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A new species of Acanthodactylus, A. tilburyi, is described from north and central Saudi Arabia. It occurs on aeolian sand slopes and is most closely related to A. gongrorhynchatus and A. haasi.

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Differences in surface structure (ober- hautchen) of body scales of lacertid lizards involve cell size, shape and surface profile, presence or absence of fine pitting, form of cell margins, and the occurrence of longitudinal ridges and pustular projections. Phylogenetic information indicates that the primitive pattern involved narrow strap-shaped cells, with low posteriorly overlapping edges and relatively smooth surfaces. Deviations from this condition produce a more sculptured surface and have developed many times, although subsequent overt reversals are uncommon. Like variations in scale shape, different patterns of dorsal body microornamentation appear to confer different and conflicting performance advantages. The primitive pattern may reduce friction during locomotion and also enhances dirt shedding, especially in ground-dwelling forms from moist habitats. However, this smooth microornamentation generates shine that may compromise cryptic coloration, especially when scales are large. Many derived features show correlation with such large scales and appear to suppress shine. They occur most frequently in forms from dry habitats or forms that climb in vegetation away from the ground, situations where dirt adhesion is less of a problem. Microornamentation differences involving other parts of the body and other squamate groups tend to corroborate this functional interpretation. Microornamentation features can develop on lineages in different orders and appear to act additively in reducing shine. In some cases different combinations may be optimal solutions in particular environments, but lineage effects, such as limited reversibility and different developmental proclivities, may also be important in their genesis. The fine pits often found on cell surfaces are unconnected with shine reduction, as they are smaller than the wavelengths of most visible light.

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In the present work, we use an exceptional database including 5,359 records of 101 species of Oman’s terrestrial reptiles together with spatial tools to infer the spatial patterns of species richness and endemicity, to infer the habitat preference of each species and to better define conservation priorities, with especial focus on the effectiveness of the protected areas in preserving this unique arid fauna. Our results indicate that the sampling effort is not only remarkable from a taxonomic point of view, with multiple observations for most species, but also for the spatial coverage achieved. The observations are distributed almost continuously across the two-dimensional climatic space of Oman defined by the mean annual tempera- ture and the total annual precipitation and across the Principal Component Analysis (PCA) of the multivariate climatic space and are well represented within 17 out of the 20 climatic clusters grouping 10% of the explained climatic variance defined by PC1 and PC2. Species richness is highest in the Hajar and Dhofar Mountains, two of the most biodiverse areas of the Arabian Peninsula, and endemic species richness is greatest in the Jebel Akhdar, the highest part of the Hajar Mountains. Oman’s 22 protected areas cover only 3.91% of the country, including within their limits 63.37% of terrestrial reptiles and 50% of all endemics. Our analy- ses show that large areas of the climatic space of Oman lie outside protected areas and that seven of the 20 climatic clusters are not protected at all. The results of the gap analysis indi- cate that most of the species are below the conservation target of 17% or even the less restrictive 12% of their total area within a protected area in order to be considered adequately protected. Therefore, an evaluation of the coverage of the current network of protected areas and the identification of priority protected areas for reptiles using reserve design algorithms are urgently needed. Our study also shows that more than half of the species are still pending of a definitive evaluation by the International Union for Conservation of Nature (IUCN).

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The terrestrial reptiles oft he UAE the lizards, snakes and a single species of amphisbaenian or worm lizard. There are no extant native crocodiles, tortoises or freshwater terrapins. Lizards, snakes and amphisbaenians are all classified under the reptilian order Squamata, in the suborders Sauria, Serpentes and Amphisbaenia respectively. Characterised by their dry, scaly skin, which protects them from drying out, and by their reliance on external heat sources to maintain their body temperatures, reptiles are well-suited to hot and arid areas. In Arabia, reptiles are a major component of the desert and mountain ecosystems and a total of at least 54 species of terrestrial reptile are found in the UAE. So far, a comprehensive handbook covering all of the UAE reptiles in detail is not available. The Handbook to Middle East Amphibians and Reptiles (Leviton et al. 1992) does not cover the species of the mountains or Northern Emirates and gives little information on natural history. Useful general sources of information are Wild about Reptiles (Jongbloed 2000) and Terrestrial Reptiles of Abu Dhabi (Baha El Din 1986).

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Mitochondrial DNA sequences consisting of 645 sites from the 12S rRNA and 16S rRNA genes were used to estimate the phylogeny of 15 of the 32 species of spiny-footed lizards Acanthodactylus. The resultant tree has similarities to that produced from a differentially weighted data set of 32 morphological characters but there are also significant differences. However, combined analysis of molecular and morphological data sets produces the same tree topology as DNA sequence alone. The molecular data confirm that there are distinct eastern and western clades within Acanthodactylus, but place A. boskianus in the former while the A. scutellatus group constitutes a third clade. Species for which only morphological information is available were integrated with the combined tree to give a provisional phylogeny for 31 species. This phylogeny indicates that the ancestor of existing Acanthodactylus probably originated in south-west Asia and that North Africa was invaded by more than one lineage of the genus. It also suggests that soft aeolian sand habitats may have been independently occupied more than once. Molecular data provide independent evidence that the differential weighting of morphological characters in past analyses was appropriate.

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The Afrotropical element in the Arabian herpetofauna is concentrated in the southwestern mountainous region, whereas everywhere else in the peninsula the reptile fauna is Saharo-Sindian. There is a high degree of correspondence between the reptile faunas of the Yemens and Somalia. A remarkable faunistic resemblance also exists between the relict faunas of SW Arabia and Morocco. Three evolutionary levels can be distinguished among Ethiopian taxa in Arabia and are interpreted as evidence of different times of faunal contact: 1. Old relicts (genus level) of a Palaeogene (pre continental drift) Arabian/North African fauna (Pristurus, Trogonophidae); 2. Endemic species closely related to East African species (most probably Miocene); 3. Species distributed on both sides of the Bäb al-Mandab (Pleistocene). Contrary to the Saharo-Sindian faunal elements, there is good evidence that groups 2 and 3 used a landbridge across the Bäb al-Mandab for faunal exchange: the Miocene closure of the southern outlet of the Red Sea and a Pleistocene land connection due to eustatic sea level change.

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In this third paper on the herpetofauna of Oman, three families are treated: eleven Lacertidae, six Scincidae and one varanid. New records, notes on ecology and localities are combined with data from literature.

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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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Field observations on Acanthodactylus schmidti, A. gongrorhynchatus and A. haasi are recorded. Areas of sympatry occur between A. schmidti and A. gongrorhynchatus; A. gongrorhynchatus is sympatric with A. haasi and all three species occur in sympatry in eastern Saudi Arabia. Behaviour and ecology have been observed where all the three species are sympatric. Known distribution is recorded for the three species with a map for A. gongrorhynchatus and A. haasi.

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Die vorliegende Revision betrifft die Gattung Acanthodactylus (Damilie Lacertidae), die die Trocken- und Wüstengebiete des nördlichen Afrika und des südwestlichen Asiens bewohnt, mit Randpopulationen auf der Iberischen Halbinsel und auf Zypern. Mehr als 6000 Exemplare der Gattung, aus den bedeutendsten europäischen und amerikanischen Sammlungen, wurden untersucht. Zusätzlich wurden über 450 Röntgenaufnahmen für osteologische Untersuchungen ausgewertet. Die historische Übersicht behandelt in chronologischer Reihenfolge alle Arbeiten, die sich mit der Gattung Acanthodactylus beschäftigen, mit besonderer Berücksichtigung taxonomischer Studien. Ein beigegebener Bestimmungsschlüssel ermöglicht die Determination aller Arten der Gattung. Eine Reihe äußerer (Größe und Proportionen, Pholidose, Färbung und Zeichnung) und innerer (d.h. osteologischer) Merkmale wurde im Hinblick auf ihre Variabilität untersucht. Dann wurde ein Land ausgesucht, z.B. Ägypten, aus dem eine gute Materialbasis zur Verfügung stand. Für einen bestimmten Fundort in diesem Lande wurden sodann einige Kombinationen von Merkmalszuständen ermittelt, die sich aus dem Auftreten verschiedener Arten ergaben. Derselbe Vorgang wurde sodann auf den Rest Ägyptens übertragen, und die Merkmalskombinationen stellten sich als übereinstimmend heraus; sie erlaubten dadurch eine sichere Zuordnung von Tieren zu folgen Arten: A. boskianus, A. scutellatus und A. pardalis. Durch die Ausdehnung der Untersuchung nach Westen und Osten kamen weitere Taxa hinzu. Besonderer Aufmerksamkeit wurde diesen Merkmalskombinationen im Hinblick auf sympatrisches oder allopatrisches Auftreten der betroffenen Arten gezollt, mit dem Ergebnis, daß es in einigen Fällen möglich war, abzusichern, daß es sich um Populationen derselben Art handelt. Die Gattung Acanthodactylus wurde in mehrere Artengruppen gegliedert, die sich durch engere Beziehungen ihrer Arten untereinander auszeichnen. Die erste ist die micropholis-Gruppe mit der einzigen Art A. micropholis. Sie wird als die ursprünglichste der gesamten Gattung angesehen. Eine weitere Gruppe ist die boskianus-Gruppe, mit den Arten A. boskianus und A. schreiberi. Erstere wird ausführlich analysiert im Hinblick auf ihre außerordentlich große geographische Variabilität. Die yemenicus-Gruppe besiedelt die Arabische Halbinsel und besteht aus A. yemenicus sp.n., A. masirae, A. opheodurus und A. felicis. Eine weitere Gruppe ist die tristrami-Gruppe mit den Arten A. tristrami und A. robustus. Für erstere wird die Validität der Unterart orientalis verneint, die für iracensis dagegen bejaht. In die grandis-Gruppe wird hier nur A. grandis gestellt, während A. fraseri als dessen Synonym aufgefaßt wird. Die erythrurus-Gruppe enthält A. erythrurus, A. savignyi, A. blanci, A. boueti und A. guineensis. Letzterer rangierte bislang in der Gattung Eremias, gehört aber nach den hier vorgelegten Befunden in die erythrurus-Gruppe von Acanthodactylus. In der pardalis-Gruppe sind enthalten: A. pardalis, A. bedriagai, A. maculatus, A. spinicauda und A. busacki sp.n. aus Marokko. Die scutellatus-Gruppe besteht aus A. scutellatus, A. aureus, A. dumerili und A. longipes. Die letzte Gruppe ist die cantoris-Gruppe mit den Arten A. cantoris, A. arabicus, A. schmidti, A. blanfordi, A. gongrorhynchatus und A. haasi. Eine Bibliographie über die Gattung beschließt die Arbeit. Für jede Art werden Diagnosen, Verbreitungskarten, Synonymien, Beschreibungen und Materiallisten der untersuchten Tiere sowie auch Strichzeichnungen gegeben.

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Aim: Deserts are generally perceived as areas of low diversity, and hence receive little attention from researchers and conservationists. Squamates are the dominant group of vertebrates in arid regions, and as such represent an ideal model to study biodiversity patterns in these areas. We examine spatial patterns of diversity, evolutionary history and endemism of terrestrial squamates of the Arabian Peninsula and test hypotheses on the role of topography and history of isolation so as to identify possible environmental drivers of diversification. Location: The Arabian Peninsula. Taxon: Squamate reptiles (Squamata; lizards and snakes). Methods: We generated distribution maps for all Arabian squamate species (including yet undescribed) and reconstructed their phylogenetic relationships using existing and newly produced genetic data for nearly all the species. We assessed patterns of the distribution of species richness, phylogenetic diversity and phylogenetic en demism across the peninsula to identify areas that could be considered evolutionary or endemicity hotspots for squamates. We evaluated community turnover across the peninsula and assessed the possible environmental drivers affecting the diversity of Arabian squamates in a regression framework. Results: The main hotspots of Arabian squamate diversity are mostly along the mountains that rim the peninsula while the most arid, central regions support a low diversity of species. The distribution of the phylogenetic diversity mirrors that of the species richness. Phylogenetic endemism is also highest in the mountains, especially when only endemic species are analysed. The deserts of northern Arabia are poor in terms of species richness and they show low connectivity to the peninsular communities. Topographic heterogeneity is the strongest predictor for Arabian squamates, followed by elevation. There is no correlation between richness and temperature. Main conclusions: The mountains of Arabia support rich and unique squamate communities that are dominated by local radiations of closely related and narrow-ranging species. In particular, the Asir Mountains of SW Arabia, Dhofar Province of Oman and the Hajar Mountains of northern Oman and UAE show unprecedented levels of squamate endemism and phylogenetic endemism. While many generalist species range across Arabia, a low number of species is shared between the peninsula and mainland Asia, indicating an effective isolation of the Arabian fauna. Squamate richness is highest in heterogeneous, topographically complex habitats.

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This paper provides an updated checklist of the United Arab Emirates (UAE) native and alien herpetofauna. The UAE, while largely a desert country with a hyper-arid climate, also has a range of more mesic habitats such as islands, mountains, and wadis. As such it has a diverse native herpetofauna of at least 72 species as follows: two amphibian species (Bufonidae), five marine turtle species (Cheloniidae [four] and Dermochelyidae [one]), 42 lizard species (Agamidae [six], Gekkonidae [19], Lacertidae [10], Scincidae [six], and Varanidae [one]), a single amphisbaenian, and 22 snake species (Leptotyphlopidae [one], Boidae [one], Colubridae [seven], Hydrophiidae [nine], and Viperidae [four]). Additionally, we recorded at least eight alien species, although only the Brahminy Blind Snake (Ramphotyplops braminus) appears to have become naturalized. We also list legislation and international conventions pertinent to the herpetofauna.

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Acanthodactylus lizards are among the most diverse and widespread diurnal reptiles in the arid regions spanning from North Africa across to western India. Acanthodactylus constitutes the most species-rich genus in the family Lacertidae, with over 40 recognized species inhabiting a wide variety of dry habitats. The genus has seldom undergone taxonomic revisions, and although there are a number of described species and species-groups, their boundaries as well as their interspecific relationships are largely unresolved. We constructed a multilocus phylogeny, combining data from two mitochondrial (12S, cytb) and three nuclear (MC1R, ACM4, c-mos) markers for 302 individuals belonging to 36 known species, providing the first large-scale time-calibrated molecular phylogeny of the genus. We evaluated phylogenetic relationships between and within species-groups, and assessed Acanthodactylus biogeography across its known range. Acanthodactylus cladogenesis is estimated to have originated in Africa due to vicariance and dispersal events from the Oligocene onwards. Radiation started with the separation into three clades: the Western and scutellatus clades largely distributed in North Africa, and the Eastern clade occurring mostly from Arabia to south-west Asia. Most Acanthodactylus species diverged during the Miocene, possibly as a result of regional geological instability and climatic changes. We support most of the current taxonomic classifications and phylogenetic relationships, and provide genetic validity for most species. We reveal a new distinct blanfordii species-group, suggest new phylogenetic positions (A. hardyi, A. masirae), and synonymize several species and subspecies (A. lineomaculatus, A. boskianus khattensis and A. b. nigeriensis) with their phylogenetically closely-related species. We recommend a thorough systematic revision of taxa exhibiting high levels of intraspecific variability as well as clear evidence of phylogenetic complexity such as A. guineensis, A. grandis, A. dumerilii, and A. senegalensis and the pardalis and erythrurus species-groups.

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The aim of this study was to determine if divergence in habitat use among lacertid lizards is paralleled by morphological differentiation. For 35 lacertid species, we measured body, head and limb dimensions. Habitat use was inferred from the literature: ground-dwelling on open terrain, ground-dwelling in vegetated areas, shrub-climbing, tree-climbing, saxicolous (i.e. rock-climbing). Traditional (i.e. non-phylogenetic) statistical analyses suggest morphological differences among species groups with different habitat use. Ground-dwelling species from open habitats tend to have longer femurs, tibiae and humeri (relative to body length) than other groups. Cursorial (i.e. level-running) species have relatively high heads and trunks compared to climbing species. These differences follow biomechanical predictions and it is tempting to consider tham as adaptations to habitat use. However, phylogenetic analyses of the data fail to establish a clear relationship between habitat use and morphology in the data set considered. There is a weak indication that the differences in head and trunk height have evolved as an adaptation to different habitat use, but the differences in relative limb dimensions among species groups with different habitat use vanish. Either adaptation of limb dimensions to habitat use has not occurred in lacertid lizards, or our methods are unable to demonstrate such an adaptation. We show that uncertainties in the topology of the phylogenetic tree used are unlikely to influence the outcome of our study. We also address the fact that habitat use is often similar in different branches of the phylogenetic tree, and the consequences this may have for the power of our statistical analyses.