The taxonomy and phylogeny of the Cyrtodactylus pulchellus complex along the Thai-Malay Peninsular region has been the focus of many recent studies and has resulted in the recognition of 17 species. However, the majority of these studies were focused on Peninsular and insular Malaysia where there were specimens and genetic vouchers. The taxonomic status and phylogenetic relationships of the Thai species in this complex remain unresolved, due to the lack of genetic material of some species, especially C. phuketensis and C. macrotuberculatus from Thai populations. In this study, we investigated the phylogenetic relationship between C. phuketensis and its closely related species C. macrotuberculatus, using both morphometric and molecular data. Phylogenetic analyses of mitochondrial NADH dehydrogenase subunit 2 (ND2) gene revealed that C. phuketensis is embedded within a C. macrotuberculatus clade with 1.45–4.20% (mean 2.63%) uncorrected pairwise sequence divergences. Morphological comparisons showed nearly identical measurements of C. phuketensis and C. macrotuberculatus and overlapping ranges in meristic characters. Based on these data, C. phuketensis is considered to be a variant of C. macrotuberculatus, thus rendering C. phuketensis a junior synonym of C. macrotuberculatus.
Species delimitation and species diagnosis must remain separate operations to avoid constructing taxonomies comprised of non-monophyletic species based on morphological similarity as opposed to phylogenetic propinquity. This is particularly true for highly specialized species such as the range-restricted upland taxa in the Cyrtodactylus brevipalmatus group of Indochina where strong selection pressure for an arboreal lifestyle has contributed to morphologically similar but distantly related species. This in turn, has resulted in a history of erroneous taxonomies that have actually obscured rather than revealed the diversity within this group. A Bayesian phylogeny of the C. brevipalmatus group recovered at least 15 putative species-level lineages, at least seven of which are undescribed, and of which four are described herein. A total evidence morphological data set comprised of 16 normalized morphometric, 15 meristic, and seven categorical characters scored across 51 individuals was subjected to a multiple factor analysis (MFA) and an analysis of variance (ANOVA) to diagnose the putative species. These new species descriptions contribute to focusing attention to the unrealized diversity in upland tropical ecosystems, which due to climate change, are some of the most impearled ecosystems on the planet. Thus, it is paramount that taxonomies do not conflate species identities and underrepresent true diversity.
A new gekkonid lizard, Cyrtodactylus maelanoi sp. nov., from Mae Hong Son Province of the Thai Highlands is described using an integrative taxonomic analysis based on morphology, color pattern, and the mitochondrial gene NADH dehydrogenase subunit 2 (ND2) and its flanking tRNAs. Phylogenetic analyses place the new species within clade 1 of the C. sinyineensis group and as the sister species to C. inthanon with an uncorrected pairwise sequence divergence of 3.9%. Collection data gathered in the field indicate that C. maelanoi sp. nov. is a habitat generalist. Reconstruction of the ancestral habitat preference for the C. sinyineensis group by way of stochasitc character mapping (SCM) indicates that karstic environments were the ancestral condition out of which the general habitat preference of the ancestor of C. maelanoi sp. nov. and C. inthanon and that of C. amphipetreaus and C. doisuthep evolved three times independently. Additionally, SCM demonstrated that the evolution of a granitic habitat preference from a karst-adapted ancestor happened in C. aequalis. The discovery of a new upland species in the Thai Highlands brings into focus the understudied nature of the mountain systems of western Thailand and the need for their continued exploration and conservation.
The bent-toed geckos of the Cyrtodactylus pulchellus group are widely distributed along the Thai-Malay Peninsula. Although taxonomic and phylogenetic studies of this species group have been continuously conducted, only some populations from Thailand have been included, resulting in hidden diversity within this group. In this study, we used morphological and molecular data to clarify the taxonomic status and describe a new population from Tarutao Island, Satun Province, southern Thailand. Cyrtodactylus stellatussp. nov. can be distinguished from its congeners by the combination of the following morphological characters: body size; tuberculation; number of dark body bands, ventral scales, and femoroprecloacal pores in males; presence of precloacal pores in females; and scattered pattern on dorsum. Phylogenetic analyses of the mitochondrial ND2 gene recovered the new species as the sister species to C. astrum, with an uncorrected pairwise divergence of 9.78–12.37%. Cyrtodactylus stellatussp. nov. is currently only known from Tarutao Island, Thailand. The discovery of this species suggests that the diversity within the C. pulchellus group remains underestimated and future exploration of unsurveyed areas are needed to further the understanding of this group and its geographic range.
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