenic turnover. The description of C. selenolagus sp. nov. brings the total number of species of Cnemaspis in Thailand to 16, 11 of which compose the C. siamensis group—a lineage endemic to the Thai-Malay Peninsula. This underscores the physiographic complexity of this narrow peninsula in that it can support a large number of closely related species in only the northern two-thirds of its length.

We provide a diversity assessment of the agamid genus Phrynocephalus Kaup, 1825. We analyze COI mtDNA barcodes from 385 individuals sampled all over Phrynocephalus range. We apply the ABGD, ASAP, bGMYC, mlPTP and hsPTP species delimitation algorithms to analyze the COI gene fragment variation and assess the species diversity in Phrynocephalus. Nine species groups are revealed in Phrynocephalus in agreement with earlier studies on the phylogenetic relationships of the genus. We demonstrate that the present taxonomy likely underestimates the actual diversity of the genus. Alternative species delimitation algorithms provide a confusingly wide range of possible number of Phrynocephalus species—from 54 to 103 MOTUs (molecular operational taxonomic units). The ASAP species delimitation scheme recognizing 63 MOTUs likely most closely fits the currently recognized taxonomic framework of Phrynocephalus. We also report on 13 previously unknown Phrynocephalus lineages as unverified candidate species. We demonstrate that the ASAP and the ABGD algorithms likely most closely reflect the actual diversity of Phrynocephalus, while the mlPTP and hsPTP largely overestimate it. We argue that species delimitation in these lizards based exclusively on mtDNA markers is insufficient, and call for further integrative taxonomic studies joining the data from morphology, mtDNA and nuDNA markers to fully stabilize the taxonomy of Phrynocephalus lizards.

A new species of Cyrtodactylus from Tak Province, Thailand, Cyrtodactylus amphipetraeus sp. nov., is described using an integrative taxonomic analysis based on morphology, color pattern, and the mitochondrial gene NADH dehydrogenase subunit 2 (ND2). The phylogenetic analyses place the new species within the C. sinyineensis group which was previously thought to be endemic to the Salween Basin in southern Myanmar. The phylogeny also places C. inthanon in the C. sinyneensis group which is expanded herein to also include the group’s sister species C. doisuthep. Along with C. amphipetraeus sp. nov., these are the first three species of the C. sinyineensis group to be found outside of Myanmar east of the Tenasserim Mountains. The Tenasserim Mountain region is discussed as an area of cladogeneic turnover.

Reptiles are still being described worldwide at a pace of hundreds of species a year. While many discoveries are from remote tropical areas, biodiverse arid regions still harbor many novel taxa. Here, we present an updated phylogeny of colubrid snakes from the Western Palearctic by analyzing a supermatrix of all available global snake species with molecular data and report on the discovery of a new genus and species of colubrine snake from southeastern Iran. The new taxon, named Persiophis fahimii Gen. et sp. nov., is nested within a clade containing Middle Eastern and South Asian ground racers (Lytorhynchus, Rhynchocalamus, Wallaceophis, and Wallophis). This species has a derived morphology including an edentulous pterygoid and occurrence of short and blunt teeth on the palatine, maxillae and dentary bones, an elongated snout and a relatively trihedral first supralabial scale that is slightly bigger than the second, and elongated toward the tip of rostral. We also report on the osteology and phylogenetic placement of several poorly studied colubrines: Hierophis andreanus (reassigned to Dolichophis) and Muhtarophis barani.