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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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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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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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The evolutionary diversification of many terrestrial vertebrate groups is strongly linked to climatic events in the Cenozoic, the period from 65 Million years ago to today when modern animals first appeared. I investigated the effects of Cenozoic climate change on the taxonomic and morphological diversification of the Old World lizard family Lacertidae, with particular emphasis on the African radiation. African lacertids exhibit an unusual pattern of diversification, in which their highest species richness occurs in deserts north and south of the equator, despite being spread throughout the continent. This disparity is particularly surprising given that desert lacertids are thought to be evolutionarily younger than their mesic-dwelling relatives, suggesting increased diversification rates in arid habitats. To identify the evolutionary factors underlying this pattern, I use a combination of phylogenetic, morphological and ecological techniques. In Chapter 1, I apply Bayesian methods and fossil-based calibrations to molecular sequence data to construct a time-calibrated phylogeny for Lacertidae. I estimate that the family arose in the early Cenozoic, with the majority of their African radiation occurring in the Eocene and Oligocene. In Chapter 2, I describe changes in lacertid body shape across biomes and substrates, and find widespread morphological convergence in similar habitat types. I suggest that in addition to foraging demands, fluctuating and extreme climatic conditions, largely driven by precipitation and temperature, contribute to morphological convergence across independent arid-dwelling clades. Finally, I test if ancestral transitions in ecology, morphology, and rates of diversification temporally coincide with paleoclimatic events in the Cenozoic. I use High Resolution X-ray Computed Tomography to characterize changes in the skull related to life in arid habitats, and apply maximum likelihood methods to test if the origins of those traits temporally coincide with significant shifts in habitat, diversification rates and climatic changes. My results show that African lacertids experienced three major peaks in diversification, accompanied by the evolution of suites of arid-adapted morphological traits. These changes coincide with climatic shifts in Africa, including the transition from closed forests to open grasslands and savanna in the late Oligocene, prior to the peak temperatures of the mid-Miocene Climatic Optimum, and following the formation of the Benguela current leading to hyper-aridity in southern Africa. I conclude that deserts are important centers for reptile evolution, but that expected changes in climate due to global warming may outpace the ability of arid-dwelling species to adapt and persist in the future.

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Most herpetological research in Eritrea was conducted during the period 1827–1930 and was almost exclusively the preserve of Italian enthusiasts, who concentrated their efforts within an 80 km radius of Asmara. Virtually no field work has been undertaken on the Eritrean mainland in the past 65 years and a great deal still remains to be learned about the composition, distribution and status of the herpetofauna. The 109 species provisionally listed in the present work (Anura 19, Testudines 9, Crocodylia 1, Sauria 45, Serpentes 35) are predominantly savanna (37.5%) and deserticolous (33.1%) forms and the Eritrean highlands are impoverished by aridity. Of eight taxa which extend into this region from the Ethiopian Plateau, only three appear to be genuinely montane and the ability of the remainder to colonise lowland sites elsewhere in their ranges is taken as evidence of their resistance to drought conditions. Rhinotyphlops erythraeus (Scortecci 1928), which is known only from the type locality at an altitude of 2200 m, might conceivably be an Eritrean montane endemic, but the two nominally endemic anurans have no evident associations with high elevations and may therefore extend into neighbouring territories. The taxonomic status of Phrynobatrachus tellinii Peracca 1904 is very uncertain, but it has been possible to reach more definite conclusions about Rana cornii Scortecci 1929 and R. demarchii Scortecci 1929 following examination of the single surviving syntype of each species, recently rediscovered in London. The evidence from these specimens is that R. cornii is a junior synonym of Ptychadena schubotzi (Sternfeld 1917), while the name demarchii seems to represent a valid species which is most appropriately retained in the genus Rana (sensu DUBOIS 1992), at least until its relationships can be more satisfactorily determined on the basis of fresh material.

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This review lists Agama smithii Boulenger 1896 as a synonym of Agama agama (Linnaeus 1758), Agama trachypleura Peters 1982 as a synonym of Acanthocercus phillipsii (Boulenger 1895) and describes for the first time Acanthocercus guentherpetersi n. sp. Without more convincing evidence, Chamaeleon ruspolii Boettger 1893 cannot be accepted as specifically distinct from Chamaeleo dilepis Leach 1819, nor Chamaeleo calcaricarens Böhme 1985 from C. africanus Laurenti 1768. Consequently, 101 species of lizard are currently recognised in Ethiopia, of which some 40% appear to be denizens of the Somali-arid zone. This significant proportion is attributable in part to the importance of the Horn of Africa as a centre for reptilian diversification and endemicity, in part to the fact that this lowland fauna was rather extensively sampled during the 1930s, but also to the conspicuous neglect of lizards in other regions of the country. Mountain and forested habitats are widespread in Ethiopia, so it seems extraordinary to record only five saurian species which are believed to be endemic in such environments. The inference that there are many more still to be discovered has important implications for conservation, because montane forest is known to be among the most threatened of Ethiopian biomes and there is clearly an urgent need for its herpetofauna to be more thoroughly researched and documented.

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Aim To map and assess the richness patterns of reptiles (and included groups: amphisbaenians, crocodiles, lizards, snakes and turtles) in Africa, quantify the overlap in species richness of reptiles (and included groups) with the other terrestrial vertebrate classes, investigate the environmental correlates underlying these patterns, and evaluate the role of range size on richness patterns. Location Africa. Methods We assembled a data set of distributions of all African reptile species. We tested the spatial congruence of reptile richness with that of amphibians, birds and mammals. We further tested the relative importance of temperature, precipitation, elevation range and net primary productivity for species richness over two spatial scales (ecoregions and 1° grids). We arranged reptile and vertebrate groups into range-size quartiles in order to evaluate the role of range size in producing richness patterns. Results Reptile, amphibian, bird and mammal richness are largely congruent (r = 0.79–0.86) and respond similarly to environmental variables (mainly productivity and precipitation). Ecoregion size accounts for more variation in the richness of reptiles than in that of other groups. Lizard distributions are distinct with several areas of high species richness where other vertebrate groups (including snakes) are species-poor, especially in arid ecoregions. Habitat heterogeneity is the best predictor of narrow-ranging species, but remains relatively important in explaining lizard richness even for species with large range sizes. Main conclusions Reptile richness varies with similar environmental variables as the other vertebrates in Africa, reflecting the disproportionate influence of snakes on reptile richness, a result of their large ranges. Richness gradients of narrow-ranged vertebrates differ from those of widespread taxa, which may demonstrate different centres of endemism for reptile subclades in Africa. Lizard richness varies mostly with habitat heterogeneity independent of range size, which suggests that the difference in response of lizards is due to their ecological characteristics. These results, over two spatial scales and multiple range-size quartiles, allow us to reliably interpret the influence of environmental variables on patterns of reptile richness and congruency.

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The family Lacertidae encompasses more than 250 species distributed in the Palearctis, Ethiopis and Orientalis. Lacertids have been subjected in the past to several morphological and molecular studies to establish their phylogeny. However, the problems of convergent adaptation in morphology and of excessively variable molecular markers have hampered the establishment of well supported deeper phylogenetic relationships. Particularly the adaptations to xeric environments have often been used to establish a scenario for the origin and radiation of major lineages within lacertids. Here we present a molecular phylogenetic study based on two nuclear marker genes and representatives of 37 lacertid genera and distinct species groups (as in the case of the collective genus Lacerta). Roughly 1600 bp of the nuclear rag1 and c-mos genes were sequenced and analyzed. While the results provide good support to the hitherto suggested main subfamilies of Gallotiinae (Gallotia and Psammodromus), Eremiainae and Lacertinae [Harris, D.J., Arnold, E.N., Thomas, R.H., 1998. Relationships of lacertid lizards (Reptilia: Lacertidae) estimated from mitochondrial DNA sequences and morphology. Proc. R. Soc. Lond. B 265, 1939–1948], they also suggest unexpected relationships. In particular, the oriental genus Takydromus, previously considered the sister-group to the three subfamilies, is nested within Lacertinae. Moreover, the genera within the Eremiainae are further divided into two groups, roughly corresponding to their respective geographical distributions in the Ethiopian and the Saharo-Eurasian ranges. The results support an independent origin of adaptations to xeric conditions in different subfamilies. The relationships within the subfamily Lacertinae could not be resolved with the markers used. The species groups of the collective genus Lacerta show a bush-like topology in the inferred Bayesian tree, suggesting rapid radiation. The composition of the subfamilies Eremiainae and Lacertinae as well as their phylogeography are discussed.

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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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Latastia taylori spec. nov. (fig. 4) Latastia boscai (part) Parker, 1932, Proc. Zool. Soc. London, p. 355 (specs, e-m). Holotype a male, number 1931.7.20.337, in the British Museum, from the Buran Valley, 2500 ft. (10°20`N x 49°E); collected by Capt. R. H. R. Taylor, 17.X.1929. Head flat, depressed, once and three quarters as long as broad, its depth a little less than the distance between the tip of the snout and the anterior corner of the eye, and its length contained 4.25 times in the length from snout to vent. Nostril pierced between four shields; upper nasals forming a suture half the length of the fronto-nasal which is a little broader than long and broader than the internarial space; prefrontals forming a median suture shorter than that between the nasals; frontal not grooved, a little longer than its distance from the rostral, once and two thirds as long as broad; interparietal not quite twice as long as broad, in contact with an occipital half its length; 4 supraoculars, the first divided into two, second and third large and subequal, fourth very small; a row of granules separating the supra- oculars from the 5 supraciliaries. Lower eyelid scaly, translucent. Rostral not entering the nostril ; two superposed post-nasals, the lower in contact with the first and second labials ; anterior loreal half as long as the second; five or six labials anterior to the subocular, which is much narrowed on the lip and separated by two scales from the pos- terior loreal ; lateral edge of the parietal bordered by 3 elongate, narrow scales, of which the anterior is much the longest; anterior margin of the ear bordered by 3 or 4 scales of which the uppermost is the largest. Four pairs of chin-shields, the first 3 in contact and the last the largest; 31 gular scales between the chin-shields and the collar which has about nine scales on its edge, the median very large and the laterals grading into the granules of the neck. Dorsal scales oval, or subhexagonal, flat and smooth, in 39 series across the middle of the body and in 105 series between the occipital and the base of the tail (vertically over the vent) ; twenty-two in a transverse series between the hind limbs. Ven- trals in six longitudinal series, with straight posterior borders, the two median series much narrower than the others; no group of small pec- torals; twenty-five transverse series of ventrals; one very large preanal bordering the vent, preceded by another, but much smaller, shield. A series of enlarged plates beneath the fore-arm; upper tibial scales small, imbricate, keeled; ten or eleven femoral pores on each side; sub- digital lamellae strongly bicarinate 26 beneath the fourth toe. Caudal scales in equal whorls, oblique and strongly keeled above, smooth be- neath. Tip of the fourth toe reaching to midway between the arm and the ear. Pale reddish brown above and on the tail, faintly marbled with grey anteriorly and on the head; flanks anteriorly and side of the neck with very irregular brown and greyish-white vertical marblings. Lower sur- faces uniform white. Length from snout to vent 43 mm. Fore-limb 13 mm. Hind-limb 26 mm. Tail (regenerated in part) 87 mm. The following specimens are paratypes of this species: 1931.7.20.339 9 2000 ft. 10°15`N x 49°E 13.1.1930 1931.7.20.338 9 20 ft. 11°14`N x 49°E 3.XII.1929 1931.7.20.340-342 3 & & 2000 ft. 9°40`N x 49°E [Ex. Field Mus.j 8.II.1930 19317.20.335-336 d 9 3100-3300 ft. 10°13`N x 48°46`E 8.1.1930 This series shows the following variations from the holotype: The head may be once and two thirds as long as broad, and its depth equal to the distance from the snout to the eye; supraciliaries 5 to 7; one or two scales between the posterior loreal and the subocular; 5 or 6 labials anterior to the subocular; dorsals in 36 to 41 series across the middle of the body; ventrals in 23 to 26 transverse series; gular scales 28 to 32; plates in the collar 5 to 7; femoral pores 9 to 12; subdigital lamellae beneath the fourth toes 24 to 27. The fourth toe extends to some point between the shoulder and the middle of the neck. The colour is usually olive, almost uniform, but with traces of lighter marblings anteriorly and on the sides of the neck and anterior part of the flanks, the latter having a tendency towards the formation of verti- cal bars. The subcaudal scales are smooth proximally, but keeled dis- tally and an unregenerated tail is a little more than twice as long as the distance from snout to vent. These specimens were originally believed to be all immature, but a female of 42 mm. from snout to vent is pregnant and the species ap- pears to be consistently smaller than boscai. It is closely allied to the latter but may be distinguished by its broader, natter dorsal scales, the absence of a frontal groove and different colour; it appears to be restricted to the north-eastern districts of Somaliland from the Sol Haud to the coast, an area close to that in which the strongly striped L. boscai burii also occurs (fig. 4).

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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.