Genomics reveals broad hybridization in deeply divergent Palearctic grass and water snakes (Natrix spp.).

Understanding speciation is one of the cornerstones of biological diversity research. Currently, speciation is often understood as a continuous process of divergence that continues until genetic or other incompatibilities minimize or prevent interbreeding. The Palearctic snake genus Natrix is an ideal group to study speciation, as it comprises taxa representing distinct stages of the speciation process, ranging from widely interbreeding parapatric taxa through parapatric species with very limited gene flow in narrow hybrid zones to widely sympatric species. To understand the evolution of reproductive isolation through time, we have sequenced the genomes of all five species within this genus and two additional subspecies. We used both long-read and short-read methods to sequence and de-novo-assemble two high-quality genomes (Natrix h. helvetica, Natrix n. natrix) to their 1.7 Gb length with a contig N50 of 4.6 Mbp and 1.5 Mbp, respectively, and used these as references to assemble the remaining short-read-based genomes. Our phylogenomic analyses yielded a well-supported dated phylogeny and evidence for a surprisingly complex history of interspecific gene flow, including between widely sympatric species. Furthermore, evidence for gene flow was also found for currently allopatric species pairs. Genetic exchange among these well-defined, distinct, and several million-year-old reptile species emphasizes that speciation and maintenance of species distinctness can occur despite continued genetic exchange.

Revising the taxonomy of Darevskia valentini (Boettger, 1892) and Darevskia rudis (Bedriaga, 1886) (Squamata, Lacertidae): a Morpho-Phylogenetic integrated study in a complex Anatolian scenario.

Revealing biodiversity allows the accurate determination of the underlying causes of many biological processes such as speciation and hybridization. These processes contain many complex patterns, especially in areas with high species diversity. As two of the prominent zoogeographic areas, Anatolia and Caucasus are also home to the genus Darevskia, which has a complex morphological structure and parthenogenetic speciation. Darevskia valentini and D. rudis are two largely distributed taxa of this genus, both of which have a controversial taxonomic delimitation. Here we performed both a highly detailed morphological comparison and a molecular evaluation for the populations in both species groups. The most comprehensive taxonomic revision of this complex was carried out to determine the cases where the data obtained were compatible or not with each approach. As a result of the obtained outputs, it seems that D. spitzenbergerae stat. nov., D. mirabilis stat. nov. and D. obscura stat. nov. should be accepted as the species level, this later with subspecies D. o. bischoffi comb. nov. and D. o. macromaculata comb. nov.. Also, we propose two new taxa: D. josefschmidtleri sp. nov. and D. spitzenbergerae wernermayeri ssp. nov.. It has also been shown that "lantzicyreni" subspecies belong to D. rudis instead of D. valentini. The extensive revision has contributed to subsequent studies to more accurately understand the past histories of species in the genus Darevskia.

A case of allopatric speciation in the Central System (Iberian Peninsula): Leistus elpis sp. nov., a sibling species of Leistus constrictus (Coleoptera, Carabidae).

The aim of this work was to demonstrate that the Leistus (Leistus) constrictus Schaufuss 1862 populations from Sierra de Aylln belong to a new sibling species of the true L. (L.) constrictus from Sierra de Guadarrama. We describe Leistus (Leistus) elpis sp. nov. The species were separated by the study of external morphology of qualitative characters, especially male genitalia, and quantitative characters (morphometric analysis). In L. (L.) constrictus the apical lamina of the aedeagus appears to be a long gutter flanked by lateral ridges with an open truncation in its anterior part; in L. (L.) elpis sp. nov. the apical lamina is completely ridged, even in the anterior part, forming a kind of labial thickening, enclosing the median lobe, and giving the apex a clearly closed and pointed outline. It is not possible, or very difficult, to distinguish between females of L. (L.) constrictus and females of L. (L.) elpis sp. nov., based on their external anatomy as they are practically identical. The female genitalia do not offer taxonomic information for discriminating between the species using the genital armour or the structure of the spermathecal complex. However, subtle differences were found through morphometric analysis, as well as for males of both species. Field surveys suggest that the pass Puerto de Somosierra is the geographical barrier that has led to this allopatric speciation.

Multivariate analysis of geographic variation in Darevskia clarkorum (Darevsky amp; Vedmederja, 1977), correlation with geographic and climatic parameters, and true status of Darevskia dryada (Darevsky amp; Tuniyev, 1997).

All the Turkish populations studied, both those previously assigned to D. dryada (Subasi and Yoldere villages, near Hopa) and those attributed to D. clarkorum (the largest sample studied so far, 177 specimens in total), are indistinguishable from each other and therefore must all be ascribed to the natural variability of a monotypic D. clarkorum. The Georgian specimens from the Type Locality of D. dryada (Charnaly river gorge, Chevachauri district) are clearly different, so that taxon cannot be considered a simple synonym for D. clarkorum, but as a valid taxon, although its proper status (more probably as a subspecies of D. clarkorum), is yet to be clarified. It is a highly threatened population, so studies should be done in vivo or with as low intrusiveness as possible. Darevskia dryada is clearly larger (SVL) than any D. clarkorum studied, with strongly longer heads and pilei in adult males (and hence more teeth in dentary bone), and higher dorsalia counts. There also seem to be (but need to be studied in a larger sample) more longitudinal rows of temporal scales between tympanic and parietal plates, a tendency to have more supralabial scales; comparatively smaller values for longitudinal rows of scales on the ventral surface of the thigh between the femoral pores and the outer row of enlarged scales, and higher collaria, and circumanalia scales. Other differences in femoralia and gularia are also reflected in Darevsky Tuniyev's (1997) tables and should also be investigated with more Georgian specimens. Two supposed discriminant characters, the frontonasal index and the presence of developed masseteric, are not valid. The frontonasal index does not discriminate both taxa; D dryada specimens fall inside the variation of D. clarkorum for this character. Also the presence of a developed masseteric plate is supposed to be rare if at all in D. clarkorum but always present in D. dryada; however, it appears in nearly 75% of D. clarkorum studied and in all D. dyada, so is also no longer valid for taxa discrimination. Although very similar, D. clarkorum and D. dryada are morphologically different, and genetic studies (as the unpublished results mentioned by Fu, 1999) do not make the provenance of the specimens clear, and hence the correct identification of the supposed specimens of D. dryada used. There are no geographical clines in D. clarkorum. However, as stated by Schmidtler et al. (2002), there is an inverse relationship between altitude and dorsalia values in D. clarkorum. Both the general differentiation between populations and the scalation (dorsalia) appear statistically correlated with the altitude and also with latitude (being both factors not strictly the same). The correlation seems to be stronger with morphology in general (multiple scalation characters and head biometry) than only with dorsalia. In the case of the general differentiation among samples, it is also significantly correlated with temperatures during the activity period (April-September) and with precipitation during incubation (July-August). As these climatic parameters of temperature and precipitation are not directly correlated with the dorsalia variation, the relation with altitude (and perhaps latitude) must be linked to some other climatic parameter not studied here, perhaps solar radiation or evapotranspiration.

Restoration of two Carabidae (Coleoptera) species from the Sistema Ibérico Ranges (North-Central Iberian Peninsula): Nebria (Nebria) urbionensis Arribas, 1991 and Zabrus (Iberozabrus) cameranus Arribas, 1994, bonae species.

Two endemic taxa of the Northern Iberian System have been rescued from synonymy using the study of external morphology by means of morphometric analysis and genital anatomy. The causes that possibly led to these two taxa erroneously being identified as synonyms are analysed in this research. In the case of Nebria (Nebria) urbionensis versus Nebria (Nebria) vuillefroyi, their confused relationship was caused by the handling of incorrectly labelled specimens and the subsequent interpolation of distribution areas, which led to overestimating the extent of N. (N.) vuillefroyi to the detriment of recognizing N. (N.) urbionensis as a valid species. According to the criterion that is defended in this work, both taxa are steno-endemic and, therefore, deserve protection due to their reduced habitats. The principle of authority applied by experts, based on an error, may, in this case, have been amplified and contributed to chronify the error.                The second case under review is Zabrus (Iberozabrus) cameranus versus Zabrus (Iberozabrus) laurae, which in a recent study of genus Zabrus, were subjected to a totally unjustified synonymy. The origin of such a taxonomic decision must be sought in the concatenation of a series of errors: the number and origin of the specimens studied do not adequately justify the statements and conclusions expressed in the text, the use of a single character (internal sac of the aedeagus) while ignoring other morphological characters, an inadequate taxonomic praxis, and the elaboration of conclusions based on the lack of supposedly-derived characters (that is, relying on symplesiomorphies). All of this does not point towards an adequate reconstruction of the genus systematics.                The uni- and multivariate biometric study, together with the morphological features that are contributed in this work (added to those already recognized initially for these species), allow to affirm that, although the taxa in discussion are nearby species and possibly sister taxa, they are perfectly valid: Nebria (Nebria) urbionensis stat. res.; Zabrus (Iberozabrus) cameranus stat. res. In addition to the morphological differences, both species diverge respectively from N. (N.) vuillefroyi and Z. (I.) laurae by 2% of the COI 1 gene sequence. The geographical ranges of Nebria (N.) urbionensis and Zabrus (I.) cameranus are confined to the Sistema Ibérico Septentrional, and are separated by the high Duero Valley from the ranges of N. (N.) vuillefroyi and Z. (I.) laurae, which are located in the Central System.

Variation in body size and sexual size dimorphism in the most widely ranging lizard: testing the effects of reproductive mode and climate.

Reproductive mode, ancestry, and climate are hypothesized to determine body size variation in reptiles but their effects have rarely been estimated simultaneously, especially at the intraspecific level. The common lizard (Zootoca vivipara) occupies almost the entire Northern Eurasia and includes viviparous and oviparous lineages, thus representing an excellent model for such studies. Using body length data for >10,000 individuals from 72 geographically distinct populations over the species' range, we analyzed how sex-specific adult body size and sexual size dimorphism (SSD) is associated with reproductive mode, lineage identity, and several climatic variables. Variation in male size was low and poorly explained by our predictors. In contrast, female size and SSD varied considerably, demonstrating significant effects of reproductive mode and particularly seasonality. Populations of the western oviparous lineage (northern Spain, south-western France) exhibited a smaller female size and less female-biased SSD than those of the western viviparous (France to Eastern Europe) and the eastern viviparous (Eastern Europe to Far East) lineages; this pattern persisted even after controlling for climatic effects. The phenotypic response to seasonality was complex: across the lineages, as well as within the eastern viviparous lineage, female size and SSD increase with increasing seasonality, whereas the western viviparous lineage followed the opposing trends. Altogether, viviparous populations seem to follow a saw-tooth geographic cline, which might reflect the nonmonotonic relationship of body size at maturity in females with the length of activity season. This relationship is predicted to arise in perennial ectotherms as a response to environmental constraints caused by seasonality of growth and reproduction. The SSD allometry followed the converse of Rensch's rule, a rare pattern for amniotes. Our results provide the first evidence of opposing body size-climate relationships in intraspecific units.

Complex hybridization patterns in European pond turtles (Emys orbicularis) in the Pyrenean Region.

Hybrid zones are natural laboratories allowing insights in genetic processes like lineage diversification, speciation and introgression. Using large sampling, 15 microsatellite loci and a mitochondrial marker, we examined the Pyrenean contact zone of three pond turtle taxa (Emys orbicularis orbicularis, E. o. galloitalica, E. o. occidentalis). The Pyrenees are a biogeographically important region separating many lineages endemic to the Iberian Peninsula from their Western European counterparts. We discovered limited admixture, reflecting a complex biogeographic scenario. Simulations using Approximate Bayesian Computing supported that E. o. orbicularis invaded the Iberian Peninsula in the Holocene, circumventing the Pyrenees along the Mediterranean coast, and hybridized in the northern peninsula with the local coastal subspecies galloitalica, and to a lesser extent, with occidentalis. While E. o. occidentalis, and in particular E. o. orbicularis, expanded their ranges considerably during Holocene warming, E. o. galloitalica remained largely confined to its former Iberian refuge. Admixture among the three taxa is surprisingly low, and a future taxonomic investigation that includes the unstudied subspecies of E. orbicularis from North Africa, Eastern Europe and Asia has to determine whether their current status properly reflects their evolutionary divergence or whether certain taxa should be regarded as full species.

Reevaluation of the intraspecific variability in Darevskia parvula (Lantz Cyren, 1913): an integrated approach using morphology, osteology and genetics (Squamata: Lacertidae).

The intraspecific variability of Darevskia parvula (which has two classical subspecies easily identifiable by external characteristics, D. p. parvula and D. p. adjarica), was studied using various approaches including morphology (scalation and biometry), multivariate analyses (PCA, CDA, ANOSIM, UPGMA and MST), osteology, and molecular techniques. High mitochondrial distance, differences at the nuclear level and morphological distinctiveness warrant the specific status of both taxa, Darevskia parvula (Lantz Cyrén, 1913) and Darevskia adjarica (Darevsky Eiselt, 1980) stat. nov. A lectotype for D. parvula, originally described with syntypes of both species -D. parvula and D. adjarica- is designated. The uncorrected genetic distance between D. parvula and D. adjarica in the cytochrome b mitochondrial gene is 14.4% ± 1.9%. Intraspecific variability within D. parvula is very small (1.5% ± 0.5%), and was not detected in our samples of D. adjarica. The two species further differ by two mutations in the nuclear melano-cortin 1 receptor (mc1r) gene. Interestingly, past introgression of D. parvula mitochondrial haplotypes (5% ± 1% different to those currently known) into some D. adjarica has been detected in one locality; all the studied specimens of D. adjarica with mtDNA of D. parvula are unmistakably D. adjarica at the morphological and nuclear levels.Morphologically, there is almost no overlap between D. parvula and D. adjarica. These results are corroborated by CDA, MST and UPGMA trees. Specimens of the inland high mountain population of Ardahan (clearly D. adjarica in CDA, MST and UPGMA trees) occupy a somewhat intermediate position between both taxa in the PCA (when specimens and not populations as a whole are considered), but this morphological closeness may be attributed to the influence of climatic factors (continental conditions) on scalation of the specimens. Males appear to be more differentiated than females. Overlap among samples within each species is very marked; none can be separated clearly from its conspecifics. This is even more marked in D. parvula, which has a fairly small area compared to D. adjarica.Darevskia parvula and D. adjarica samples appear to be homogeneously clustered within species and well separated between the two species in the UPGMA trees. In males and females all the D. parvula samples are very similar and moderately differentiated. In males of D. adjarica, the most differentiated seems to be adjBorçka, the others all being clustered together, with adjÇaykara showing slightly more differentiation from the rest (adjOrtacalar, adjArdahan, adjIkizdere and adjÇermik).Darevskia adjarica females are also similarly distributed into two subgroups, one including Borçka, Çermik and Ardahan and the other including Ortacalar, Ikizdere and Çaykara. In both sexes, the inland Ardahan sample clearly belongs to D. adjarica.From the most connected MST samples, speculations can be made about areas of origin and expansion of the different taxa. Ortacalar (D. adjarica) and Hatila (D. parvula) are the most connected (morphologically more "central" in both taxa); in fact, both populations are relatively close, living on the northern (Black Sea) and southern (Anatolian) facing slopes, respectively of the Dogu Karadeniz Mountains (Kaçkar Mountains). This highlights these mountains, which rise from sea level up to nearly 4000 m asl. and have wide buffering possibilities against climate changes, as a zone of refuge and posterior dispersion of this species, and even of the original splitting into two taxa adapted to these different conditions, D. adjarica on the coast and D. parvula on the continental slope.Osteologically D. parvula and D. adjarica are very similar, although Georgian specimens from an isolated population (Atskuri) have closed clavicles not found in Turkish D. adjarica. Also, inland Ardahan D. adjarica have an extra vertebra in both males and females, compared to the other studied specimens from both species.The present study indicates that the situation in Turkey is that D. parvula is well differentiated and lives around the Çoruh River Valley, contoured by D. adjarica populations on the coastal-facing slopes of the Dogu Karadeniz Mountains on one side, and the Yalnizçam Mountains on the other side, where D. adjarica enters from Georgia as the opposite extreme of a geographic distribution. The attribution of more inland ranges to D. parvula or D. adjarica, as well as the detailed genetic structure of both taxa may be confirmed with more specific studies.

A new mountain lizard from Montes de León (NW Iberian Peninsula): Iberolacerta monticola astur ssp. nov. (Squamata: Lacertidae).

Iberolacerta populations from the Northern Montes de Leon (NML) were studied by means of external morphology (scalation and biometry), osteology and genetics (mtDNA and microsatellites), searching for their homogeneity ("intrazonalanalysis") and, once verified, comparing them with Iberolacerta monticola s. str. (from Central Cantabrian Mountains)and/. gal ani (from Southern Montes de Leon) ("extrazonal analysis") from neighboring areas.Our "intrazonal analysis" revealed discordances between the different approaches, especially the patterns of variation of nuclear microsatellites (congruent with external morphology) and mtDNA, namely a very low nuclear differentiation between relatively highly differentiated mtDNA lineages. The morphological approach was unable to discriminate any of the populations as significantly different from the others in the NML. Mitochondrial DNA revealed a haplotype lineage closely related to I. galani (MNL-II in our text) in some specimens of Sierra de Villabandfn and Suspiron, but these populations are morphologically indistinguishable from the main part of the other populations that belong to lineage NML-1,phylogenetically closer to/. monticola. After a separation from I. manti cola ca. 1.8 Mya, the populations in this geographic region must have suffered at least two different waves of gene flow from I. gal ani, the second one not much later than 0.5 Mya. Microsatellite results indicate that all the NML populations are genetically similar in terms of their nuclear genomes,independently of their mitochondrial differentiation (NML-I vs. NML-II haplotype groups). Since all the morphological and microsatellite evidences point towards the fact that, independently of the mitochondrial haplotypes that they bear (NML-1 or NML-II), there is only one taxon in the area, we describe it as: Iberolacerta monticola astur ssp. nov.Concerning the relationships of I. m. astur ssp. nov. with I. monticola s. str. and I. gal ani ("extra zonal analysis"), in the female analyses the new taxon centroid is closer to I. monticola s. str. than to I. gal ani (more similarity with I manticolas.str.), whereas in the male analyses the relationship is just the contrary (closer to I. gal ani, paralleling the direction of the hypothesized past hybridization). Moreover, in both sexes' ANOVA, I. m. astur ssp. nov. results more similar (lessP<0.05 differences) to I. galani than to I. monticola s. str. Osteologically, I. m. astur ssp. nov. is slightly more similar toI. monticola s. str. than to I. galani, especially in the squamosal bone, which is regularly arched (primitive shape). Genetically,as indicated above, the NML populations can be subdivided in two groups according to their mitochondrial DNA,namely NML-I (bearing clearly differentiated haplotypes, phylogenetically closer to I. monticola) and NML-II (whose haplotypes could have been mistaken for those of an I. gal ani population). This mitochondrial subdivision has at most a subtle nuclear correlate, however. According to the nuclear microsatellite markers, all the NML populations belong to a single group(/. m. astur ssp. nov.), which would be more similar to I. gal ani than to I monticola, with NML-II populations lying closer to I. galani than those from the NML-I group and, correspondingly, more distant from I. monticola. The discordant phylogenetic signal of mitochondrial and nuclear markers is discussed in terms of past introgression events and sex-biases in phylopatry and dispersion in these species. Iberolacerta manti cola astur ssp. nov., inhabits the Northern Montes de Leon (Sierra de Gistreo sensu latissimo ): Gistredo,Catoute, Tambaron, Nevadfn, Villabandfn (or Macizo del Alto de Ia Canada), Arcos del Agua (or Fernan Perez),Tiendas and Suspiron, mainly in quartzite and slate rock substrates. Its current distribution, cornered in the NW of theNorthern part of the Montes de Leon, suggests a possible competitive exclusion between this taxon and/. galani, as the galani haplotypes (NML-II) appear cornered in the most harsh and continental areas, speaking also about a, even in the past, very limited presence of this species in the area that probably was soon absorbed by I. m. astur ssp. nov. (with NMLI haplotypes). Variation in watershed limits (especially with l montico/a s. str. in the North) and Pleistocene climatic oscillations(with I. gal ani in the South) probably played a crucial role in isolation of the different Iberolacerta colonizationwaves in this zone. These changes in the boundaries among watersheds limited the contact between the NML and the main Cantabrian Mountains, restricting to narrow points (different along time) the contact between the two ranges, and thus,the areas for possible contact between I. m. astur ssp. nov. and I. monticola s. str. (see Fig. lB). The origin of this tax on dates back to the end of Pliocene or Lower Pleistocene (around 1.8 Mya), according to mtDNA divergence. On the other side, climatic oscillations allowed expansion and contact with the more continental harsh climate-dwelling I. gal ani.

Isolation and characterization of two satellite DNAs in some Iberian rock lizards (Squamata, Lacertidae).

Satellite DNAs represent a large portion of all high eukaryotic genomes. They consist of numerous very similar repeated sequences, tandemly arranged in large clusters up to 100 million base pairs in length, usually located in the heterochromatic parts of chromosomes. The biological significance of satDNAs is still under discussion, but most of their proposed functions are related to heterochromatin and/or centromere formation and function. Because information about the structure of reptilian satDNA is far from exhaustive, we present a molecular and cytogenetic characterization of two satDNA families in four lacertid species. Two families of tandemly repeated DNAs, namely TaqI and HindIII satDNAs, have been cloned and sequenced from four species belonging to the genus Iberolacerta. These satDNAs are characterized by a monomer length of 171-188 and 170-172 bp, and by an AT content of 60.5% and 58.1%, respectively. FISH experiments with TaqI satDNA probe produced bright signals in pericentromeric regions of a subset of chromosomes whereas all the centromeres were marked by HindIII probe. The results obtained in this study suggest that chromosome location and abundance of satDNAs influence the evolution of these elements, with centromeric families evolving tenfold faster than interstitial/pericentromeric ones. Such different rates render different satellites useful for phylogenetic investigation at different taxonomic ranks.

Causes and evolutionary consequences of population subdivision of an Iberian mountain lizard, Iberolacerta monticola.

AIM: The study of the factors that influence population connectivity and spatial distribution of genetic variation is crucial for understanding speciation and for predicting the effects of landscape modification and habitat fragmentation, which are considered severe threats to global biodiversity. This dual perspective is obtained from analyses of subalpine mountain species, whose present distribution may have been shaped both by cyclical climate changes over ice ages and anthropogenic perturbations of their habitats. Here, we examine the phylogeography, population structure and genetic diversity of the lacertid lizard Iberolacerta monticola, an endemism considered to be facing a high risk of extinction in several populations. LOCATION: Northwestern quadrant of the Iberian Peninsula. METHODS: We analyzed the mtDNA variation at the control region (454 bp) and the cytochrome b (598 bp) loci, as well as at 10 nuclear microsatellite loci from 17 populations throughout the distribution range of the species. RESULTS: According to nuclear markers, most sampling sites are defined as distinct, genetically differentiated populations, and many of them show traces of recent bottlenecks. Mitochondrial data identify a relatively old, geographically restricted lineage, and four to six younger geographically vicariant sister clades, whose origin may be traced back to the mid-Pleistocene revolution, with several subclades possibly associated to the mid-Bruhnes transition. Geographic range fragmentation of one of these clades, which includes lowland sites, is very recent, and most likely due to the accelerated loss of Atlantic forests by human intervention. MAIN CONCLUSIONS: Altogether, the data fit a "refugia within refugia" model, some lack of pattern uniformity notwithstanding, and suggest that these mountains might be the cradles of new species of Iberolacerta. However, the changes operated during the Holocene severely compromise the long-term survival of those genetic lineages more exposed to the anthropogenic perturbations of their habitats.

Review of the systematics, distribution, biogeography and natural history of Moroccan amphibians.

The amphibian fauna of the Kingdom of Morocco was traditionally regarded as poor and closely related to its European counterpart. However, an increase in research during the last decades revealed a considerable degree of endemism amongst Moroccan amphibians, as well as phenotypic and genotypic inter- and intraspecific divergence. Despite this increase in knowledge, a comprehensible overview is lacking while several systematic issues have remained unresolved. We herein present a contemporary overview of the distribution, taxonomy and biogeography of Moroccan amphibians. Fourteen fieldtrips were made by the authors and colleagues between 2000 and 2012, which produced a total of 292 new distribution records. Furthermore, based on the results of the present work, we (i) review the systematics of the genus Salamandra in Morocco, including the description of a new subspecies from the Rif- and Middle Atlas Mountains, Salamandra algira splendens ssp. nov.; (ii) present data on intraspecific morphological variability of Pelobates varaldiiand Pleurodeles waltl in Morocco; (iii) attempt to resolve the phylogenetic position of Bufo brongersmai and erect a new genus for this species, Barbarophryne gen. nov.; (iv) summarize and assess the availability of tadpole-specific characteristics and bioacoustical data, and (v) summarize natural history data.

External morphology and osteology of Darevskia rudis (Bedriaga, 1886), with a taxonomic revision of the Pontic and Small-Caucasus populations (Squamata: Lacertidae).

A broad sample of Darevskia rudis from the main part of its range was reviewed with regard to external morphology (discriminant, UPGMA, MST and ANOVA analyses) and osteology. Darevskia bithynica is raised to species rank, with two subspecies: D. b. bithynica and D. b. tristis. The other subspecies are fairly similar (D. r. rudis being the most different). Two singular populations are described as subspecies: D. r. mirabilis ssp. nov. from Kaçkar Mountains, geographically adjoins the otherwise different D. r. bischoffi and D. r. bolkardaghica ssp. nov., which is geographically isolated but that seems to be very closely related to D. r. obscura.