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Some 500 Dhofar reptiles and amphibians are discussed and a minimum of 48 terrestrial species recognised for the area of which 5 were previously undescribed; these are a gecko, Hemidactylus lemurinus, and the lacertids Acanthodactylus felicis, A. opheodurus,A. masirae and Mesalina ayunensis; a new subspecies of gecko from north Oman, Bunopus spatalurus hajarensis is also reported. Various other species are reviewed; it appears that Bunopus abudhabi is a synonym of B. blanfordi, which is probably conspecific with B. tuberculatus, Hemidactylus parkeri is regarded as a subspecies of H. turcicus, the Arabian agamas of the Agama cyanogaster group are shown to include 2 species to which the names adramitana and yemenensis are applicable although their status relative to African populations in the group is not clear; A. jayakari is conspecific with A. flavimaculata, and A. neumanni with A. sinaita; Chamaeleo chamaeleon orientalis is similar to more northern populations of C. chamaeleon but C. c. arabicus is very well differentiated and may be a separate species, the use of genitalia in the classification of Acanthodactylus is emphasised and A. arabicus, A. blanfordi and A. schmidti are all given full species status; the recognition of Mesalina as a genus indepemdemt of Eremias is confirmed, it is suggestes that Atractaspis engeddensis may be conspecific with A. microlepidota and that Lytorhynchus gaddi is a synonym of L. diadema; the distinctive population of Echis carinatus in Dhofar appears to be closely related to those in south-west Arabia and adjoining Africa but animals from northern Oman and the rest of south-west Asia are very different. Additional specimens are reported of Bunopus s. spatalurus and Coluber thomasi, both previously known from only 2 individuals. Geographical variations of a number of species is discribed including 3 geckos that show very considerable differences within southern Dhofar: Hemidactylus homocolepis, H. yerburii and Tropiocolotes scorteccii. Observations on the ecology of many species are noted, especially for the aberrant gecko genus Pristurus, one species of which, P. carteri, behaves like a small, ground-dwelling diurnal agamid. Resource partition, at least amongst the lizards, appears to be largely based on parameters of time, food (especially prey size), hunting method and space. A number of forms occourring in both noreth Oman and Dhofar show differences in niche in the two areas apparently related to the presence of absence of a competitor. Several species are recorded from Dhofar for the first time including Bunopus spatalurus, Hemidactylus flaviviridis, H. turcicus parkeri, Pristurus minimus, Agama adramitana, Acanthodactylus boskianus,Mabuya tessellata, Leptotyphlops macrorhynchus and Lytorhynchus diadema. The herpetofauna of the area can be divided into a largely northern element of desert-adapted forms widespread in the Arabian peninsula and a more peripheral element in the south which shows considerably more affinity to south-west Arabia than to northern Oman. No reptile of amphibian endemics occur in the forested areas of Dhofar but 3 species present in the drymesic habitats on the north side of the mountains may be restricted to the region. Acanthodactylus opheodurus, Acanthodactylus felicis, Acanthodactylus masirae, Acanthodactylus boskianus, Acanthodactylus schmidti, Mesalina adramitana, Mesalina ayunensis.

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The ability to shed (autotomize) all or part of the tail, usually in response to predator attack, and often to subsequently regenerate it is widespread in lizards and amphisbaenians and also occurs in a few snakes and in the tuatara. Most species possess a sophisticated intravertebral autotomy mechanism which seems to be primitive in the Squamata. This appears to have been independently lost in members of many groups, but some agamids and snakes have regained the ability to shed their tails by a simpler intervertebral means and a -number of agamids have also redeveloped tail regeneration as well. Breakable tails are used to evade capture in two main ways: by enabling reptiles to break away from predators that have grasped them by the tail and by providing a distraction which deflects the attention of the attacker away from the vulnerable head and body. It is argued that loss of caudal autotomy has occurred when the costs of tail shedding outweigh its benefits. Likely costs include the expense of regrowing the tail and the loss of a variety of possible tail functions that may cause partial incapacitation, at least until the tail regenerates. Benefits of autotomy are liable to be low if predation is rare, if the animal is able to protect itself effectively in other ways, if it is too slow to evade further pursuit after the tail is shed, or if the tail is small or unpalatable and consequently not likely to distract a predator. Benefit variation may well be greater than cost variation and therefore more important in initiating the loss of autotomy mechanisms. Many taxa that do not shed the tail appear to conform to the above interpretation, but in some cases, such as the Platynota, Agamidae and Chamaeleonidae, lack of intravertebral autotomy may reflect the history of these groups rather than being a direct result of present ecological pressures. The distribution of intervertebral autotomy in the Agamidae suggests that it may have evolved only in rather special circumstances where tail fragility is advantageous even in the absence of the ability to regenerate. Restriction ot autotomy planes to the tail-base, so that the whole organ is lost, a condition found in a number of relatively slow-moving geckoes, is interpreted as a means of ensuring that enough of the tail is shed to distract a predator from further pursuit. The stimulus necessary to induce autotomy can vary rapidly in individual lizards and at least some of these changes probably maximize the effectiveness of the tail-shedding mechanism. Differences in the readiness with which all or part of the tail is shed exist between species and are likely to reflect the balance of costs and benefits in particular cases. Variations in incidence of broken tails between species and populations may be due to such differences in fragility but many other factors may play a part, including the age structure of samples, incidence of unsuccessful attacks by predators and ability to evade predators after autotomy. There is a clear tendency for climbing lizards, especially those living on rock surfaces, to have higher incidences of broken tails than ground-dwelling species, perhaps because the tail is usually less important in locomotion in the first group. Many lizards possess conspicuously coloured tails and tail movements that seem likely to help distract attention from the head and body. Conspicuous tail colouring is more frequent and often better developed in young animals, which tend to be more vulnerable than adults, and in active species from open habitats where crypsis may not always be very effective. Conspicuous tails usually have contrasting light and dark areas in nocturnal forms but are often a single bright colour in diurnal ones, probably reflecting the visual capacities of their respective predators. The predominance of blue tails in day-active species may be because this colour is striking close to but not very arresting at a distance, so it may not attract predators from far away while still drawing their attention at close quarters.

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The basic anatomy of the lacertid hemipenis (intromittent organ) and methods for its investigation are described. In many members of the Lacertidae, the hemipenis has a structure quite unlike that of other squamate reptiles: the distal lobes of the retracted organ are complexly folded and there is a well-defined supporting structure of dense connective tissue, the armature. This incorporates blood sinuses and has an intramuscular portion embedded in the m. retractor penis magnus and two club-shaped bodies, the clavulae, that support the lobes in the erect organ. Unarmatured hemipenes occur in some lacertids and, like those of other squamates, possess sac-like lobes in the retracted state, but they are singular in having the lobes invested by the m. retractor penis magnus. It is argued that many of these apparently primitive hemipenes are in fact secondary derivatives of the armatured type. There is considerable inter-specific variation in hemipenial structure which is described systematically. In some cases this involves differences in size, asymmetry and simplification, which may arise as physical isolating mechanisms and is useful in distinguishing otherwise very similar species, particularly in the genus Mesalina (p. 1253). Other shared derived hemipenial features provide useful information about relationships between species and higher taxa and a summary of the hypotheses that they support is given (p. 1254).

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A key and check list is provided to the 96 species and six additional subspecies of lizards and two species of amphisbaenians known to occur in and around Arabia. Philochortus neumanni, Lacerta jayakari, Lacerta cyanura, Latastia longicaudata andersonii, Mesalina guttulata, Mesalina olivieri, Mesalina martini, Mesalina brevirostris, Mesalina ayunensis, Mesalina adramitana, Acanthodactylus orientalis, Acanthodactylus robustus, Acanthodactylus opheodurus, Acanthodactylus boskianus, Acanthodactylus felicis, Acanthodactylus yemenicus, Acanthodactylus masirae, Acanthodactylus opheodurus, Acanthodactylus gongrorhynchatus, Acanthodactylus haasi, Acanthodactylus schmidti, Acanthodactylus blanfordii, Acanthodactylus arabicus, Acanthodactylus grandis, Acanthodactylus tilburyi, Acanthodactylus scutellatus hardyi.

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The structure of copulatory organs is used very widely in systematics, both for differentiating species and for working out relationships. Differences between taxa may arise from a variety of sources, including non-homology, differences in other parts of the animal, direct selection on copulatory organs, development of physical isolating mechanisms and pleiotropic events. Physical isolating mechanisms seem likely to account for the abrupt differences, involving size, asymmetry and simplifications, that are useful in distinguishing very similar lacertid species. Although these differences usually seem to arise at the end of a speciation event they can simultaneously be the initiating mechanism in a second one. Copulatory organs appear to have high inherent stability, probably resulting from frequent location in strongly homoeostatic environments, single function, insensitivity to niche shift and inertia due to the need to conform to the genitalia of the opposite sex. This stability may be overridden at times by direct selection on the organs themselves or pleiotropic events. Such changes tend to be retained because efficiency in copulation depends not on any absolute genital architecture but on close conformity of the organs. It is the combination of relative stability and tangible input of varied change, which tends to be retained, that so often makes these structures good indicators of relationship.

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Arabia, including the arid lowland regions of Jordan, Syria, Iraq and southwest Iran, has approximately 128 species of terrestrial reptiles and about 7 of amphibians. Endemicity is high, 55% of species being largely or entirely confined to the area. Abrupt faunal discontinuities are present between Arabia and neighbouring regions, namely the Horn of Africa, the Sahara desert and the relatively mesic areas to the north. However, there must have been substantial interchange with these areas in the past. Within Arabia, the main Zoogeographie division is between the arid regions occupying most of the peninsula and much smaller, often more mesic areas of endemicity in the south. The former are mainly occupied by Saharo-Sindian taxa and have rather more affinities with the Sahara than to arid regions east of Arabia. Southern areas of endemicity include: 1. The southwestern coast, with affinities to the Horn of Africa and the inland deserts of Arabia. 2. The southwest and southern highlands which share a number of forms with northeast African relationships but differ significantly, the former having more, often endemic species with African affinities and a number with relatives in the Mediterranean and other northern mesic regions. The drier southern mountains have their own endemics, some of which have representatives in the öiddat al-HaräsIs area to the east. 3. The north Oman mountains also possess distinctive species and populations, some of which are related to forms in the less arid parts of the Iranian area. Finally there are a number of mesic forms distributed around the periphery of Arabia, and populations at oasis sites in the arid region which are probably relicts of forms more widespread in Quaternary pluvial phases.

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Kurze Vorstellung der drei Eidechsenarten Acanthodactylus felicis, A. opheodurus und Mesalina ayunensis aus der omanischen Provinz Dhofar.

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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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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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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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Taxonomic changes and new findings concerning the subfamily Eremiainae in Africa are summarized to update SZCZERBAK`s (1975) catalogue of the African Sand Lizards. Furthermore, a key to the species and subspecies of the genus Pedioplanis is provided.

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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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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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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.