Phylogenetic analyses of distantly related clades of bent-toed geckos (genus Cyrtodactylus) reveal an unprecedented amount of cryptic diversity in northern and western Thailand

A new species of the Cyrtodactyluschauquangensis group (Squamata, Gekkonidae) from the borderlands of extreme northern Thailand

Phylogenetic and morphological analyses delimit and diagnose, respectively, a new population of a karst-dwelling Cyrtodactylus from extreme northern Thailand. The new species, Cyrtodactylusphamiensis sp. nov., of the chauquangensis group inhabits karst caves and outcroppings and karst vegetation in the vicinity of Pha Mi Village in Chiang Rai Province, Thailand. Within the chauquangensis group, Cyrtodactylusphamiensis sp. nov. is the earliest diverging species of a strongly supported clade composed of the granite-dwelling C.doisuthep and the karst-dwelling sister species Cyrtodactylus sp. 6 and C.erythrops. The nearly continuous karstic habitat between the type locality of Cyrtodactylusphamiensis sp. nov. and its close relatives Cyrtodactylus sp. 6 and C.erythrops, extends for approximately 200 km along the border region of Thailand and the eastern limit of the Shan Plateau of Myanmar. Further exploration of this region, especially the entire eastern ~ 95% of the Shan Plateau, will undoubtably recover new populations whose species status will need evaluation. As in all other countries of Indochina and northern Sundaland, the continual discovery of new karst-dwelling populations of Cyrtodactylus shows no signs of tapering off, even in relatively well-collected areas. This only highlights the conservation priority that these unique karstic landscapes still lack on a large scale across all of Asia.

A new species of the Cyrtodactyluschauquangensis species group (Squamata, Gekkonidae) from Lao Cai Province, Vietnam

We describe a new species of the genus Cyrtodactylus based on five adult specimens from Bac Ha District, Lao Cai Province, northern Vietnam. Cyrtodactyluslucisp. nov. is distinguished from the remaining Indochinese bent-toed geckos by a combination of the following morphological characteristics: medium size (SVL up to 89.5 mm); dorsal tubercles in 17-19 irregular transverse rows; ventral scales in 32-34 longitudinal rows at midbody; precloacal pores present in both sexes, 9 or 10 in males, 8 or 9 in females; 12-15 enlarged femoral scales on each thigh; femoral pores 9-12 in males, 5-10 in females; postcloacal tubercles 2-4; lamellae under toe IV 21-23; dorsal pattern consisting of 5 or 6 irregular dark bands, a thin neckband without V-shape or triangle shape in the middle, top of head with dark brown blotches; subcaudal scales transversely enlarged. Molecular phylogenetic analyses recovered the new species as the sister taxon to C.gulinqingensis from Yunnan Province, China, with strong support from all analyses and the two taxa are separated by approximately 8.87-9.22% genetic divergence based on a fragment of the mitochondrial ND2 gene. This is the first representative of Cyrtodactylus known from Lao Cai Province.

Two new karst-adapted species in the Cyrtodactyluspulchellus group (Reptilia, Gekkonidae) from southern Thailand

The exploration of unsurveyed areas in southern Thailand discovered two new karst-adapted species, Cyrtodactylussungaiupesp. nov. and Cyrtodactyluswangkhramensissp. nov., from Thung Wa and La-ngu Districts, Satun Province, respectively. These new species are members of the C.pulchellus group that occur along the Thai-Malay Peninsula. The new species can be distinguished from all other congeners by their key morphological characters and genetic divergence. Morphologically, Cyrtodactylussungaiupesp. nov. and Cyrtodactyluswangkhramensissp. nov. can be diagnosed from other members by having a combination of differences in body size; degree of dorsal tuberculation; absence of tubercles on ventral surfaces; number of ventral scales, paravertebral tubercles and femoroprecloacal pores in males only; deep precloacal groove only in males; absence of a scattered pattern of white dorsal tubercles; number of dark body bands; and the extent of caudal tubercles on an original tail. Although the two species are sister taxa and have nearly identical morphologies, they are considered to be different species, based on a relatively high uncorrected pairwise genetic divergence of the mitochondrial ND2 gene (6.59-6.89%), statistically significant univariate and multivariate morphological differences (PERMANOVA and ANOVA) and diagnostic characteristics of caudal tuberculation on the original tail. Moreover, Cyrtodactylussungaiupesp. nov. and Cyrtodactyluswangkhramensissp. nov. are currently restricted to their karstic type localities which may serve as a geographic barrier to dispersal and gene flow.

A new species of the Cyrtodactylusbrevipalmatus group (Squamata, Gekkonidae) from Tak Province, northwestern Thailand

An integrative taxonomic analysis was used to delimit and diagnose a new species of the Cyrtodactylusbrevipalmatus group from Tak Province in western Thailand. Although Bayesian phylogenetic analyses place C.denticulatussp. nov. within the brevipalmatus group, the new species is neither nested within nor is it the sister species of any other species in the brevipalmatus group. Furthermore, based on the mitochondrial NADH dehydrogenase subunit 2 gene (ND2) and adjacent tRNAs, it bears an uncorrected pairwise sequence divergence of 7.87-21.94% from all other species in the brevipalmatus group. Cyrtodactylusdenticulatussp. nov. is differetiated from all other species in the brevipalmatus group by having a number of unique charateristics such as denticulate ventrolateral body folds and ventrolateral subcaudal ridges, characters not seen in any other species of the group (n = 51 individuals). Additionally, based on a multiple factor anlaysis, C.denticulatussp. nov. does not overlap with any other species in multivariate space. The discovery of C.denticulatussp. nov. underscores the unrealized diversity of upland ecosystems across Thailand and the urgent need for increased exploration and conservation of these unique imperiled montane refugia, especially in this era of climate change.

A new species of the Cyrtodactylus brevipalmatus group (Squamata, Gekkonidae) from the uplands of western Thailand

An integrative systematic analysis recovered a new species of the Cyrtodactylus brevipalmatus group from the uplands of Thong Pha Phum National Park, Kanchanaburi Province in western Thailand. Cyrtodactylus thongphaphumensissp. nov. is deeply embedded within the brevipalmatus group, bearing an uncorrected pairwise sequence divergence of 7.6–22.3% from all other species based on a 1,386 base pair segment of the mitochondrial NADH dehydrogenase subunit 2 gene (ND2) and adjacent tRNAs. It is diagnosable from all other species in the brevipalmatus group by statistically significant mean differences in meristic and normalized morphometric characters as well as differences in categorical morphology. A multiple factor analysis recovered its unique and non-overlapping placement in morphospace as statistically significantly different from that of all other species in the brevipalmatus group. The description of this new species contributes to a growing body of literature underscoring the high degree of herpetological diversity and endemism across the sky-island archipelagos of upland montane tropical forest habitats in Thailand, which like all other upland tropical landscapes, are becoming some of the most imperiled ecosystems on the planet.

A new species in the Cyrtodactylusoldhami group (Squamata, Gekkonidae) from Kanchanaburi Province, western Thailand

Cyrtodactylusmonilatus sp. nov. is described from Si Sawat District, Kanchanaburi Province, in western Thailand. The new species superficially resembles C.zebraicus Taylor, 1962 from southern Thailand. However, differences between the new species from C.zebraicus and other congeners were supported by an integrative taxonomic analysis of molecular and morphological data. Phylogenetic analyses based on the mitochondrial NADH dehydrogenase subunit 2 (ND2) gene showed that the new species is a member of the C.oldhami group and closely related to Cyrtodactylus sp. MT468911 from Thong Pha Phum National Park, Thong Pha Phum District, Kanchanaburi Province. Uncorrected pairwise genetic divergences (p-distances) between the new species and its congeners, including C.zebraicus, ranged from 7.7-17.7%. Cyrtodactylusmonilatus sp. nov. can also be distinguished from all members of the C.oldhami group by having a unique combination of morphological characters, including a snout to vent length of 53.7-63.3 mm in adult males and 58.6-75.8 mm in adult females; 22-34 paravertebral tubercles; 34-42 ventral scales; 30-39 enlarged contiguous femoroprecloacal scales; femoral pores and precloacal pores absent in both sexes; four or five rows of postprecloacal scales; enlarged median subcaudal scales absent; weak ventrolateral folds present; 4-7 rows of paired, paravertebral, dark-brown blotches edged in yellow or yellowish white; and two rows of small, diffuse, yellow or yellowish white spots on flanks. The new species occurs in a narrow range of forest at mid to low elevations associated with karst landscapes in the Tenasserim mountain range.

An integrative taxonomic revision of slug-eating snakes (Squamata: Pareidae: Pareineae) reveals unprecedented diversity in Indochina

Slug-eating snakes of the subfamily Pareinae are an insufficiently studied group of snakes specialized in feeding on terrestrial mollusks. Currently Pareinae encompass three genera with 34 species distributed across the Oriental biogeographic region. Despite the recent significant progress in understanding of Pareinae diversity, the subfamily remains taxonomically challenging. Here we present an updated phylogeny of the subfamily with a comprehensive taxon sampling including 30 currently recognized Pareinae species and several previously unknown candidate species and lineages. Phylogenetic analyses of mtDNA and nuDNA data supported the monophyly of the three genera Asthenodipsas, Aplopeltura, and Pareas. Within both Asthenodipsas and Pareas our analyses recovered deep differentiation with each genus being represented by two morphologically diagnosable clades, which we treat as subgenera. We further apply an integrative taxonomic approach, including analyses of molecular and morphological data, along with examination of available type materials, to address the longstanding taxonomic questions of the subgenus Pareas, and reveal the high level of hidden diversity of these snakes in Indochina. We restrict the distribution of P. carinatus to southern Southeast Asia, and recognize two subspecies within it, including one new subspecies proposed for the populations from Thailand and Myanmar. We further revalidate P. berdmorei, synonymize P. menglaensis with P. berdmorei, and recognize three subspecies within this taxon, including the new subspecies erected for the populations from Laos and Vietnam. Furthermore, we describe two new species of Pareas from Vietnam: one belonging to the P. carinatus group from southern Vietnam, and a new member of the P. nuchalis group from the central Vietnam. We provide new data on P. temporalis, and report on a significant range extension for P. nuchalis. Our phylogeny, along with molecular clock and ancestral area analyses, reveal a complex diversification pattern of Pareinae involving a high degree of sympatry of widespread and endemic species. Our analyses support the "upstream" colonization hypothesis and, thus, the Pareinae appears to have originated in Sundaland during the middle Eocene and then colonized mainland Asia in early Oligocene. Sundaland and Eastern Indochina appear to have played the key roles as the centers of Pareinae diversification. Our results reveal that both vicariance and dispersal are responsible for current distribution patterns of Pareinae, with tectonic movements, orogeny and paleoclimatic shifts being the probable drivers of diversification. Our study brings the total number of Pareidae species to 41 and further highlights the importance of comprehensive taxonomic revisions not only for the better understanding of biodiversity and its evolution, but also for the elaboration of adequate conservation actions.