A New Isosporan (Apicomplexa: Eimeriidae) from the Pacific Blue-Tailed Skink, Emoia caeruleocauda (Sauria: Scincidae: Eugongylinae), from Guam, U.S. Territory.

PURPOSE: Nothing is known about coccidians (Apicomplexa: Eimeriidae) from the Pacific blue-tailed skink, Emoia caeruleocauda. Here, we report mensural and morphometric data on a new species of Isospora from E. caeruleocauda from Guam, US Territory. METHODS: Feces from four E. caeruleocauda collected by hand in November 2023 were placed in individual vials containing 2.5% potassium dichromate. They were examined for sporulated oocysts after flotation in Sheather's sugar solution, measured, and photographed. RESULTS: A single (25%) E. caeruleocauda was found to be passing oocysts representing a new species of Isospora. Oocysts of Isospora guamensis n. sp. are ellipsoidal to ovoidal with a bi-layered wall, measure (L × W) 16.5 × 11.8 µm, and have a length/width (L/W) ratio of 1.4; a micropyle and an oocyst residuum were absent but a polar granule was present. Sporocysts are ovoidal and measure 9.4 × 6.5 µm, L/W 1.4; Stieda and sub-Stieda bodies were present but a para-Stieda body was absent. The sporocyst residuum is composed various-sized granules in a compact rounded or irregular mass, sometimes dispersed between the sporozoites. The new species can be differentiated from all other isosporans from skinks by possessing the smallest oocysts known from this host family. CONCLUSION: This is the first time an isosporan coccidian has been reported from E. caeruleocauda as well as the first report of a coccidian from a Guam-inhabiting skink.

The natural and human-mediated expansion of a human-commensal lizard into the fringes of Southeast Asia.

BACKGROUND: Human-commensal species often display deep ancestral genetic structure within their native range and founder-effects and/or evidence of multiple introductions and admixture in newly established areas. We investigated the phylogeography of Eutropis multifasciata, an abundant human-commensal scincid lizard that occurs across Southeast Asia, to determine the extent of its native range and to assess the sources and signatures of human introduction outside of the native range. We sequenced over 350 samples of E. multifasciata for the mitochondrial ND2 gene and reanalyzed a previous RADseq population genetic dataset in a phylogenetic framework. RESULTS: Nuclear and mitochondrial trees are concordant and show that E. multifasciata has retained high levels of genetic structure across Southeast Asia despite being frequently moved by humans. Lineage boundaries in the native range roughly correspond to several major biogeographic barriers, including Wallace's Line and the Isthmus of Kra. Islands at the outer fringe of the range show evidence of founder-effects and multiple introductions. CONCLUSIONS: Most of enormous range of E. multifasciata across Southeast Asia is native and it only displays signs of human-introduction or recent expansion along the eastern and northern fringe of its range. There were at least three events of human-introductions to Taiwan and offshore islands, and several oceanic islands in eastern Indonesia show a similar pattern. In Myanmar and Hainan, there is a founder-effect consistent with post-warming expansion after the last glacial maxima or human introduction.

Built for success: Distribution, morphology, ecology and life history of the world's skinks.

In animals, the success of particular lineages can be measured in terms of their number of species, the extent of their geographic range, the breadth of their habitats and ecological niches, and the diversity of their morphological and life-history traits. Here, we review the distribution, ecology, morphology and life history of skinks, a diverse lineage of terrestrial vertebrates. We compared key traits between the three subfamilies of skinks, and between skinks and non-scincid lizards. There are currently 1743 described species of skink, which represent 24% of global lizard diversity. Since 2010, 16% of lizard descriptions have been of skinks. The centres of skink diversity are in Australia, New Guinea, southeast Asia, Oceania, Madagascar and central Africa. Compared with non-scincid lizards, skinks have larger distributional ranges, but smaller body sizes. Sexual size dimorphism is rare in skinks. Almost a quarter (23%) of skinks exhibit limb reduction or loss, compared with just 3% of non-scincid lizards. Skinks are more likely to be viviparous (34% of species) compared with non-scincids (13%), and have higher clutch/litter sizes than non-scincids. Although skinks mature later than non-scincids, their longevity is similar to that exhibited by other lizard groups. Most skinks (88%) are active foragers, and they are more likely to be carnivorous than non-scincids. Skinks are more likely to be diurnal or cathemeral than other lizard groups, but they generally have lower field body temperatures compared with non-scincids. The success of skinks appears to be both a result of them hitting upon a winning body plan and ecology, and their capacity to regularly deviate from this body plan and adapt their ecology and life history (e.g. repeated limb reduction and loss, transitions to viviparity) to prevailing conditions.

Redescription of Thubunaea schukurovi Annaev, 1973 from Ablepharus chernovi, with notes on the members of Thubunaea (Spirurida: Physalopteridae) from the Palaearctic and Indomalayan realms.

The spirurid nematode Thubunaea schukurovi Annaev, 1973 (Physalopteridae) is redescribed by means of light microscopy and scanning electron microscopy from Ablepharus chernovi collected in Çamliyayla, Turkey. This is the first record of the species from this host and the first record of the genus Thubunaea from Turkey. The taxonomic status of the species of the genus Thubunaea from the Palaeacrtic and Indomalayan realms is reviewed based on their original morphological descriptions; as a result, Thubunaea dessetae Barus & Tenora, 1976, a parasite of Saara hardwickii (Gray) (Agamidae) in Afghanistan, is transferred to the genus Pseudabbreviata as Pseudabbreviata dessetae (Barus & Tenora, 1976) n. comb. Several species described in India, that is, Thubunaea singhi Deshmukh, 1969 and Thubunaea brooki Deshmukh, 1969, both from Hemidactylus brookii Gray (Gekkonidae), and Thubunaea aurangabadensis Deshmukh, 1969 and Thubunaea syedi Deshmukh, 1969, both from Hemidactylus giganteus Stoliczka, are considered members of the genus Physalopteroides; therefore, the following new combinations are proposed: Physalopteroides singhi, Physalopteroides brooki, Physalopteroides aurangabadensis and Physalopteroides syedi. Thubunaea hemidactylae Oshmarin & Demshin, 1972 from Hemidactylus frenatus Duméril & Bibron in Vietnam is considered a member of the genus Physalopteroides as P. hemidactylae (Oshmarin & Demshin, 1972) n. comb.

Activity patterns and reproductive behavior of the Critically Endangered Bermuda skink (Plestiodon longirostris).

The study of rare or cryptic species in zoos can provide insights into natural history and behavior that would be difficult to obtain in the field. Such information can then be used to refine population assessment protocols and conservation management. The Bermuda skink (Plestiodon longirostris) is an endemic Critically Endangered lizard. Chester Zoo's successful conservation breeding program is working to safeguard, increase and reinforce skink populations in the wild. A key aim of this program is to develop our understanding of the behavior of this species. In this study, using 24 h video recordings, we examined the daily activity patterns, basking behavior and food preferences of four pairs of Bermuda skinks. The skinks displayed a bimodal pattern of activity and basking, which may have evolved to avoid the strength of the midday sun in exposed habitats in Bermuda. Captive Bermuda skinks appear to prefer a fruit-based diet to orthopteran prey. We also documented their reproductive behavior and compared it against two closely related species. Although there were many similarities between the courtship and mating behaviors of the three species, there was a significantly shorter period of cloacal contact in the Bermuda skink. Oophagia was also documented for the first time in this species. This knowledge has enabled the evaluation of the current ex-situ management practices of this species, filled gaps in knowledge that would be challenging to obtain in the field, and enabled the enhancement of both animal husbandry and reproductive success for the conservation breeding program.

New host and locality records of helminths' infection of seven lizards from Morocco.

Morocco has a great diversity of reptiles; more than 26% of the herpetofauna species are considered to be endemic. Nevertheless, there is little information available on helminth parasites of Moroccan lizards. The purpose of this article is to establish a helminth list using non-invasive methods for natural populations of seven lizard species: Acanthodactylus maculatus, Chalcides mionecton, Chalcides montanus, Chalcides polylepis, Quedenfeldtia moerens, Quedenfeldtia trachyblepharus, and Tarentola mauritanica. For each species, prevalence and intensity of infection were given as well as their relationship to some determinant parameters (sex, age class, size, altitude, and seasons). Four species of nematodes, Parapharyngodon micipsae, Pharyngodon mamillatus, Spauligodon auziensis, Thelandros alatus, and unassigned Spauligodon were found. Mean helminth intensity for the seven lizard species was 7.3 ± 16.2 SD (range = 1-92 in infected lizards), with total infection prevalence of 5.6%. Mixed infections were observed in Chalcides montanus and Chalcides polylepis co-infected by Pharyngodon mamillatus and Spauligodon sp. Furthermore, the intensity of infection by nematodes were significantly different among the seven studied species. The nematode infection in Chalcides mionecton were related to sex, host size, and altitude; in Chalcides polylepis to the host age; in Quedenfeldtia trachyblepharus to elevation, age, and host size; and in Tarentola Mauritanica to age, body size, seasons, and altitude. In conclusion, our study provides data about nine new host and locality records and the effect of some determinant factors on host parasitism.

Enhanced short-wavelength sensitivity in the blue-tongued skink Tiliqua rugosa.

Despite lizards using a wide range of colour signals, the limited variation in photoreceptor spectral sensitivities across lizards suggests only weak selection for species-specific, spectral tuning of photoreceptors. Some species, however, have enhanced short-wavelength sensitivity, which probably helps with the detection of signals rich in ultraviolet and short wavelengths. In this study, we examined the visual system of Tiliqua rugosa, which has an ultraviolet/blue tongue, to gain insight into this species' visual ecology. We used electroretinograms, opsin sequencing and immunohistochemical labelling to characterize whole-eye spectral sensitivity and the elements that shape it. Our findings reveal that T. rugosa expresses all five opsins typically found in lizards (SWS1, SWS2, RH1, RH2 and LWS) but possesses greatly enhanced short-wavelength sensitivity compared with other diurnal lizards. This enhanced short-wavelength sensitivity is characterized by a broadening of the spectral sensitivity curve of the eye towards shorter wavelengths while the peak sensitivity of the eye at longer wavelengths (560 nm) remains similar to that of other diurnal lizards. While an increased abundance of SWS1 photoreceptors is thought to mediate elevated ultraviolet sensitivity in a couple of other lizard species, SWS1 photoreceptor abundance remains low in this species. Instead, our findings suggest that short-wavelength sensitivity is driven by multiple factors which include a potentially red-shifted SWS1 photoreceptor and the absence of short-wavelength-absorbing oil droplets. Examining the coincidence of enhanced short-wavelength sensitivity with blue tongues among lizards of this genus will provide further insight into the co-evolution of conspecific signals and whole-eye spectral sensitivity.

Pharyngodon mamillatus (Nematoda: Pharyngodonidae) in the ocellated skink Chalcides ocellatus (Squamata: Scincidae) from Egypt: Light and scanning electron microscopic studies.

Twenty-one Pharyngodon mamillatus were recovered from the large intestine of 4 out of 12 ocellated skink Chalcides ocellatus collected from the South Sinai desert, Egypt. The prevalence of infection was 33.33% (intensity 2-4). The recovered pharyngodonid was re-described based on light and scanning electron microscopy. According to the morphology, it was characterized by regular transverse annulations extending from the posterior margin of the lips to the level of the anus, triangular mouth opening was surrounded by three large bilobed lips possessing three papillae, oval-shaped excretory pore, slit-like vulva opening, and slit-like anal ventral opening at the posterior end which terminates with a tail filament. Here, the morphometric measurements of adult female P. mamillatus were given in this study. It has no intraspecific morphological variations from the previously described P. mamillatus, but it appeared with small range on biometric features. These variations may be accounted by host/environment attributes since they exhibit wide host and geographical spectra. The present study was applied for detailed morphological knowledge of the recovered P. mamillatus for strengthening their taxonomic validity. HIGHLIGHTS: The Pharyngodon mamillatus naturally parasite of the intestinal region of Chalcides ocellatus. The present study clarifies the morphological key for the description of P. mamillatus.

Evolution of diel activity patterns in skinks (Squamata: Scincidae), the world's second-largest family of terrestrial vertebrates.

Many animals have strict diel activity patterns, with unique adaptations for either diurnal or nocturnal activity. Diel activity is phylogenetically conserved, yet evolutionary shifts in diel activity occur and lead to important changes in an organism's morphology, physiology, and behavior. We use phylogenetic comparative methods to examine the evolutionary history of diel activity in skinks, one of the largest families of terrestrial vertebrates. We examine how diel patterns are associated with microhabitat, ambient temperatures, and morphology. We found support for a nondiurnal ancestral skink. Strict diurnality in crown group skinks only evolved during the Paleogene. Nocturnal habits are associated with fossorial activity, limb reduction and loss, and warm temperatures. Our results shed light on the evolution of diel activity patterns in a large radiation of terrestrial ectotherms and reveal how both intrinsic biotic and extrinsic abiotic factors can shape the evolution of animal activity patterns.

De novo Assembly, Annotation, and Analysis of Transcriptome Data of the Ladakh Ground Skink Provide Genetic Information on High-Altitude Adaptation.

The Himalayan Arc is recognized as a global biodiversity hotspot. Among its numerous cryptic and undiscovered organisms, this composite high-mountain ecosystem harbors many taxa with adaptations to life in high elevations. However, evolutionary patterns and genomic features have been relatively rarely studied in Himalayan vertebrates. Here, we provide the first well-annotated transcriptome of a Greater Himalayan reptile species, the Ladakh Ground skink Asymblepharus ladacensis (Squamata: Scincidae). Based on tissues from the brain, an embryonic disc, and pooled organ material, using pair-end Illumina NextSeq 500 RNAseq, we assembled ~77,000 transcripts, which were annotated using seven functional databases. We tested ~1600 genes, known to be under positive selection in anurans and reptiles adapted to high elevations, and potentially detected positive selection for 114 of these genes in Asymblepharus. Even though the strength of these results is limited due to the single-animal approach, our transcriptome resource may be valuable data for further studies on squamate reptile evolution in the Himalayas as a hotspot of biodiversity.

The complete mitochondrial genome of Asymblepharus himalayanus (Scincidae; Sauria) and its phylogenetic position within Scincidae.

The complete mitochondrial genome of Asymblepharus himalayanus, has been determined for the first time by sanger sequencing. The overall length of the mitogenome is 17,304 bp and contains 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a putative control region. The total base composition is 31.2% for A, 27.0% for T, 14.4% for G, and 27.4% for C. The phylogenetic tree with the whole mitochondrial genome sequence of A. himalayanus together with 10 other related species belonging to the family Scincidae was reconstructed, in order to prove the validity of the mitogenome of A. himalayanus. Phylogenetic analysis indicated that A. himalayanus was not nested within Scincella, and further corroborated this species does not belong to the genus of Scincella.

A new species of Proegernia from the Namba Formation in South Australia and the early evolution and environment of Australian egerniine skinks.

The diverse living Australian lizard fauna contrasts greatly with their limited Oligo-Miocene fossil record. New Oligo-Miocene fossil vertebrates from the Namba Formation (south of Lake Frome, South Australia) were uncovered from multiple expeditions from 2007 to 2018. Abundant disarticulated material of small vertebrates was concentrated in shallow lenses along the palaeolake edges, now exposed on the western of Lake Pinpa also known from Billeroo Creek 2 km northeast. The fossiliferous lens within the Namba Formation hosting the abundant aquatic (such as fish, platypus Obdurodon and waterfowl) and diverse terrestrial (such as possums, dasyuromorphs and scincids) vertebrates and is hereafter recognized as the Fish Lens. The stratigraphic provenance of these deposits in relation to prior finds in the area is also established. A new egerniine scincid taxon Proegernia mikebulli sp. nov. described herein, is based on a near-complete reconstructed mandible, maxilla, premaxilla and pterygoid. Postcranial scincid elements were also recovered with this material, but could not yet be confidently associated with P. mikebulli. This new taxon is recovered as the sister species to P. palankarinnensis, in a tip-dated total-evidence phylogenetic analysis, where both are recovered as stem Australian egerniines. These taxa also help pinpoint the timing of the arrival of scincids to Australia, with egerniines the first radiation to reach the continent.

The first complete mitochondrial DNA of the Chinese short-limbed skink (Ateuchosaurus chinensis Gray, 1845) determined by next-generation sequencing.

The complete mitochondrial DNA (mtDNA) for the Chinese short-limbed skink (Ateuchosaurus chinensis Gray, 1845) was described by using next-generation sequencing. The total length of mtDNA was 16,840 bp, which contained 13 PCGs (COI-III, ND1-6, ND4L, ATP6, ATP8, and CYTB), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes, and a control region (D-loop). The Bayesian inference tree showed that A. chinensis was a sister taxon to other scincid lizards in genera of Scincella, Isopachys, Sphenomorphus and Tropidophorus. The complete mtDNA of A. chinensis will be an important genetic resource to the studies of conservation and restoration of A. chinensis.

Description and Molecular Differentiation of a New Skrjabinoptera (Nematode: Physalopteridae) from Eutropis macularia (Sauria: Scincidae) in North-Central Vietnam.

Skrjabinoptera vietnamensis n. sp. is described from specimens recovered from the stomach of Eutropis macularia in north-central Vietnam. The new species is characterized by the medium-sized male worms (6.7-8.7 mm in length and 154-182 µm in width) relative to known members of the genus, 2 pointed spicules of unequal length (87-112 µm and 56-72 µm in length), and 10 pairs of caudal papillae. Female worms are larger than male worms (10.7-18.4 mm in length and 264-411 µm in width), with the vulva situated in the anterior part, and embryonated, elliptical eggs, 35-46 µm long by 20-24 µm wide. Skrjabinoptera vietnamensis n. sp. represents the ninth species assigned to the genus and the first species recorded from the Oriental region. Partial sequences of the 18S ribosomal RNA gene (rDNA), and cytochrome c oxidase subunit 1 (COI) are provided for the new species. The molecular phylogenetic position of the genus Skrjabinoptera is briefly discussed.

Elevation is a stronger predictor of morphological trait divergence than competition in a radiation of tropical lizards.

Adaptations for efficient performance are expected to shape animal morphology based on selection for microhabitat use and ecological forces. The presence of competitor species is predicted to cause niches to contract and enhance trait divergence. Therefore, increased species richness is expected to lead to greater trait divergence, and to result in reduced overlap and similarity between morphologies of sympatric species. We examined patterns of morphospace occupancy and partitioning in the skink fauna of New Guinea, the world's largest tropical island. Because skink species richness is largely decoupled from elevation in New Guinea, we could examine the effects of both factors (as proxies for competition and abiotic conditions), on morphospace occupancy and partitioning. We measured 1,860 specimens from 79 species of skinks throughout Papua New Guinea, and examined their morphospace occupancy in a spatial context. We calculated, for each assemblage within equal-area cells, the volume of morphospace occupied by all skinks, the mean volume occupied per species, and the mean distance and overlap between all species pairs. We then examined whether these metrics are related to species richness and elevation. Elevation is a stronger predictor of morphospace occupancy than species richness. As elevation increases, intraspecific variation decreases and morphologies become more similar to each other such that overall morphospace occupancy decreases. Highland skinks are, on average, smaller, thinner and shorter limbed than lowland species. We hypothesise that harsh climates in the New Guinea highland habitats impose strong selection on skinks to occupy specific areas of morphospace that facilitate efficient thermoregulation in suboptimal thermal conditions. We conclude that the effect of competition on trait divergence on a community and assemblage scale is eclipsed by abiotic selection pressures in these harsh environments.

Complete mitochondrial genome of a blue-tailed skink Plestiodon capito (Reptilia, Squamata, Scincidae) and comparison with other Scincidae lizards.

Vertebrate mitochondrial genomes (mitogenomes) are valuable for studying phylogeny, evolutionary genetics and genomics. To date, however, compared to other vertebrate groups, our knowledge about the mitogenomes of skinks (the family Scincidae), even of reptile, has been relatively limited. In the present study, we determined the complete mitogenome of a blue-tailed skink Plestiodon capito for the first time, and compared it with other skinks available in GenBank. The circular genome is 17,344 bp long, showing a typical vertebrate pattern with 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes and one control region (CR). The gene organization, nucleotide composition, and codon usage are similar to those from skinks previously published. Twelve out of 13 PCGs initiates with canonical start codon (ATG), while COX1 starts with GTG. The codon usage analysis revealed a preferential use of the LeuCUN (Leu1), Pro, and Thr codons with the A/U ending. All tRNAs in P. capito were predicted to fold into typical clover-leaf secondary structure, except tRNA-Ser AGY. The secondary structures of 12S rRNA and 16S rRNA comprises 34 helices and 56 helices, respectively. The alignment of the Plesitodon species CRs exhibited high genetic variability and rich A + T content. Besides, variable types and numbers of tandem repeat units were also identified in the CR of Plestiodon. Phylogenetic analyses recovered P. capito as the sister species to P. tunganus; monophyly of the Scincidae is well supported. Our results will help to better understand structure and evolution of the mitochondrial DNA control region in reptiles as well as the evolutionary status of P. capito, and to lay foundation for further phylogenetic study of skinks in a mitogenomic framework.

Plasma estradiol and progesterone concentrations during the female reproductive cycle in a highly placentotrophic viviparous lizard, Mabuya sp.

The neotropical genus Mabuya are obligate placentotrophic viviparous lizards, which have a short vitellogenesis that produces microlecithal oocytes and a prolonged time of gestation (9 to 10 months). The hormonal control of female reproductive activity during follicular growth and pregnancy has not been studied, although it is known that the corpus luteum can produce progesterone, but regresses early in pregnancy, being replaced in this function by the placenta. Through enzyme immunoassay (EIA) we measured the plasma concentrations of estradiol (E2) and progesterone (P4) in females of a population of Mabuya sp at different stages of their reproductive cycle. Previously, we confirmed the presence of P4 in plasma by high-performance liquid chromatography methods with diode-array detector ultraviolet (HPLC-DAD-UV). The average concentration values of E2 and P4 were compared among reproductive stages and their dynamics were related to what is known in other oviparous and viviparous amniotes. The plasma E2 concentrations of Mabuya sp. are below the levels found in other viviparous reptiles, probably related to the substantial reduction of its follicular growth phase. Its highest concentration was detected during vitellogenesis, related to its function in the growth and maturation of the ovarian follicles and oviduct preparation for pregnancy; lower levels were observed during pregnancy, but they increase at the end when a new vitellogenesis event begins and massive placental maternal-fetal nutrient transfer occurs. High concentrations of P4 were found during pregnancy, related to its function in the maintenance of the developing embryos within the oviduct. The highest levels of P4 were found at early gestation, then they descend from mid-gestation to the end of gestation. Although some characteristics of hormonal control related to the high level of placentotrophy were observed in this species, the changes in plasma sex steroid concentrations during the reproductive cycle in females of Mabuya sp. follow patterns seen in other viviparous amniotes.

Comparative study of the visual system of two psammophilic lizards (Scincus scincus &Eumeces schneideri).

Sand deserts are common biotopes on the earth's surface. Some specialized vertebrate species have colonized these ecological habitats by living buried in the sand. Among these so called psammophilic species are the Scincidae sand dune living species Scincus scincus and Eumeces schneideri. These two skinks share a relatively similar behavioral ecology by living buried in sand, almost all the time for S. scincus and at least for some part of the day for E. schneideri. The visual system of these two lizards was investigated by histological, immunohistochemical, Magnetic Resonance Imaging (MRI) and morphometric techniques. Both skink species exhibit a retina lacking fovea, composed predominantly of cones presenting two types of oil droplets (pale blue-green and colorless). Both species possess a subset of rod like-photoreceptors (about 1 rod for 30 cones) evidenced by anti-rhodopsin immunoreactivity. A ratio 1:1-1:2 between ganglion cells and photoreceptors points to a linear connection (photoreceptors/bipolar neurons/ganglion cells) in the retina and indicates that both skinks more likely possess good visual acuity, even in the peripheral retina. The MRI analysis revealed differences between the species concerning the eye structures, with a more spherical eye shape for S. scincus, as well as a more flattened lens. The relative lens diameter of both species seems to correspond to a rather photopic pattern. Beside the fact that S. scincus and E. schneideri have different lifestyles, their visual capacities seem similar, and, generally speaking, these two psammophilic species theoretically exhibit visual capacities not far away from non-fossorial species.

New Zealand forest-dwelling skinks of the Oligosoma oliveri (McCann) species-complex (Reptilia: Scincidae): reinstatement of O. pachysomaticum (Robb) and an assessment of historical distribution ranges.

The forest-dwelling skinks of the Oligosoma oliveri ('marbled skink') species-complex, from the North Island of New Zealand, have proven difficult taxonomically because all mainland populations are extinct, obscuring patterns of distribution and population interaction. Twenty-four small insular populations have survived off the north-east coast of the North Island, which are at present classified into three species. In this paper I re-assess the available phenotypic, ecological, biogeographic and phylogenetic evidence associated with these skinks. As a result, O. pachysomaticum (Robb) is raised from synonymy with O. oliveri (McCann) and more precise historical distribution limits are inferred for each member of the group. Implications for the conservation management of each species are also discussed.

Integrative taxonomy of the Asian skinks Sphenomorphus stellatus (Boulenger, 1900) and S. praesignis (Boulenger, 1900) with the resurrection of S. annamiticus (Boettger, 1901) and the description of a new species from Cambodia.

Molecular phylogenetic analyses of the sister species Sphenomorphus stellatus and S. praesignis based on the mitochondrial genes 12S and 16S rRNA recover the former as paraphyletic with respect to the latter in that a specimen of S. stellatus from the type locality in Peninsular Malaysia is more closely related to S. praesignis than to Indochinese populations of S. stellatus. Furthermore, the phylogeny indicates that the Indochinese populations represent two species, thus resulting in four major lineages within this clade. These relationships are consistent with multivariate and univariate analyses of morphological and discrete color pattern data which statistically define and diagnose the four lineages and together with the molecular data, provide the foundation for robust, testable, species-level hypotheses. As such, S. stellatus is herein restricted to Peninsular Malaysia; S. annamiticus is resurrected for the circum-continental populations ranging through southeastern Thailand, southern Cambodia, and southern Vietnam; a new species-S. preylangensis sp. nov.-is described from an isolated mountain, Phnom Chi, from the Prey Lang Wildlife Sanctuary in central Cambodia; and the taxonomy of S. praesignis remains unchanged. The description of S. preylangensis sp. nov. underscores the necessity to conserve this remnant of lowland evergreen rainforest in the Prey Lang Wildlife Sanctuary.