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In this study we review the species of lizards in the genus Mesalina (Lacertidae) and present a new key for their identification. We also obtained five photos of each species from the British Museum of Natural History that illustrate the dorsal, lateral (right and left), and ventral views of the head and the femoral pores of each species. The papers with the original descriptions of each species were reviewed and used in preparation of the key. Some remarks about the habitat, natural history, updated distribution map and previous taxonomic changes are explained.

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Aim We explored the phylogenetic relationships of species of Mesalina, using one nuclear and two mitochondrial loci. This genus of lacertid lizards is widely distributed in North Africa and the Middle East and our goal was to develop a scenario capable of explaining the current distribution and evolutionary patterns within the genus in the context of the wider historical biogeography of the region. Location North Africa and the Middle East. Methods The assembled dataset consisted of 193 Mesalina individuals, representing 12 species distributed across the geographical range of the genus. Bayesian and maximum likelihood methods were used to support phylogenetic inferences on two mitochondrial (cytochrome b and 16S ribosomal RNA) and one nuclear (beta-fibrinogen intron 7) markers. Palaeogeographical and palaeoclimatic data were used to support the inferred phylogeographical patterns. Results Mesalina lizards exhibit high genetic diversity and complex phylogenetic patterns, leading to an unsatisfactory systematic hypothesis of one paraphyletic and three polyphyletic traditional species. The estimated divergence times place the origin of the genus in the early Miocene (c. 22 Ma) and the divergence of most currently recognized species in the middle to late Miocene. The inferred ancestral distribution suggests that the genus and most of its species originated somewhere in Arabia or the Middle East, with the exception of the Mesalina olivieri complex, which may be of African origin. Main conclusions Phylogenetic reconstruction based on the three loci studied suggests a higher than expected cryptic diversity of Mesalina in North Africa and the Middle East. We suggest that the tectonic movements of the Arabian plate, coupled with the climatic changes occurring since the Miocene, may be responsible for the phylogeographical patterns of North African and Middle Eastern Mesalina.

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We provide the first complete list of the present and lost amphibian and reptile type specimens of the Hessisches Landesmuseum Darmstadt and the Museum Wiesbaden Naturhistorische Landessammlung. The Darmstadt collection cur- rently houses primary types of 5 taxa (holotypes) and secondary types of addi- tional 15 taxa (paratypes). The Wiesbaden collection includes primary types of 13 taxa (8 represented by holotypes, 4 by syntypes and 1 by lectotype). Furthermore, the primary types of 6 taxa formerly housed at the Museum Wiesbaden are consid- ered lost. In several cases, we comment on the current status of the taxa present in the collections. Bufo spinulosus var. arapensis Andersson, 1908 was obviously over- looked and neglected in the literature. It is here considered a junior synonym of Chaunus spinulosus (Wiegmann, 1834). The largest specimen of the type series is designated as lectotype (MWNH 153/1). The current status of Hylambates rufus var. aubryioides Andersson, 1908, as a junior synonym of Leptopelis modestus (Werner, 1898) is rejected.

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Aim Body size is instrumental in influencing animal physiology, morphology, ecology and evolution, as well as extinction risk. I examine several hypotheses regarding the influence of body size on lizard evolution and extinction risk, assessing whether body size influences, or is influenced by, species richness, herbivory, island dwelling and extinction risk. Location World-wide. Methods I used literature data and measurements of museum and live specimens to estimate lizard body size distributions. Results I obtained body size data for 99% of the world`s lizard species. The body size–frequency distribution is highly modal and right skewed and similar distributions characterize most lizard families and lizard assemblages across biogeographical realms. There is a strong negative correlation between mean body size within families and species richness. Herbivorous lizards are larger than omnivorous and carnivorous ones, and aquatic lizards are larger than non-aquatic species. Diurnal activity is associated with small body size. Insular lizards tend towards both extremes of the size spectrum. Extinction risk increases with body size of species for which risk has been assessed. Main conclusions Small size seems to promote fast diversification of disparate body plans. The absence of mammalian predators allows insular lizards to attain larger body sizes by means of release from predation and allows them to evolve into the top predator niche. Island living also promotes a high frequency of herbivory, which is also associated with large size. Aquatic and nocturnal lizards probably evolve large size because of thermal constraints. The association between large size and high extinction risk, however, probably reflects a bias in the species in which risk has been studied.

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Many animals display complex colour patterns that comprise several adjacent, often contrasting colour patches. Combining patches of complementary colours increases the overall conspicuousness of the complex pattern, enhancing signal detection. Therefore, selection for conspicuousness may act not only on the design of single colour patches, but also on their combination. Contrasting long- and short-wavelength colour patches are located on the ventral and lateral surfaces of many lacertid lizards. As the combination of long- and short-wavelength-based colours generates local chromatic contrast, we hypothesized that selection may favour the co-occurrence of lateral and ventral contrasting patches, resulting in complex colour patterns that maximize the overall conspicuousness of the signal. To test this hypothesis we performed a comparative phylogenetic study using a categorical colour classification based on spectral data and descriptive information on lacertid coloration collected from the literature. Our results demonstrate that conspicuous ventral (long wavelength-based) and lateral (short wavelength-based) colour patches co-occur throughout the lacertid phylogeny more often than expected by chance, especially in the subfamily Lacertini. These results suggest that selection promotes the evolution of the complex pattern rather than the acquisition of a single conspicuous colour patch, possibly due to the increased conspicuousness caused by the combination of colours with contrasting spectral properties.

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The lacertid lizards of the genus Mesalina inhabit the arid regions of the Old World, from North Africa to NW India. Of the 19 recognized species within the genus, eleven occur in Arabia. In this study, we explore the genetic variability and phylogeographic patterns of the less studied M. adramitana group from southern Arabia and the Socotra Archipelago within the phylogenetic and biogeographic context of the entire genus. Our unprecedented sampling extends the distribution ranges of most Mesalina species and, for the first time, sequences of M. ayunensis are included in a phylogenetic analysis. We perform analyses of concatenated multilocus datasets and species trees, conduct species delimitation analyses, and estimate divergence times within a biogeographic framework. Additionally, we inferred the environmental suitability and identified dispersal corridors through which gene flow is enabled within M. adramitana. Our results show that the Socotra Archipelago was colonized approximately 7 Mya by a single oversea colonization from mainland Arabia. Then, an intra-archipelago dispersal event that occurred approximately 5 Mya resulted in the speciation between M. balfouri, endemic to Socotra, Samha and Darsa Islands, and M. kuri, endemic to Abd al Kuri Island. Similar to previous studies, we uncovered high levels of genetic diversity within the M. adramitana species-group, with two highly divergent lineages of M. adramitana living in allopatry and adapted to locally specific climatic conditions that necessitate further investigation.

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Few DNA barcoding studies of squamate reptiles have been conducted. Due to the significance of the Socotra Archipelago (a UNESCO Natural World Heritage site and a biodiversity hotspot) and the conservation interest of its reptile fauna (94% endemics), we performed the most comprehensive DNA barcoding study on an island group to date to test its applicability to specimen identification and species discovery. Reptiles constitute Socotra`s most important vertebrate fauna, yet their taxonomy remains under-studied. We successfully DNA-barcoded 380 individuals of all 31 presently recognized species. The specimen identification success rate is moderate to high, and almost all species presented local barcoding gaps. The unexpected high levels of intra-specific variability found within some species suggest cryptic diversity. Species richness may be under-estimated by 13.8-54.4%. This has implications in the species` ranges and conservation status that should be considered for conservation planning. Other phylogenetic studies using mitochondrial and nuclear markers are congruent with our results. We conclude that, despite its reduced length (663 base pairs), cytochrome c oxidase 1, COI, is very useful for specimen identification and for detecting intra-specific diversity, and has a good phylogenetic signal. We recommend DNA barcoding to be applied to other biodiversity hotspots for quickly and cost-efficiently flagging species discovery, preferentially incorporated into an integrative taxonomic framework.