The gekkonid genus Cyrtodactylus is the third largest vertebrate genus on the planet with well over 300 species that range across at least eight biogeographic regions from South Asia to Melanesia. The ecological and morphological plasticity within the genus, has contributed to its ability to disperse across ephemeral seaways, river systems, basins, land bridges, and mountain ranges-followed by in situ diversification within specific geographic areas. Ancestral ranges were reconstructed on a mitochondrial phylogeny with 346 described and undescribed species from which it was inferred that Cyrtodactylus evolved in a proto-Himalaya region during the early Eocene. From there, it dispersed to what is currently Indoburma and Indochina during the mid-Eocene-the latter becoming the first major center of origin for the remainder of the genus that seeded dispersals to the Indian subcontinent, Papua, and Sundaland. Sundaland became a second major center of radiation during the Oligocene and gave rise to a large number of species that radiated further within Sundaland and dispersed to Wallacea, the Philippines, and back to Indochina. One Papuan lineage dispersed west to recolonize and radiate in Sundaland. Currently, Indochina and Sundaland still harbor the vast majority of species of Cyrtodactylus.
The purpose of this paper is to solve an overlooked nomenclatural problem involving two taxa of Colubridae, both described as Coluber korros. The first one is Coluber korros Schlegel, 1837, now Ptyas korros, a well-known and widespread species in south-east Asia. Its senior homonym is Coluber korros Lesson, 1831, a long forgotten taxon. Furthermore, these taxa are undoubtedly non-conspecific. We tentatively identify the holotype of this latter taxon as a large specimen of Coelognathus radiatus (F. Boie, 1827) and we specify its type locality as "Region of Kolkata, West Bengal State, eastern India" (the same specification of type-locality can hence be applied to the elapid Naja kaouthia Lesson, 1831). Nevertheless, following the strict principle of priority, Coluber korros Lesson, 1831 has priority over Coluber korros Schlegel, 1837. Based on the Code, we use Article 23.9 on reversal of precedence in order to preserve the use of the well-known taxon Coluber korros Schlegel, 1837 (now Ptyas korros) against its senior primary homonym Coluber korros Lesson, 1831. Finally, we consider Coluber boncorage Lesson, 1831 to be a nomen dubium.
Bronchocela celebensis Gray, 1845 is one of the rarest species of the genus, known only from less than 20 museum specimens collected from northern Sulawesi. It is often confused with its similar congener, B. cristatella, which occurs widely throughout the Indonesian Archipelago and Peninsular Malaysia, except on the Sulawesi mainland. Here, we examine the morphology of B. celebensis based on 46 museum specimens including freshly collected individuals, and redescribe the species based on the holotype (by monotypy). We studied the characters of B. celebensis with morphometric comparison to its allopatric congener B. cristatella from the adjacent islands of southern Sulawesi in Indonesia. Based on the current distribution pattern and the apparent threats, we update the conservation status of B. celebensis using the IUCN Red List Criteria and propose that it be considered as a Vulnerable (VU) species endemic to Sulawesi.
The taxonomic status of Asthenodipsas vertebralis in Borneo has been plagued with uncertainty over the last eighty years. An examination of museum collections resulted in the discovery of a voucher specimen of A. vertebralis from Sarawak, East Malaysia that confirms the presence of the species in Borneo and a previously unrecognised species, Asthenodipsas ingeri sp. nov. from Mount Kinabalu, Sabah. Asthenodipsas ingeri sp. nov. can be differentiated from its congeners by the combination of an absence of preoculars and suboculars, 1st and 3rd pair of infralabials in contact, two pairs of posterior inframaxillaries, supralabials 3-5 (sometimes 3 4) in contact with orbit, 15/15/15 rows of dorsal scales, presence of sharp vertebral keel, and divided subcaudals. This study highlights the importance of careful re-examination of museum collections that could potentially harbour new species hiding in plain sight. These discoveries also add to the growing number of reptile and amphibian species being described from Borneo that shows no signs of abating but are already potentially threatened by the continued deforestation and developments on the island.
We collected two specimens of an undescribed species of Lygosoma from pitfall traps in an urban rainforest in Kuching and from the base of a forested hill in western Sarawak, East Malaysia. The new species is diagnosable from all south-east Asian congeners by morphological characters, and most closely resembles Lygosoma herberti from the Thai-Malay Peninsula. The new species shows substantial molecular divergence from its closest relatives in two protein-coding genes, one mitochondrial (ND1) and one nuclear (R35) that we sequenced for several south-east Asian congeners. We describe the new species on the basis of this distinct morphology and genetic divergence. It is the third species of Lygosoma known from Borneo, and highlights the continuing rise in lizard species diversity on the island. In addition, the discovery of this species from a small urban rainforest underscores the importance of preserving intact rainforest areas of any size in maintaining species diversity.
A new species of Asian rock gecko, genus Cnemaspis, is described from Padawan, western Sarawak, Malaysian Borneo. The new species forms a clade with C. paripari and C. nigridia of the C. nigridia group in a mitochondrial DNA phylogeny and is similar to them morphologically in some characters such as caudal scalation. It differs from the other Asian Cnemaspis species in its unique combination of snout-vent length (up to 62.7 mm), 4-9 precloacal pores in males, keeled subcaudals with an enlarged, smooth, median row, presence of ventrolateral caudal tubercles, and coloration (head and upper flanks dark-yellow; anterior portion of tail black; posterior portion of tail white with black, paravertebral blob). Phylogenetic relationships within the C. nigridia group and the distributional ranges of species within the group suggest allopatric speciation by geographic isolation.
A reassessment of the taxonomy of Lygosoma bampfyldei based on morphology and color pattern indicates that it is a species complex containing L. bampfyldei Bartlett, 1895 from the Rajang River, Sarawak and Croker Range, Sabah in East Malaysia; L. peninsulare sp. nov. from Bukit Larut, Perak and 13.5 km east of Jeli, Kelantan, Peninsular Malaysia; L. kinabatanganensis sp. nov. from the Kinabatangan District, Deramakot camp (=Deramakot Sabah Forestry Department), Sabah, East Malaysia; and L. schneideri Werner, 1900 from Djapura, Indragiri, Sumatra, Indonesia-resurrected herein from the synonymy of L. bampfyldei. The new taxonomy aligns itself well with a growing body of literature demonstrating that semi-fossorial and fossorial Sundaic skinks are more diverse than previously considered.
An integrative taxonomic analysis of the Ptychozoon lionotum group across its range in Indochina and Sundaland recovers P. lionotum sensu lato Annandale, 1905 as paraphyletic with respect to P. popaense Grismer, Wood, Thura, Grismer, Brown, Stuart, 2018a and composed of four allopatric, genetically divergent, ND2 mitochondrial lineages. Multivariate and univariate analyses of continuous and discrete morphological and color pattern characters statistically and discretely diagnose each lineage from one another and together, with maximum likelihood and Bayesian inference analyses, provide the foundation for the recognition of each lineage as a new species-hypotheses corroborated with a Generalized Mixed Yule Coalescent species delimitation analysis. Ptychozoon cicakterbang sp. nov. ranges throughout Peninsular Malaysia to Pulau Natuna Besar, Indonesia; P. kabkaebin sp. nov. is endemic to northern and central Laos; and P. tokehos sp. nov. ranges from southern Thailand south of the Isthmus of Kra northward to Chiang Mai, fringing the Chao Phraya Basin and ranging southward through Cambodia to southern Vietnam. Ptychozoon lionotum sensu stricto ranges from northwestern Laos through southern Myanmar to eastern India. The phylogeographic structure within each species varies considerably with P. lionotum s.s. showing no genetic divergence across its 1,100 km range compared to P. cicakterbang sp. nov. showing upwards of 8.2% sequence divergence between syntopic individuals. Significant phylogeographic structure exists within P. tokehos sp. nov. and increased sampling throughout Thailand may require additional taxonomic changes within this species.
A new species of limestone karst-adapted gecko of the Cyrtodactylus pulchellus complex, C. dayangbuntingensis sp. nov., is described from Dayang Bunting Island of the Langkawi Archipelago off the northwest coast of Peninsular Malaysia. It is the third species of the group to be described from the archipelago after C. langkawiensis and C. macrotuberculatus. The new species can be distinguished from all other species of Cyrtodactylus based on molecular evidence from the mitochondrial gene ND2 and its flanking tRNAs as well as having unique combinations of morphological and color pattern characteristics. This discovery underscores the need for continued surveys of the many islands in the archipelago to properly ascertain its true herpetological diversity.
An integrative taxonomic analysis of Subdoluseps herberti from southern Thailand and Peninsular Malaysia and S. samajaya from Sarawak, East Malaysia (Borneo) recovers the former as paraphyletic with respect to the latter. The analyses recover the three southernmost populations of S. herberti in Peninsular Malaysia as conspecific and the sister lineage of S. samajaya, whereas S. herberti from Thailand and northern Peninsular Malaysia constitute the sister species to S. samajaya plus the southern three Peninsular Malaysian populations. As such, the southern populations are described herein as S. malayana sp. nov. and all three species are referred to as the S. herberti group. Clade boundaries and breaks within this group on the Thai-Malay Peninsula occurring at the Isthmus of Kra, across the Kangar-Pattani line, and between the Thai-Malay Peninsula and Borneo are consistent with phylogeographic patterns of other Sundaic taxa. The discovery of S. malayana sp. nov. continues to underscore the fact that, despite the well-studied nature of the lizard fauna of Peninsular Malaysia, much of it still remains unrealized and for conservation efforts to move forward, field research followed by expeditiously revised taxonomies must continue.
Since the book-formatted, monographic treatment of the lizards of Peninsular Malaysia, Singapore, and their adjacent islands by Grismer (2011), 47 additional species have been added to that fauna bringing the total to 174. One species, Cyrtodactylus stresemanni, was removed from the lizard fauna based on its likely mislabeled type locality; 44 species were described as new-29 gekkonids, 11 scincids, five agamids, and one dibamid; and three others, Cnemaspis narathiwatensis, Cyrtodactylus brevipalmatus, and Scincella melanosticta were recently discovered in northern Peninsular Malaysia. Taxonomic changes for seven previously described species occurring after 2011 are noted and significant, new locality records are documented here for additional species. The intent of this review is to provide an up to date peer-reviewed checklist for the lizard species of this region prior to a pending updated book monograph.
We identified hypotheses for the cause and consequences of the loss of complexity in animal signals and tested these using a genus of visually communicating lizards, the Southeast Asian Draco lizards. Males of some species have lost the headbob component from their display, which is otherwise central to the communication of this genus. These males instead display a large, colorful dewlap to defend territories and attract mates. This dewlap initially evolved to augment the headbob component of the display, but has become the exclusive system of communication. We tested whether the loss of headbobs was caused by relaxed selection, habitat-dependent constraints, or size-specific energetic constraints on display movement. We then examined whether the consequences of this loss have been mitigated by increased signaling effort or complexity in the color of the dewlap. It appears the increased cost of display movement resulting from the evolution of large body size might have contributed to the loss of headbobs and has been somewhat compensated for by the evolution of greater complexity in dewlap color. However, this evolutionary shift is unlikely to have maintained the complexity previously present in the communication system, resulting in an apparent detrimental loss of information potential.
We use data sets from the Cyrtodactylus brevipalmatus group with limited genetic and morphological sampling to demonstrate that not accounting for sampling error may adversely influence decisions regarding species delimitation and diagnosis. Lack of geographic sampling between the endpoints of a species range may recover notable interpopulational genetic differentiation consistent with species-level differentiation. Additionally, small population sample sizes may fail recover statistically different diagnostic morphological differences. Combined, these types of sampling error can produce results seemingly consistent with the recognition of cryptic speciesgenetically delimited populations lacking diagnostic morphological characters. This is the current situation within some lineages of the C. brevipalmatus group whereas in others, sampling error is less problematic and does not jeopardize their taxonomy. We note the potential negative effects for comparative biology as a whole if sampling error is not taken into consideration prior to constructing taxonomies.
Species in the genus Pseudocalotes are generally rare and known only from a few specimens. Pseudocalotes drogon was described based on a single male from Frasers Hill, Pahang, Peninsular Malaysia. During a recent field survey at Frasers Hill, a female specimen was collected and identified as P. drogon based on morphological characters and a molecular phylogenetic analysis. The morphological description of P. drogon is expanded here, based on the male holotype and the newly collected female specimen.
A new species of gekkonid, Hemiphyllodactylus chiangmaiensis sp. nov., from northwestern Thailand is separated from all other species of Hemiphyllodactylus by a set of features including: a maximum SVL of 41.2 mm; 8-12 chin scales extending transversely from unions of second and third infralabials and posterior margin of mental; lamellar formula on hand 3-3-3-3 or 3-4-3-3; lamellar formula on foot 3-3-3-3 or 3-4-4-4; continuous precloacal and femoral pores; a unique dorsal color pattern; and caecum and oviducts pigmented. These characters place this species in the speciose H. typus group. Hemiphyllodactylus chiangmaiensis sp. nov. fills a biogeographical hiatus in the distribution of this genus across northern Indochina.
Cyrtodactylus metropolis sp. nov. from Batu Caves massif, Selangor, Peninsular Malaysia is differentiated from all congeners by having a unique suite of morphological and color pattern characteristics. Remarkably, this species has been overlooked despite a plethora of field studies at Batu Caves from 1898 to the present and no specimens had ever been examined until now. As with all other limestone forest-adapted Cyrtodactylus in Peninsular Malaysia, C. metropolis sp. nov. is not a cave-adapted species but is far more common on the exterior surfaces of the Batu Caves limestone massif and its surrounding limestone vegetation. We suggest that researchers devote time exploring the exterior surfaces of limestone massifs as well the interiors of their caves.
Loss of dispersal typifies island biotas, but the selective processes driving this phenomenon remain contentious. This is because selection via, both indirect (e.g. relaxed selection or island syndromes) and direct (e.g. natural selection or spatial sorting) processes may be involved, and no study has yet convincingly distinguished between these alternatives. Here, we combined observational and experimental analyses of an island lizard, the Komodo dragon (Varanus komodoensis, the world's largest lizard), to provide evidence for the actions of multiple processes that could contribute to island dispersal loss. In the Komodo dragon, concordant results from telemetry, simulations, experimental translocations, mark-recapture, and gene flow studies indicated that despite impressive physical and sensory capabilities for long-distance movement, Komodo dragons exhibited near complete dispersal restriction: individuals rarely moved beyond the valleys they were born/captured in. Importantly, lizard site-fidelity was insensitive to common agents of dispersal evolution (i.e. indices of risk for inbreeding, kin and intraspecific competition, and low habitat quality) that consequently reduced survival of resident individuals. We suggest that direct selection restricts movement capacity (e.g. via benefits of spatial philopatry and increased costs of dispersal) alongside use of dispersal-compensating traits (e.g. intraspecific niche partitioning) to constrain dispersal in island species.
We provide an integrative taxonomic analysis of the Lipinia vittigera species complex from mainland Southeast Asia. Based on examination of external morphology, color pattern, and 681 base pairs of the cytochrome oxidase subunit I (COI) mitochondrial gene, we demonstrate the presence of four morphologically distinct lineages of Lipinia in Vietnam, Cambodia, Thailand, and Malaysia, showing a sequence divergence ranging 15.5%-20.4%. All discovered lineages are discretely diagnosable from one another by a combination of scalation traits and color patterns. A review of the published distribution data and a re-examination of available type material revealed the following results:(1) distribution of L. vittigera (Boulenger, 1894) sensu stricto is restricted to Sundaland and the Thai-Malay Peninsula south of the Isthmus of Kra; (2) L. microcercus (Boettger, 1901) stat. nov. is elevated to full species rank; the species has a wide distribution from central and southern Vietnam across Cambodia to eastern Thailand; we regard Lygosoma vittigerum kronfanum Smith, 1922 and Leiolopisma pranensis Cochran, 1930 as its junior synonyms; (3) Lipinia trivittatasp. nov. occurs in hilly areas of southern Vietnam, Cambodia, and eastern Thailand; and (4) Lipinia vassilievisp. nov. is currently known only from a narrow area along the Vietnamese-Cambodian border in the foothills of the central Annamite Mountain Range. We further provide an identification key for Lipinia occurring in mainland Southeast Asia.
A new insular species Cnemaspis bidongensis sp. nov. (Squamata: Gekkonidae), is described from Pulau Bidong, Terengganu, Peninsular Malaysia and bears a unique suite of morphological and color pattern characters that differentiate it from all other congeners. Cnemaspis bidongensis sp. nov. is the sister species to C. kendallii (Gray) and represents the fifth insular endemic species of Cnemaspis on archipelagos along the east coast of Peninsular Malaysia. This species survived massive deforestation of the small island of Bidong (260 ha) from the mid 1970s to the early 1990s when the island served as a Vietnamese refugee camp and harbored as many as 40,000 people at one time. We hypothesize that this species' generalized lifestyle contributed to its survival, allowing it to seek refuge in rocky microhabitats.