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Emerging and re‐emerging pathogens often stem from zoonotic origins, cycling between humans and animals, and are frequently vectored and maintained by hematophagous arthropod vectors. The efficiency by which these disease agents are successfully transmitted between vertebrate hosts is influenced by many factors, including the host on which a vector feeds. The Lyme disease bacterium Borrelia burgdorferi sensu lato has adapted to survive in complex host environments, vectored by Ixodes ticks, and maintained in multiple vertebrate hosts. The versatility of Lyme borreliae in disparate host milieus is a compelling platform to investigate mechanisms dictating pathogen transmission through complex networks of vertebrates and ticks. Squamata, one of the most diverse clade of extant reptiles, is comprised primarily of lizards, many of which are readily fed upon by Ixodes ticks. Yet, lizards are one of the least studied taxa at risk of contributing to the transmission and life cycle maintenance of Lyme borreliae. In this review, we summarize the current evidence, spanning from field surveillance to laboratory infection studies, supporting their contributions to Lyme borreliae circulation. We also summarize the current understanding of divergent lizard immune responses that may explain the underlying molecular mechanisms to confer Lyme spirochete survival in vertebrate hosts. This review offers a critical perspective on potential enzootic cycles existing between lizard‐tick‐Borrelia interactions and highlights the importance of an eco‐immunology lens for zoonotic pathogen transmission studies. [ABSTRACT FROM AUTHOR]

Reptiles are known to be asymptomatic carriers of various zoonotic pathogens. A number of Gram-negative opportunistic commensals are causative agents of bacterial infections in immunocompromised or stressed hosts and are disseminated by reptiles, whose epidemiological role should not be neglected. Since most studies have focused on exotic species, in captivity or as pet animals, the role of wild populations as a potential source of pathogens still remains understudied. In the present study, we isolated a variety of Gram-negative bacteria from the cloacal microbiota of free-living lizard and tortoise hosts (Reptilia: Sauria and Testudines) from the Bulgarian herpetofauna. We evaluated their pathogenic potential according to their antibiotic susceptibility patterns, biofilm-forming capacity, and extracellular production of some enzymes considered to play roles as virulence factors. To our knowledge, the phenotypic manifestation of virulence factors/enzymatic activity and biofilm formation in wild reptile microbiota has not yet been widely investigated. All isolates were found to be capable of forming biofilms to some extent and 29.6% of them could be categorized as strong producers. Two strains proved to be excellent producers. The majority of the isolated strains showed extracellular production of at least one exoenzyme. The most pronounced pathogenicity could be attributed to the newly isolated Pseudomonas aeruginosa strain due to its multiresistance, excellent biofilm formation, and expression of exoenzymes. [ABSTRACT FROM AUTHOR]

Color and pattern are often critical to survival and fitness, but we know little about their genetic architecture and heritability in groups like reptiles. We investigated the genetic architecture for the pattern of the dewlap—an extensible throat fan important for communication—in anole lizards. We studied the Hispaniolan bark anole (Anolis distichu s)—a species that exhibits impressive intraspecific dewlap polymorphism across its range—by conducting multigenerational experimental crosses with 2 populations, one with a solid pale yellow dewlap and another with an orange dewlap surrounded by a yellow margin. Upon rejecting the hypothesis that the extent of the orange pattern is a quantitative trait resulting from many loci of minor effect, we used a maximum likelihood model-fitting framework to show that it is better explained as a simple Mendelian trait, with the solid yellow morph being dominant over the blush orange. The relatively simple genetic architecture underlying this important trait helps explain the complex distribution of dewlap color variation across the range of A. distichus and suggests that changes in dewlap color and pattern may evolve rapidly in response to natural selection. [ABSTRACT FROM AUTHOR]

Ectotherms that maintain thermal balance in the face of varying climates should be able to colonise a wide range of habitats. In lizards, thermoregulation usually appears as a variety of behaviours that buffer external influences over physiology. Basking species rely on solar radiation to raise body temperatures and usually show high thermoregulatory precision. By contrast, species that do not bask are often constrained by climatic conditions in their habitats, thus having lower thermoregulatory precision. While much focus has been given to the effects of mean habitat temperatures, relatively less is known about how seasonality affects the thermal biology of lizards on a macroecological scale. Considering the current climate crisis, assessing how lizards cope with temporal variations in environmental temperature is essential to understand better how these organisms will fare under climate change. Activity body temperatures (Tb) represent the internal temperature of an animal measured in nature during its active period (i.e. realised thermal niche), and preferred body temperatures (Tpref) are those selected by an animal in a laboratory thermal gradient that lacks thermoregulatory costs (i.e. fundamental thermal niche). Both traits form the bulk of thermal ecology research and are often studied in the context of seasonality. In this study, we used a meta‐analysis to test how environmental temperature seasonality influences the seasonal variation in the Tb and Tpref of lizards that differ in thermoregulatory strategy (basking versus non‐basking). Based on 333 effect sizes from 137 species, we found that Tb varied over a greater magnitude than Tpref across seasons. Variations in Tb were not influenced by environmental temperature seasonality; however, body size and thermoregulatory strategy mediated Tb responses. Specifically, larger species were subjected to greater seasonal variations in Tb, and basking species endured greater seasonal variations in Tb compared to non‐basking species. On the other hand, the seasonal variation in Tpref increased with environmental temperature seasonality regardless of body size. Thermoregulatory strategy also influenced Tpref, suggesting that behaviour has an important role in mediating Tpref responses to seasonal variations in the thermal landscape. After controlling for phylogenetic effects, we showed that Tb and Tpref varied significantly across lizard families. Taken together, our results support the notion that the relationship between thermal biology responses and climatic parameters can be taxon and trait dependent. Our results also showcase the importance of considering ecological and behavioural aspects in macroecological studies. We further highlight current systematic, geographical, and knowledge gaps in thermal ecology research. Our work should benefit those who aim to understand more fully how seasonality shapes thermal biology in lizards, ultimately contributing to the goal of elucidating the evolution of temperature‐sensitive traits in ectotherms. [ABSTRACT FROM AUTHOR]

Motivation: I present a database that contains information on multiple key traits for all 11,744 recognised species of squamates worldwide. The database encompasses key traits and a reasonably comprehensive picture of available public knowledge. I present comprehensive description of the sources and rationale leading to the assignment of each particular trait state for each species. I hope the dataset can serve the scientific community, promote research and understanding of the group, comparisons with other taxa, and assessment of conservation needs. Furthermore, gaps in our knowledge of squamate traits become readily apparent and will hopefully lead to further study and even better knowledge. Main types of variables contained: Morphological, ecological, life history, geographical and conservation‐related traits. Spatial location: Global. Time period: Late Holocene to recent. Major taxa and level of measurement: Squamata, species. Software format: xlsx. [ABSTRACT FROM AUTHOR]

Colour is an important visual cue that can correlate with sex, behaviour, life history or ecological strategies, and has evolved divergently and convergently across animal lineages. Its genetic basis in non‐model organisms is rarely known, but such information is vital for determining the drivers and mechanisms of colour evolution. Leveraging genetic admixture in a rare contact zone between oviparous and viviparous common lizards (Zootoca vivipara), we show that females (N = 558) of the two otherwise morphologically indistinguishable reproductive modes differ in their ventral colouration (from pale to vibrant yellow) and intensity of melanic patterning. We find no association between female colouration and reproductive investment, and no evidence for selection on colour. Using a combination of genetic mapping and transcriptomic evidence, we identified two candidate genes associated with ventral colour differentiation, DGAT2 and PMEL. These are genes known to be involved in carotenoid metabolism and melanin synthesis respectively. Ventral melanic spots were associated with two genomic regions, including a SNP close to protein tyrosine phosphatase (PTP) genes. Using genome re‐sequencing data, our results show that fixed coding mutations in the candidate genes cannot account for differences in colouration. Taken together, our findings show that the evolution of ventral colouration and its associations across common lizard lineages is variable. A potential genetic mechanism explaining the flexibility of ventral colouration may be that colouration in common lizards, but also across squamates, is predominantly driven by regulatory genetic variation. [ABSTRACT FROM AUTHOR]

Studies on the gut microbiome of free-living reptiles in Europe are generally fragmentary and still missing in Bulgaria. We aimed to identify and compare the fecal microbiota profiles of five syntopic lizard species from three families: the European green lizard (Lacerta viridis), the common wall lizard (Podarcis muralis), the meadow lizard (Darevskia praticola) (Lacertidae), the European snake-eyed skink (Ablepharus kitaibelii) (Scincidae), and the European slow worm (Anguis fragilis) (Anguidae), which coinhabit a low mountainous area in the western part of the country. A high-throughput sequencing of the hypervariable V3-V4 region of the 16S rRNA gene, performed on the Illumina HiSeq2500 platform, was used. The core microbiota of lizard hosts seems to be species-specific. A dynamic phyla proportion between hosts was found. The richest alpha diversity was observed in D. praticola, and the lowest alpha diversity was observed in P. muralis and A. fragilis. Within the three lacertids, the microbiota of D. praticola and L. viridis were more closely related to each other than they were to those of P. muralis. Sharing a largely common trophic resource (all species except A. fragilis are mainly insectivorous) was not an indication of similarity in their gut microbial communities. [ABSTRACT FROM AUTHOR]

Understanding the genetic basis for adapting to thermal environments is important due to serious effects of global warming on ectothermic species. Various genes associated with thermal adaptation in lizards have been identified mainly focusing on changes in gene expression or the detection of positively selected genes using coding regions. Only a few comprehensive genome‐wide analyses have included noncoding regions. This study aimed to identify evolutionarily conserved and accelerated genomic regions using whole genomes of eight Anolis lizard species that have repeatedly adapted to similar thermal environments in multiple lineages. Evolutionarily conserved genomic regions were extracted as regions with overall sequence conservation (regions with fewer base substitutions) across all lineages compared with the neutral model. Genomic regions that underwent accelerated evolution in the lineage of interest were identified as those with more base substitutions in the target branch than in the entire background branch. Conserved elements across all branches were relatively abundant in "intergenic" genomic regions among noncoding regions. Accelerated regions (ARs) of each lineage contained a significantly greater proportion of noncoding RNA genes than the entire multiple alignment. Common genes containing ARs within 5 kb of their vicinity in lineages with similar thermal habitats were identified. Many genes associated with circadian rhythms and behavior were found in hot‐open and cool‐shaded habitat lineages. These genes might play a role in contributing to thermal adaptation and assist future studies examining the function of genes involved in thermal adaptation via genome editing. [ABSTRACT FROM AUTHOR]

So far, the phonation among worm lizards (Amphisbaenia) was virtually unknown, but herein we present for the first time a loud and clear record of sound emission by an amphisbaenian and its acoustic parameters. We observed an adult female of Amphisbaena alba emitting a high‐pitched sound, able to be heard a few meters away by a human ear. The sound was emitted with the mouth wide open and consisted of a short well‐defined note, presenting harmonics and frequency modulation. Based on the context of display and the body posture of the individual, we suggest that the oral emission of A. alba may be considered a defensive sound emission. However, based on the spectral structure of emission within hearing acuity reported for the species, we cannot disregard the possibility that this sound might act in communication with conspecifics. Beyond raising possible defensive and intra‐specific communication roles for the sound emissions of worm lizards, our findings contribute to the understanding of acoustic communication in tetrapods through the analysis of sounds produced by these fossorial reptiles. [ABSTRACT FROM AUTHOR]

Understanding the processes that shape genetic diversity by either promoting or preventing population divergence can help identify geographic areas that either facilitate or limit gene flow. Furthermore, broadly distributed species allow us to understand how biogeographic and ecogeographic transitions affect gene flow. We investigated these processes using genomic data in the Northern Alligator Lizard (Elgaria coerulea), which is widely distributed in Western North America across diverse ecoregions (California Floristic Province and Pacific Northwest) and mountain ranges (Sierra Nevada, Coastal Ranges, and Cascades). We collected single-nucleotide polymorphism data from 120 samples of E. coerulea. Biogeographic analyses of squamate reptiles with similar distributions have identified several shared diversification patterns that provide testable predictions for E. coerulea , including deep genetic divisions in the Sierra Nevada, demographic stability of southern populations, and recent post-Pleistocene expansion into the Pacific Northwest. We use genomic data to test these predictions by estimating the structure, connectivity, and phylogenetic history of populations. At least 10 distinct populations are supported, with mixed-ancestry individuals situated at most population boundaries. A species tree analysis provides strong support for the early divergence of populations in the Sierra Nevada Mountains and recent diversification into the Pacific Northwest. Admixture and migration analyses detect gene flow among populations in the Lower Cascades and Northern California, and a spatial analysis of gene flow identified significant barriers to gene flow across both the Sierra Nevada and Coast Ranges. The distribution of genetic diversity in E. coerulea is uneven, patchy, and interconnected at population boundaries. The biogeographic patterns seen in E. coerulea are consistent with predictions from co-distributed species. [ABSTRACT FROM AUTHOR]

Uncertainties on species taxonomy and distribution are major factors hampering efficient conservation planning in the current context of biodiversity erosion, even concerning widespread and abundant species in relatively well‐studied regions. Species delimitation have long been based on phylogenetic analyses of a small number of standard markers, but accurate lineage identification through this approach can be hampered by incomplete lineage sorting, introgression or isolation by distance. In that context, analyses of introgression patterns at secondary contact zones offer an interesting alternative by allowing a direct estimation of reproductive isolation, especially when using genome‐wide markers. Here, we investigated a contact zone between two genetic groups of the Spiny‐footed Lizard Acanthodactylus erythrurus (Schinz, 1833) in Morocco, whose status as separate lineages remained disputed in previous multilocus studies. Based on thousands of genome‐wide markers obtained through a RADseq approach, we confirmed that they represent distinct evolutionary lineages. Furthermore, the transition at their contact zone was very steep, with spatially restricted gene flow, highlighting levels of reproductive isolation consistent with species‐level lineages. Our study further illustrates the power of RADseq‐based studies of contact zones to understand cryptic diversity in non‐model organisms. [ABSTRACT FROM AUTHOR]

Aim: Contemporary environmental, historical and evolutionary factors are increasingly used to decipher the drivers of spatial patterns of species richness. Evidence of such correlations for Chinese reptiles is scarce and poorly understood. We therefore explored the validity of the environmental capacity, historical climatic stability and diversification rates hypotheses on Chinese lizard richness. Location: Mainland China. Taxon: Squamata: Sauria. Methods: We mapped the distribution ranges of all 237 lizards in mainland China using a combination of different datasets. We used current environmental conditions (ambient energy, environmental productivity, and habitat heterogeneity), historical climate stability indices (long term: since ~3.3 Ma and short term: since the last glacial maximum) and mean tip diversification rates, to test whether current environmental conditions, historical climate change and diversification rates drive contemporary richness patterns of lizards in China. We applied piecewise structural equation models (pSEM) to jointly evaluate our hypotheses, considering direct and indirect effects. Results: Chinese lizards showed strong latitudinal diversity gradients. We found consistent support for contemporary climatic and environmental factors relationships with richness. Richness was also positively correlated with short‐term climatic stability, but less so with long‐term stability. Diversification rates were seldom found to be positively correlated with lizard richness. Main Conclusions: Our results support the environmental capacity and historical climate hypotheses, which link high richness to highly productive warm and stable regions (and low richness to cold and unstable regions). We conclude that post‐speciation dispersal and short‐term climatic oscillations quickly swamp the long‐term signal of diversification rates and climatic fluctuations, creating strong current climate–richness associations. [ABSTRACT FROM AUTHOR]

The age, growth, and fertility of two populations of Ablepharus bivittatus in the Talysh Mountains are presented. Altogether, 59 individuals were studied from two localities in the Ardabil Province, Iran, one being the village of Khanegah-e-Oliya in Namin region and the other the village of Majara in Khalkhal region. The age of the lizards was determined using skeletochronology. The average age in females was 3.6 ± 1.15 years (maximum of six years), in males 2.6 ± 1.24 (maximum of five years). The sections of tubular bones of many individuals were noted to have lines of arrested growth corresponding to hibernation and aestivation. Lizards grow intensely during the first three years of life, but then their growth slows down. Animals in the age groups of three years and older do not differ in body length. The age of pregnant lizards is 2–5 years, on average, 3.7 ± 0.91 years. The fertility of females does not depend on age. [ABSTRACT FROM AUTHOR]

The Persian lizard, or Brandt's lizard (Iranolacerta brandtii), is a narrowly distributed and poorly studied species. Information concerning the reproduction of these lizards in nature is based only on the results of autopsies of animals. New data are presented on the reproductive biology of I. brandtii obtained in laboratory conditions. Six adult lizards (three males and three females) were kept in a group in a terrarium. Females laid eggs from March 11 to January 15. During this period, females brought one (one female), two (one female), or three (one female) egg clutches, but not more than two clutches per calendar year. One clutch contained from two to four eggs. The mass of the entire egg clutch amounted to 18.0–45.6% of the female's body weight. The eggs were 14.6–17.3 mm long, 8.1–10.0 mm wide, and weighed 0.59–0.81 g. Incubation of eggs at 27–29°C lasted 67–89 days. Newborn lizards had a body length of 35.2–30.8 mm, a tail length of 55.1–61.8 mm, and a weight of 0.98–1.10 g. Small adult females of I. brandtii were noted to have relatively very large eggs and newborn juveniles, like green lizards from the genus Lacerta. At the same time, the fertility of this species is low, as in some rock lizards from the genus Darevskia. [ABSTRACT FROM AUTHOR]

Urosaurus nigricaudus is a phrynosomatid lizard endemic to the Baja California Peninsula in Mexico. This work presents a chromosome-level genome assembly and annotation from a male individual. We used PacBio long reads and HiRise scaffolding to generate a high-quality genomic assembly of 1.87 Gb distributed in 327 scaffolds, with an N50 of 279 Mb and an L50 of 3. Approximately 98.4% of the genome is contained in 14 scaffolds, with 6 large scaffolds (334–127 Mb) representing macrochromosomes and 8 small scaffolds (63–22 Mb) representing microchromosomes. Using standard gene modeling and transcriptomic data, we predicted 17,902 protein-coding genes on the genome. The repeat content is characterized by a large proportion of long interspersed nuclear elements that are relatively old. Synteny analysis revealed some microchromosomes with high repeat content are more prone to rearrangements but that both macro- and microchromosomes are well conserved across reptiles. We identified scaffold 14 as the X chromosome. This microchromosome presents perfect dosage compensation where the single X of males has the same expression levels as two X chromosomes in females. Finally, we estimated the effective population size for U. nigricaudus was extremely low, which may reflect a reduction in polymorphism related to it becoming a peninsular endemic. [ABSTRACT FROM AUTHOR]

In July 2021 we identified a new distribution locality of the lizard species Darevskia praticola in the region of the Poiana Ruscă Mountains in western Romania. The meadow lizard was identified west of Zolt village, on the side of the road to Luncanii de Sus, in a heavily forested area. The new record completes the known distribution range of D. praticola in the northern region of the Poiana Ruscă Mountains. Also, it represents the first connection between the populations from the western areas of the Poiana Ruscă Mountains and the ones from their eastern areas, which previously seemed isolated. [ABSTRACT FROM AUTHOR]

The article "Remembering Edwin Nicholas Arnold (1940 - 2023)" in the magazine Eidechse reports on the death of Dr. Edwin Nicholas Arnold, a renowned herpetological expert. Arnold was born on October 16, 1940, in Kidderminster, Worcestershire, and was the director of a significant herpetological center. He completed his scientific education at the University of Oxford and primarily worked on issues related to the functional anatomy of lizards. Arnold was also known for his work on the reptile fauna of the Middle East and the subfossil reptile fauna of the islands in the western Indian Ocean. He published several books, including a field guide to the amphibians and reptiles of Europe. Arnold will be remembered as one of the greatest herpetologists of his time and as a reserved gentleman with great scientific depth. [Extracted from the article]

The phenomenon of the formation of more than one tail in lizards and its causes are addressed. The lizard with the maximum number of degenerate tails at present is pointed out. In the following, a male Podarcis pityusensis pityusensis with two tails is reported. Finally, the lack of regenerative capacity in very old lizards is proven on the basis of own experience. [ABSTRACT FROM AUTHOR]

Aim: Species richness varies widely across space and is determined by underlying factors that drive species coexistence. Such factors include the speciation process (sympatric vs. allopatric), time since divergence, geographic context and intrinsic properties of the organisms. We model for the first time the coexistence dynamics of lizards and snakes across broad temporal and spatial scales, investigating whether an increase in niche divergence, dispersal abilities and inhabiting islands or continents affect their probability of coexistence. Location: Global. Time period: Cenozoic. Major taxa studied: Squamata. Methods: We used 447 sister species pairs, their age since divergence, their level of spatial (sympatric or allopatric) and niche overlap and geographical setting (islands or continents) to fit probabilistic models of species coexistence. We measured morphological traits to quantify niche divergence and used range and body size as proxies for dispersal ability. We applied a model‐comparison framework in lizards and snakes separately to evaluate which factors best explained their coexistence dynamics. Results: Allopatric speciation is the main speciation mode in snakes but we did not find evidence to favour one speciation mode in lizards. In snakes, sympatric pairs tend to occur on islands and to be more different in body size. On the contrary, dispersal ability shaped the coexistence of lizards, where species were more likely to coexist when they have higher dispersal abilities. Main conclusions: Distinct patterns and mechanisms underlie species coexistence within the order Squamata. Snake coexistence is preferentially produced by secondary sympatry favoured by niche divergence and is more likely to occur in more restricted geographical settings (islands vs. continents). Coexistence in lizards is strongly influenced only by dispersal abilities, but the high heterogeneity of processes simultaneously shaping the distribution of different lizard lineages might have masked specific coexistence signals, and future work should compare coexistence dynamics between clades (e.g. families). [ABSTRACT FROM AUTHOR]

Locating potential mates in non-native habitats is one of the most important challenges faced by invasive vertebrate species. The Argentine black and white tegu lizard (Salvator merianae) is a major invasive reptile species in the contiguous United States and is rapidly expanding its range across Florida and the Southeast, in part due to inadequate management strategies and tools. Because a wide array of reptiles, especially squamates (snakes and lizards), have been well-studied for their reliance on chemical cues to locate conspecifics, our project aimed to isolate chemical cues from tegus and assess the ability of adult males and females to use only these cues to make navigation decisions within a Y-maze. Previously, we found that both males and females can follow conspecific scent trails, but the nature of the specific cues used by the tegus was unknown. In this study, we extracted skin lipids from male and female shed skins acquired during the breeding season then tested the extracts for bioactivity at different dilutions prior to Y-maze trials. Both sexes showed positive reactions (e.g., tongue-flicking, nose taps, scratching) to 2:1 skin lipid:hexane dilutions. In the Y-maze, males (n = 7) and females (n = 7) were run in three types of trailing scenarios with these skin lipid extracts: Male-only (pooled lipid extracts from male shed skins), Female-only (extracts from female shed skins), and Male vs. female. Regardless of the tegu lipid type present, tegus preferred to follow the conspecific lipid trail when paired with a neutral control (peanut oil; 2:1 dilution). They also preferred opposite-sex skin lipid trails when paired with same-sex skin lipid trails. We analyzed our results further by comparing them to those of Richard, Bukovich, et al. (2020). We found a synchronization effect of the skin lipids: sex differences in behavior detectable in the scent trail trials were absent when only conspecific skin lipids were present in the environment. Our results indicate that skin lipids alone are sufficient to facilitate mate tracking in S. merianae, these chemical cues induce reliable behavior, and extracted skin lipids have potential for modifying movement patterns of an invasive reptile in their non-native range. If leveraged in concert with current tegu management strategies (i.e., trapping), extracted skin lipids have the potential to bolster management efficacy but field trials are a requisite next step. [ABSTRACT FROM AUTHOR]

An organism's gut microbiota can change in response to novel environmental conditions, in particular when colonisation of new habitats is accompanied by shifts in the host species' ecology. Here, we investigated the gut microbiota of three lizard species (A. inornata, H. maculata and S. cowlesi) from their ancestral‐like habitat in the Chihuahuan desert and two colonised habitats with contrasting geological and ecological compositions: the White Sands and Carrizozo lava flow. The host species and the lizards' environment both shape gut microbiota composition, but host effects were overall stronger. Further, we found evidence that colonisation of the same environment by independent host species led to parallel changes of the gut microbiota, whereas the colonisation of two distinct environments by the same host species led to gut microbiota divergence. Some of the gut microbiota changes that accompanied the colonisation of the White Sands were associated with shifts in diet (based on diet information from previous studies), which is congruent with the general observation that trophic ecology has a strong effect on gut microbiota composition. Our study provides insights into how shifts in host ecology accompanying colonisation of novel environments can affect gut microbiota composition and diversity. [ABSTRACT FROM AUTHOR]

The Himalayan foothills and associated environment are well‐known for driving the rapid diversification of many species and the formation of biodiversity hotspots. The effects of environmental change since the Miocene have accelerated species diversification, and hence are useful for studying population genetic structure, and evolutionary relationships via genetic approaches. To date, the effects of climatic fluctuations on the biogeography of large‐bodied lizards have not been assessed comprehensively. Herein, we examine the diversification of Varanus bengalensis, focusing on its genetic structure to provide insights into how landscape structure and climatic fluctuations have shaped species differentiation. We confirm the existence of two distinct lineages within V. bengalensis distributed across the Himalayan foothills and the remainder of mainland India. Divergence analyses revealed the split between the Himalayan foothills and the remainder of the mainland lineages of V. bengalensis in the mid‐Pliocene ~3.06 Ma, potentially as a consequence of the Siwalik broadening and climatic fluctuations across the Himalayan foothills. The results suggest recognition of a new lineage of V. bengalensis from the Himalayan foothills as a distinctive evolutionarily significant unit. [ABSTRACT FROM AUTHOR]

A complete and high-quality reference genome has become a fundamental tool for the study of functional, comparative, and evolutionary genomics. However, efforts to produce high-quality genomes for African taxa are lagging given the limited access to sufficient resources and technologies. The southern African dwarf chameleons (Bradypodion) are a relatively young lineage, with a large body of evidence demonstrating the highly adaptive capacity of these lizards. Bradypodion are known for their habitat specialization, with evidence of convergent phenotypes across the phylogeny. However, the underlying genetic architecture of these phenotypes remains unknown for Bradypodion , and without adequate genomic resources, many evolutionary questions cannot be answered. We present de novo assembled whole genomes for Bradypodion pumilum and Bradypodion ventrale , using Pacific Biosciences long-read sequencing data. BUSCO analysis revealed that 96.36% of single copy orthologs were present in the B. pumilum genome and 94% in B. ventrale. Moreover, these genomes boast scaffold N50 of 389.6 and 374.9 Mb, respectively. Based on a whole genome alignment of both Bradypodion genomes, B. pumilum is highly syntenic with B. ventrale. Furthermore, Bradypodion is also syntenic with Anolis lizards, despite the divergence between these lineages estimated to be nearly 170 Ma. Coalescent analysis of the genomic data also suggests that historical changes in effective population size for these species correspond to notable shifts in the southern African environment. These high-quality Bradypodion genome assemblies will support future research on the evolutionary history, diversification, and genetic underpinnings of adaptation in Bradypodion. [ABSTRACT FROM AUTHOR]

Despite the nearly ubiquitous nature of sleep in the animal kingdom, behavioural research on sleep has focused on a few model organisms and widespread behaviours studied in artificial laboratory settings. In this study, we examine the ontogeny of sleeping perch selection in four closely related species of arboreal lizard in situ. The study species each occupy similar habitats and share 'solitary' ecology wherein potential lizard competitors are absent, thus providing four partially independent replicates with which to test hypotheses. We find that structural niche, analysed as perch height, varies by age and sex. Males sleep higher than females and adults sleep higher than juveniles in three of four species. Adults exhibit greater variability in sleep site selection. These patterns may reflect diurnal behaviour or indicate selective differences in sleeping perch variability across sex and ontogeny. [ABSTRACT FROM AUTHOR]

Urban environments offer dramatically different habitats for wildlife compared with natural environments. They provide, for example, different levels of resource availability, anthropogenic night light, and microclimates (e.g., urban heat islands). For reptiles, increased temperatures in the city can lead to increased energetic demands and metabolic rates unless they change their morphology and physiology and adapt or acclimatize to the urban conditions. We explored differences in metabolic rate, evaporative water loss, and body size of two lizard species – rock agamas (Laudakia vulgaris) and Mediterranean house geckos (Hemidactylus turcicus), from urban habitats and nearby natural open areas. When tested in the lab, we expected to identify physiological adaptations resulting in decreased metabolism in urban individuals. Both species had similar body lengths and masses at both habitat types, suggesting any differences in costs and benefits between urban and natural environments do not affect their overall size or body condition. In the laboratory, metabolic rates were similar in individuals from both habitats for both species, indicating no long‐term adaptations in this trait. However, urban geckos (but not agamas) had higher evaporative water loss than conspecifics from more natural habitats. This may suggest different compositions of epidermal lipids affecting the gecko skin's resistance to evaporation between the habitats. Overall, our results highlight different elements of the urban environment that might affect reptiles. However, the differences between species urge caution in interpreting the results to other species and locations. With increasing urbanization worldwide, understanding when and to what degree local adaptations can occur can help us predict reptile species distribution and survival in light of future anthropogenic changes. [ABSTRACT FROM AUTHOR]

A fundamental goal of population genetic studies is to identify historical biogeographic patterns and understand the processes that generate them. However, localized demographic events can skew population genetic inference. Assessing populations with multiple types of genetic markers, each with unique mutation rates and responses to changes in population size, can help to identify potentially confounding population‐specific demographic processes. Here, we compared population structure and connectivity inferred from microsatellites and restriction site‐associated DNA loci among 17 populations of an arid‐specialist lizard, the desert night lizard, Xantusia vigilis, in central California to test among historical processes structuring population genetic diversity. We found that both marker types yielded generally concordant insights into population genetic structure including a major phylogenetic break maintained between two populations separated by less than 10 km, suggesting that either marker type could be used to understand generalized demographic patterns across the region for management purposes. However, we also found that the effects of demography on marker discordance could be used to elucidate population histories and distinguish among competing biogeographic hypotheses. Our results suggest that comparisons of within‐population diversity across marker types provide powerful opportunities for leveraging marker discordance, particularly for understanding the creation and maintenance of contact zones among clades. [ABSTRACT FROM AUTHOR]

What factors render a species more vulnerable to extinction? In reptiles, foraging mode is a fundamental ecological dimension: some species actively search for immobile prey, whereas others ambush mobile prey. Foraging mode is linked to diet, morphology, movement ecology, and reproductive output, and hence plausibly might affect vulnerability to threatening processes. Our analyses of data on 1543 taxa revealed links between foraging mode and (IUCN) conservation status, but in opposite directions in the two main squamate groups. Ambush‐foraging snakes were more threatened and with declining populations than were active searchers, whereas lizards showed the reverse pattern. This divergence may be linked to differing consequences of foraging mode for feeding rates and reproductive frequency in snakes versus lizards. Our findings underscore the need for taxon‐specific conservation management, particularly in groups such as reptiles that have been neglected in global conservation prioritization. [ABSTRACT FROM AUTHOR]

Biotremors are vibrations, usually surface waves along the boundary of a medium, produced by an organism. While substrate-borne vibrations are utilized by different reptile species, true conspecific communication via biotremors has not yet been demonstrated in lizards. Recent research revealed that the veiled chameleon (Chamaeleo calyptratus) produces biotremors. The prerequisites for any communication system are the ability of an organism to produce and detect a signal. We tested C. calyptratus behavioral responses to vibrations by placing them on a dowel attached to a shaker, emitting vibrations of 25, 50, 150, 300, and 600 Hz and compared their locomotory velocity before and after the stimulus. Adult chameleons exhibited a freeze response to 50 and 150 Hz, while juveniles exhibited a similar response to frequencies between 50 and 300 Hz. In a second experiment, chameleons were induced to produce biotremors via experimenter contact. These biotremors ranged in mean fundamental frequency from 106.4 to 170.3 Hz and in duration from 0.06 to 0.29 s. Overall, two classes of biotremors were identified, "hoots" and "mini-hoots," which differed significantly in mean relative signal intensity (−7.5 and −32.5 dB, respectively). Juvenile chameleons 2 months of age were able to produce biotremors, suggesting this behavior may serve a wide range of ecological functions throughout ontogeny. Overall, the data demonstrate that C. calyptratus can both produce and detect biotremors that could be used for intraspecific communication. [ABSTRACT FROM AUTHOR]

We here describe two isolated fossil teeth from the Early Miocene (MN 4) of Hüenerbach, Switzerland. The material is tentatively referred to Varanus, marking the first occurrence of this iconic lizard genus in the Swiss fossil record, while it also represents one of its earliest occurrences from Europe, being coeval with other records from Spain, France, and the Czech Republic. Important diagnostic features in the teeth of extant Varanus are discussed, coupled with comparisons with related taxa. The prominent serration in one of the two Swiss teeth is an unusual feature for European varanids. In addition, the sole other lizard specimen from Hüenerbach is also described, being referred to an indeterminate lacertid, with potential affinities to the genus Janosikia. [ABSTRACT FROM AUTHOR]

Thirteen adult healthy captive skinks, six Gidgee spiny-tailed skinks (Egernia stokesii), three Hosmer's spiny-tailed skinks (Egernia hosmeri) and four tree crevice-skinks (Egernia striolata), were submitted to the study. The weight of the animals ranged from 28 g to 146 g. All skinks were explored during their putative mating season, which is December. Lizards were restrained manually and positioned in ventral recumbence. Cloacoscopy was performed with the rigid endoscope, protecting channel, endocamera and recording system Telepack-Pal (Karl Storz Endoskope, Tuttlingen, Germany). While the endoscope was gently introduced into the cloaca and advanced into the coprodeum sterile saline was flushed into the cloaca through the protecting channel. The endoscope was then slowly withdrawn to allow visualization of the main structures of the urodeum and proctodeum. Male skinks are characterized by the presence of urethral papillae and only one horizontal septum which divides the chamber of the urodeum into two subchambers. Female skinks are characterised by the presence of two septa. The centraldorsal fold that divides the urodeum into two pouches in female skinks is absent in males. Cloacoscopy proved an effective method of sex identification and can be considered a valuable method for breeding and conservation in monomorphic skink lizards. [ABSTRACT FROM AUTHOR]

Simple Summary: Digital radiography has long been established in veterinary clinics, leading to increased use of digital systems in reptile species as well. In this study, we used different digital radiography systems on cadavers of bearded dragons (Pogona vitticeps). We aimed to examine the impact of a radiation dose reduction on the image quality and the assessment of defined skeletal structures. We employed a blinded assessment and a defined scoring system to evaluate the techniques tested. Our results demonstrate that both a 50% and a 75% reduction in the radiation dose significantly decreased image assessments. These findings highlight the need for correct radiation dose protocols to produce high-quality radiographs in reptile species. Three different digital detector systems were used to study the effect of a defined radiation dose reduction on the image quality of digital radiographs in bearded dragons (Pogona vitticeps). A series of radiographs of seven bearded-dragon cadavers with a body mass ranging from 132 g to 499 g were taken in dorsoventral projection. The digital systems employed included two computed radiography systems (CR) (one system with a needle-based and one with a powdered-based scintillator) and one direct radiography system (DR). Three levels of the detector dose were selected: A standard dose (defined based on the recommended exposure value of the CRP, D/100%), a half dose (D/50%), and a quarter dose (D/25%). Four image criteria and one overall assessment were defined for each of four anatomic skeletal regions (femur, rib, vertebra, and phalanx) and evaluated blinded by four veterinarians using a predefined scoring system. The results were assessed for differences between reviewers (interobserver variability), radiography systems, and dosage settings (intersystem variability). The comparison of the ratings was based on visual grading characteristic (VGC) analysis. Dose reduction led to significantly lower scores in all criteria by every reviewer, indicating a linear impairment of image quality in different skeletal structures in bearded dragons. Scores did not differ significantly between the different systems used, indicating no advantage in using a computed or direct radiography system to evaluate skeletal structures in bearded dragons. The correlation was significant (p ≤ 0.05) for interobserver variability in 100% of the cases, with correlation coefficients between 0.50 and 0.59. While demonstrating the efficacy of the use of digital radiography in bearded dragons and the similar quality in using different computed or direct radiography systems, this study also highlights the importance of the appropriate level of detector dose and demonstrates the limits of post-processing algorithm to compensate for insufficient radiation doses in bearded dragons. [ABSTRACT FROM AUTHOR]

Spatial patterns of body size are associated with environmental factors like temperature, seasonality, precipitation, resources, and altitude, among the most relevant. Latitudinal size patterns have been extensively studied. Studies on altitudinal gradients of body size, however, are relatively few. Besides, it is still unclear whether there is variation in the relationship between environmental factors and body size of species, or correlations within different altitudes. China provides a good opportunity to assess the altitudinal gradients of body size, because the entire terrain of China changes from high altitude in the west to low altitude in the east, with three natural terrain stages (low: less than 660 m.a.s.l.; medium: 660–2600 m.a.s.l.; and high: more than 2600 m.a.s.l.). Similarly, lizards are distributed across a wide altitudinal range (from −154.31 m to ~6000 m above sea level). We examined 211 lizard species in China and assessed the altitudinal gradients of Chinese lizard body sizes at assemblage and interspecific levels. Piecewise structural equation models (pSEM) were used to investigate the direct and indirect relationships between body size and environmental factors within different terrains (low, medium, and high altitudes). Overall, we found that body size in Chinese lizards decreases with increasing altitude. However, there were variations in the altitudinal gradients and drivers within the three terrain stages. Altitude has both direct (medium and low stages) and indirect (high stages) effects in shaping lizard size. We established that body size increased with increasing altitudes in the low and medium terrain stages. Seasonality had different effects on body size in medium (positively) and low (negatively) stages. However, among the three terrain stages, temperature was consistently negatively correlated with lizard size. Overall, we identified complex patterns and drivers of altitudinal gradients of body size within the three terrain stages, probably due to the different environmental conditions across altitudes. [ABSTRACT FROM AUTHOR]

The Wadi Rum Reserve in Jordan is home to at least 34 reptile species, including the endangered lizard species Phoenicolacerta kulzeri. During a four-day stay in the reserve, the author was able to identify ten lizard species, including Phoenicolacerta kulzeri khazaliensis, whose presence was observed for the first time outside its typical habitat. Further field studies should be conducted to obtain accurate data on the distribution of this lizard species. [Extracted from the article]

Residual yolk is assumed to be an important source of energy and nutrients during early life in nonmammalian amniotes. Available data show that the mean size of residual yolk is far smaller in lizards than in turtles, snakes, crocodiles, and birds, raising a question of whether residual yolk is of functional significance in lizards. Here, we compared data from 26 lizard species with those from other nonmammalian amniotes to test the hypothesis that residual yolk is functionally less significant in species producing more fully developed offspring. In our sample, species mean offspring water contents ranged from 73% to 84% of body wet mass; species mean proportions of carcass dry mass, fat-body dry mass, and residual yolk dry mass to offspring dry mass ranged from 84% to 99%, 0% to 5.0%, and 0% to 14.4%, respectively. Lizards are, on average, more fully developed at hatching or birth than snakes, as revealed by the fact that the mean proportion of carcass dry mass to body dry mass and offspring water contents were both higher in lizards than in snakes. We conclude that the functional significance of residual yolk during early life is generally less evident in lizards. Even in the lizards where residual yolk is of potential functional significance, this portion of yolk contributes little, if any, to postembryonic growth. Future work could usefully collect data across a wider spectrum of reptile taxa to establish a precocial–altricial continuum and test the hypothesis that species with a smaller amount of residual yolk are closer to the precocial end of the continuum. [ABSTRACT FROM AUTHOR]

Despite numerous works devoted to hybrid origin of parthenogenesis in reptiles, the causes of hybridization between different species, resulting in the origin of parthenogenetic forms, remain uncertain. Recent studies demonstrate that sexual species considered parental to parthenogenetic rock lizards (Darevskia spp.) avoid interspecific mating in the secondary overlap areas. A specific combination of environmental factors during last glaciation period was critical for ectotherms, which led to a change in their distribution and sex ratio. Biased population structure (e.g., male bias) and limited available distributional range favored the deviation of reproductive behavior when species switched to interspecific mates. To date, at least 7 diploid parthenogenetic species of rock lizards (Darevskia, Lacertidae) originated through interspecific hybridization in the past. The cytogenetic specifics of meiosis, in particular the weak checkpoints of prophase I, may have allowed the formation of hybrid karyotypes in rock lizards. Hybridization and polyploidization are 2 important evolutionary forces in the genus Darevskia. At present, throughout backcrossing between parthenogenetic and parental species, the triploid and tetraploid hybrid individuals appear annually, but no triploid species found among Darevskia spp. on current stage of evolution. The speciation by hybridization with the long-term stage of diploid parthenogenetic species, non-distorted meiosis, together with the high ecological plasticity of Caucasian rock lizards provide us with a new model for considering the pathways and persistence of the evolution of parthenogenesis in vertebrates. [ABSTRACT FROM AUTHOR]

[Display omitted] • We reassess the phylogenetic relationships and taxonomic status within the Adeleorina, a cosmopolitan order of parasites. • Karyolysus Labbé 1894 is the main blood parasite found in reptiles in the western Mediterranean and Macaronesia. • We found a lack of co-speciation signal between these parasites and their lizard hosts. • Host genera with diverging histories approximately 18 million years ago shared some parasite haplotypes. • A higher sampling effort is still needed worldwide in other large clades of Adeleorina. The genus Karyolysus was originally proposed to accommodate blood parasites of lacertid lizards in Western Europe. However, recent phylogenetic analyses suggested an inconclusive taxonomic position of these parasites of the order Adeleorina based on the available genetic information. Inconsistencies between molecular phylogeny, morphology, and/or life cycles can reflect lack of enough genetic information of the target group. We therefore surveyed 28 localities and collected blood samples from 828 lizards of 23 species including lacertids, skinks, and geckoes in the western Mediterranean, North Africa, and Macaronesia, where species of Karyolysus and other adeleorine parasites have been described. We combined molecular and microscopic methods to analyze the samples, including those from the host type species and the type locality of Karyolysus bicapsulatus. The phylogenetic relationship of these parasites was analyzed based on the 18S rRNA gene and the co-phylogenetic relationship with their vertebrate hosts was reconstructed. We molecularly detected adeleorine parasites in 37.9% of the blood samples and found 22 new parasite haplotypes. A phylogenetic reconstruction with 132 sequences indicated that 20 of the newly detected haplotypes clustered in a well-supported clade with another 18 sequences that included Karyolysus galloti and Karyolysus lacazei. Morphological evidence also supported that K. bicapsulatus clustered in this monophyletic clade. These results supported the taxonomic validity of the genus. In addition, we found some parasite haplotypes that infected different lizard host genera with ancient diverging histories, which suggested that Karyolysus is less host-specific than other blood parasites of lizards in the region. A co-phylogenetic analysis supported this interpretation because no significant co-speciation signal was shown between Karyolysus and lizard hosts. [ABSTRACT FROM AUTHOR]

Simple Summary: Various snake and lizard species have transparent and fused eyelids that make up a spectacle. From an evolutionary point of view, it is assumed that ancestral snakes developed this structure to protect the eye as an adaptation to their burrowing, underground existence. Between the spectacle and the eye lies a narrow subspectacular space that is filled with a tear-like fluid that drains to the roof of the mouth via the lacrimal duct. Although disorders of the eye are relatively uncommon in squamates with a spectacle, disorders of the spectacle, the subspectacular space, and its drainage system are frequently encountered in veterinary practice. As the spectacle is an integral part of the skin it is renewed with each shedding cycle. Retention of the old layers of the spectacle may occur because of infectious as well as non-infectious causes. Besides inflammation and trauma of the spectacle, overfilling due to blockage of the drainage system (pseudobuphthalmos) as well as bacterial and parasitic infection of the subspectacular space (subspectacular infection) are undoubtedly the most frequently observed disorders in snakes and spectacled lizards. An adequate diagnostic approach often allows the establishment of a successful treatment for these conditions. Various squamate species have completely fused eyelids that make up a transparent spectacle. The spectacle is a continuation of the integument that is renewed with each shedding cycle and creates a narrow subspectacular or corneospectacular space that is filled with lacrimal fluid. The latter is considered as the analogue of the conjunctival sac in other vertebrates. Almost all reptiles that have a spectacle lack a nictitating membrane, bursalis muscle, and lacrimal glands. The lacrimal fluid in the subspectacular space is secreted by the Harderian gland. The features of the spectacle and its lacrimal drainage system are an illustration of the enormous variation of the morphological adaptations that are seen in reptiles and one of the most distinguishable traits of snakes and most gecko species. Whereas ocular disease in squamates with a spectacle is infrequently seen in practice, disorders of the spectacle and the subspectacular space are commonly encountered. In order to apply an adequate diagnostic and therapeutic approach for these conditions, a sound knowledge and understanding of the anatomical and physiological peculiarities of the spectacle, subspectacular space, and lacrimal drainage system are fundamental. [ABSTRACT FROM AUTHOR]

Neophobia, the fear of novelty, is an ecologically important response which enables animals to avoid potentially harmful situations. Neophobia is a cognitive process by which individuals distinguish novelty from familiarity. In this study, we aimed to quantify this cognitive process in captive tokay geckos (Gekko gecko) across three contexts: when encountering novel prey, foraging near novel objects and entering a novel space. We also investigated individual consistency across trials using different novel stimuli, and correlation of individual responses across the three contexts. We found that geckos hesitate to attack novel prey and prey close to objects (familiar and novel). Geckos hesitated the most when entering novel space. Repeatability of behaviour within and across contexts was low (R = 0.101–0.190) indicating that neophobia might not be expressed similarly across contexts. The strength of a neophobic response can indicate how anxious or curious an individual is. This test has great potential to help answer questions about how captivity, enrichment, rearing environment and cognition affect fear responses in different contexts in lizards. By studying reptiles, we can better understand the universality of what is known about the causes leading to difference in neophobia across individuals and species. [ABSTRACT FROM AUTHOR]

We describe a new species of Proctoporus from the scientifically unexplored southern sector of the Otishi National Park (Region Cusco) in Peru, on the basis of molecular and morphological characters. Seven type specimens were obtained from six localities between 3241–3269 m a.s.l. within a radius of ca. 1.5 km in a Puna valley. Nine adult specimens (four males, five females) from Chiquintirca (Region Ayacucho, ca. 85 km airline from the type locality) are considered referred specimens. Males of the new species have a snout–vent length of 41.3–53.9 mm ( x ¯ = 46.7, n = 6), females have a snout–vent length of 43.6–52.6 mm ( x ¯ = 48.1, n = 8). The new species has dorsal scales striated, four supraoculars, four anterior supralabials, loreal and prefrontal scales absent, two pairs of genials (rarely one or three), three rows of pregulars, and five to seven femoral pores in males (absent in females). Sexual dimorphism is evident in the ventral coloration: males have neck, chest, and belly dark gray to black, whereas females have neck, chest, and belly pale gray with a diffuse dark gray fleck in the center of each scale, and an orange iris with a fringed pupil in both sexes. [ABSTRACT FROM AUTHOR]

The 16-year-old female leopard gecko (Eublepharis macularius) was presented with distended coelom and cachexia. Examination of the faecal sample ruled out the presence of protozoan parasites. A radiographic examination confirmed the presence of radiopaque foreign material in the intestine. The conservative treatment with tramadol, butylscopolamine, famotidine, vitamin B complex, and supportive fluid therapy with Hartmann solution and Duphalyte, was performed for 14 days. Ultrasonographic examination revealed the presence of a large mass adherent to the liver (with hypoechoic regions), a thin-walled cystic structure close to the liver, and coelomic effusion. Surgical exploration revealed a large mass on the right ovary. The unilateral (right) ovariectomy was performed. Histologic examination of the mass revealed dysgerminoma with an invasion of the ovarian bursa and blood vessels. Nine months after the surgery the patient was active and doing well. In reptiles, dysgerminoma is an uncommon type of neoplasia. To the best of our knowledge, this is the first case of dysgerminoma tumour diagnosed intravitally and treated successfully in lizards. [ABSTRACT FROM AUTHOR]

The systematic, phylogenetic, and biogeographic aspects of the rich squamate fauna of the Arabian Peninsula are becoming increasingly well understood. The Arabian members of the gecko genus Hemidactylus, the most diverse genus among Arabian squamates, have been the subject of several phylogenetic revisions in recent years. However, large parts of the peninsula lacked thorough sampling, for example, the coastal hyper-arid plains along the Red Sea and some offshore islands. In this study, we examine the genetic, morphological, and ecological diversification of a Hemidactylus clade that straddles the Red Sea and contains ten Arabian and three African species. We compiled a genetic dataset of seven markers (two mitochondrial and five nuclear) to reconstruct their phylogenetic relationships and collected morphological data to assess the level of interspecific morphological disparification. Our results support the existence of four yet undescribed species within the clade – two from Arabia and two from Ethiopia. We provide taxonomic descriptions of the two new Arabian species, one from the western Asir Mountains foothills and one from the Farasan Islands. The new species from the Asir Mountains foothills highlights the role of the southern Arabian coastal desert as an important yet often overlooked local biodiversity hotspot. The new species from the Farasan Islands represents the second vertebrate species endemic to the archipelago. Together with the descriptions of the diagnostic features of both species, we provide complete annotated mitochondrial genomes of both holotypes and of holotypes of two other species from the clade to characterize their mitogenomic composition and architecture. [ABSTRACT FROM AUTHOR]

DNA barcoding remains a recognized and widely used method for taxon identification in biodiversity inventory and monitoring. In this publication, we present information about the results of using this method in the study of green lizards of the genus Lacerta. A total of 67 sequences of the COI gene fragment of three species (L. agilis, L. media, and L. strigata) were analyzed. For the first time, all subspecies of L. agilis known in the Caucasus were studied using DNA barcoding, and a phylogeographic hypothesis for L. strigata in the Caucasian part of the range was proposed. Genetic identification has been successful at the species level. In the composition of L. agilis within the Caucasus, we can diagnose only the subspecies L. a. boemica and L. a. exigua, while L. a. brevicaudata, L. a. grusinica, and L. a. mzymtensis do not differ in this marker from L. a. exigua and L. a. ioriensis from L. a. boemica. [ABSTRACT FROM AUTHOR]

Pygopodids are more than forty species of gekkonoid lizards with an elongated body, no forelimbs and rudimentary hindlimbs that are reduced to flap appendices, endemic to Australasia. I explored the process of morphological evolution and diversification of pygopodids from a biogeographic and ecological perspective, subjecting body size and shape to comparative methods along a phylogenetic tree of species. In particular, I analysed the tempo of morphological diversification and disparification of Flap-footed Lizards in relation to the aridification of Australia and the arrival of Asian reptile faunae to the continent, and whether it is related to its ecological radiation and speciation. The transition from an ancestor with a short body and four limbs to the final elongated and partially limbless body plan of Pygopodidae occurred before the Miocene aridification of Australia. However, the current morphological diversification of Flap-footed Lizards is concordant with the opening of new habitats and the spread of the new squamate fauna that arrived from Asia during the Miocene aridification of Australia. Pygopodid lizards diversified in body shape and size from an ancestral terrestrial form with tail that was longer than the body, leading to different morphologies that do not fully agree with previous categorisations of the species’ ecologies. The evolution of body size in Flap-footed Lizards experienced an initial strong phenotypic rate that led to large disparity and was followed by a decline during the rest of its evolutionary history. Hence, the evolution of body size and the colonization of warm regions of Australia are positively associated with speciation whereas the diversity of body shapes could be linked with ecological divergences, thus suggesting that pygopodids deserve further investigation to test whether they must be considered an example of adaptive radiation. [ABSTRACT FROM AUTHOR]

Population isolation and concomitant genetic divergence, resulting in strong phylogeographical structure, is a core aspect of speciation initiation. If and how speciation then proceeds and ultimately completes depends on multiple factors that mediate reproductive isolation, including divergence in genomes, ecology and mating traits. Here we explored these multiple dimensions in two young (Plio‐Pleistocene) species complexes of gekkonid lizards (Heteronotia) from the Kimberley–Victoria River regions of tropical Australia. Using mitochondrial DNA screening and exon capture phylogenomics, we show that the rock‐restricted Heteronotia planiceps exhibits exceptional fine‐scale phylogeographical structure compared to the codistributed habitat generalist Heteronotia binoei. This indicates pervasive population isolation and persistence in the rock‐specialist, and thus a high rate of speciation initiation across this geographically complex region, with levels of genomic divergence spanning the "grey zone" of speciation. Proximal lineages of H. planiceps were often separated by different rock substrates, suggesting a potential role for ecological isolation; however, phylogenetic incongruence and historical introgression were inferred between one such pair. Ecomorphological divergence among lineages within both H. planiceps and H. binoei was limited, except that limestone‐restricted lineages of H. planiceps tended to be larger than rock‐generalists. By contrast, among‐lineage divergence in the chemical composition of epidermal pore secretions (putative mating trait) exceeded ecomorphology in both complexes, but with less trait overlap among lineages in H. planiceps. This system—particularly the rock‐specialist H. planiceps—highlights the role of multidimensional divergence during incipient speciation, with divergence in genomes, ecomorphology and chemical signals all at play at very fine spatial scales. [ABSTRACT FROM AUTHOR]

There is a lack of information for potential winter activity of the snake-eyed lizard Ophisops elegans in Europe, where it has a limited distribution. To test the hypothesis that this species can be active during the winter months, two locations in Bulgaria were chosen. The visits were conducted in January, February and December 2022 near the village of Meden Buk and in December 2022 above the village of Mezek. A total of 19 individuals of O. elegans were recorded. In addition, we confirmed foraging behaviour based on faecal sample collection. To our knowledge, this is the northernmost record of winter activity in the snake-eyed lizard and the first consecutive observation of year-round activity for this species in Europe. [ABSTRACT FROM AUTHOR]

Mesocestoides is a controversial tapeworm with significant lack of data related to systematics and life cycles. This helminth has an indirect life cycle with vertebrates, mostly carnivorous mammals, as definitive hosts. Theoretically, a coprophagous arthropod would be the first intermediate host, and herptiles, mammals, and birds, which prey on these insects, would represent the second intermediate hosts. However, recent evidence suggests that this life cycle would require only two hosts, with no arthropods involved. In the Neotropics, although there are records of mammals and reptiles as hosts for Mescocestoides , no molecular analyses have been performed. This work aimed to record an additional intermediate host and molecularly characterize the isolated larvae. Thus, 18 braided tree iguanas (Liolaemus platei) from Northern Chile were collected and dissected during 2019. One lizard was parasitized by three morphotypes of larvae compatible with tetrathyridia of Mescocestoides. To achieve its specific identity, a molecular approach was performed: 18S rRNA and 12S rRNA loci were amplified through cPCR. The inferred phylogenies confirmed the morphological diagnosis and stated that all morphotypes were conspecifics. The sequences for both loci formed a monophyletic clade with high nodal support, representing a sister taxon to Mescocestoides clade C. This study represents the first molecular characterization of any taxon of Mescocestoides from the Neotropics. Future surveys from potential definitive hosts would help to elucidate its life cycle. Furthermore, an integrative taxonomic approach is required in additional studies from the Neotropical region, which would contribute to a better understanding of the evolutionary relationships of this genus. [ABSTRACT FROM AUTHOR]

Headbobbing represents one of the primary sources of communication in Iguanian lizards. Here, we describe and analyze for the first time the form and structure of the headbob display in a species of the Phymaturus genus, and compare it across sexes, social contexts, and with other species of its family. We video-recorded Phymaturus palluma adult lizards, obtained the form and structure of headbobs and evaluated the effect of sex and social context on their performing generalized linear mixed models. We found that in P. palluma , headbob is a complex display composed of several units. Headbob pattern is stereotyped, with less than 35% of variation between individuals, suggesting that it is species-specific. Moreover, units vary among sex and social context, revealing that this display is multicomponent and non-redundant following the multiple-message hypothesis. We also found that the headbob pattern was more complex than in other Liolaemidae lizards, which probably is related to the social systems registered in Phymaturus. [ABSTRACT FROM AUTHOR]

Many lizard species face extinction due to worldwide climate change. The Guatemalan Beaded Lizard, Heloderma charlesbogerti, is a member of the Family Helodermatidae that may be particularly imperiled; fewer than 600 mature individuals are believed to persist in the wild. In addition, H. charlesbogerti lizards are phenotypically remarkable. They are large in size, charismatically patterned, and possess a venomous bite. Here, we report the draft genome of the Guatemalan Beaded Lizard using DNA from a wild-caught individual. The assembled genome totals 2.31Gb in length, similar in size to the genomes of related species. Single-copy orthologs were used to produce a novel molecular phylogeny, revealing that the Guatemalan Beaded Lizard falls into a clade with the Asian Glass Lizard (Anguidae) and in close association with the Komodo Dragon (Varanidae) and the Chinese Crocodile Lizard (Shinisauridae). In addition, we identified 31,411 protein-coding genes within the genome. Of the genes identified, we found 504 that evolved with a differential constraint on the branch leading to the Guatemalan Beaded Lizard. Lastly, we identified a decline in the effective population size of the Guatemalan Beaded Lizard approximately 400,000 years ago, followed by a stabilization before starting to dwindle again 60,000 years ago. The results presented here provide important information regarding a highly endangered, venomous reptile that can be used in future conservation, functional genetic, and phylogenetic analyses. [ABSTRACT FROM AUTHOR]

The genus Anatololacerta is distributed in the eastern Mediterranean region including Asia Minor and some east Aegean islands. Recent phylogenetic studies suggested that this genus displayed cryptic diversity and was divided into five species: A. anatolica, A. pelasgiana, A. ibrahimi, A. finikensis and A. danfordi. The ecological niche differentiations of these species have not been studied so far. Our aims for this study were to predict the potential suitable habitats for the species nested in genus Anatololacerta, and to examine the niche overlaps and differentiations via identity and background tests. The occurrence data were obtained from literature and our own field surveys. Occurrence records were rarefied and assessed in a 30 arc-second resolution layer, compatible with several bioclimatic and topographic variables. Species distribution analyses were performed using maximum entropy approach and pairwise niche comparisons were evaluated by identity and background tests. Our results demonstrated that the species delimitation among this genus was not only affected by geographic isolation but also that precipitation and temperature influenced the habitat suitability for these species. Predicted suitability usually well matched the actual species distributions. Moreover, the niche overlap (identity test) analyses verified that allopatric Anatololacerta species show clear ecological differentiations. However, a niche overlap between parapatric species A. pelasgiana and A. finikensis, was confirmed by identity and background tests. It has been suggested that these parapatric species could be more affected by microclimatological parameters than the others. The results of our study are in agreement with the latest phylogenetic study within this genus. [ABSTRACT FROM AUTHOR]