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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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A complete catalogue is provided for the type specimens of lacertid lizards in the herpetological collection of the Zoological Museum, Berlin, as of December, 1993. The collection contains a total of 514 type specimens, representing 63 taxa, of which 42 are currently regarded as valid at the specific or subspecific level. Types representing an additional four taxa appear to have been lost from the collection. The collections are especially rich in African lacertid types and in historically significant specimens collected early in the Nineteenth Century by Pallas, Eversmann, and Hemprich & Ehrenberg. Also present are the type series of many subspecies of Podarcis lilfordi and P. pityusensis described by Eisentraut.

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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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This book shows a comprehensive picture of the reptiles, excluding snakes, living in Europe, North Africa, Middle and Near East and Central Asia. The bulk of the book is an annotated checklist and a distributional atlas of approx 500 species of lizards, crocodiles, turtles and terrapins, and amphisbaenians, living in the Western Palearctic. Information on distribution, subspecies, chorotype and main references are provided for each species, as well as 226 colour maps showing the global distribution of the species on a grid of one degree. For each species map the bibliographic and original sources (more than 850 sources are listed) are indicated. A further 83 maps show the distribution of all genera and main species groups of Palearctic reptiles. Beside the checklist and the atlas, in some additional chapters the following arguments are treated: Materials and methods; status of knowledge on the Palearctic fauna; composition of the Western Palearctic reptile fauna (including a statement on biodiversity and species richness); descriptive biogeography (including a discussion on the Palearctic region boundaries based on reptile distribution and the herpeto-geographic sectors of the Western Palearctic); conservation status. A list of more than 730 references quoted in the text and high quality colour plates including photos of the most of the supraspecific taxa living in the study area completes the book.

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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.