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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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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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Significant contributions to the poorly known reptile fauna of northern Mozambique were made during a biodiversity survey of the Niassa Game Reserve (NGR), situated in northern Mozambique, bordering Tanzania. Of approximately 100 reptile species currently known from northern Mozambique, 57 species were recorded from the NGR. Important discoveries included: a new species of girdled lizard (Cordylus sp.) in rock cracks on the summit outcrops of Serra Mecula; the first national records of Melanoseps sp. and Lygodactylus angularis (both isolated populations are atypical and further studies are required to assess their taxonomic status); the first records for northern Mozambique for Chirindia swynnertoni, Lygodactylus chobiensis, Pachydactylus punctatus, Elasmodactylus tetensis, and Latastia johnstoni; the most northerly records of Pachydactylus punctatus, Agama kirkii, and Gerrhosaurus vallidus; an unusual population of Bitis arietans whose taxonomic status require further analysis; and a population of Cycloderma frenatum in the Lugenda River that fills a large gap in the species’ known distribution.

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The Port Elizabeth Museum collection holds nearly 500 reptile specimens from Zambia and adjacent southeastern Democratic Republic of the Congo. These are reviewed, and biological and distribution data on 5 chelonians, 27 lizards and 38 snake species from Zambia are presented. These include information on 2 chelonians, 11 lizards and 19 snake species recorded from the poorly-known northern lVwinilunga District, Northwestern Province. Among the important findings are: the second largest specimen of and second Zambian locality for the dwarf terrapin, Pelusios nanus, with details on H`e first documented data on reproduction and sperm retention; the close proximity, without intergradation, of Lygodactylus heeneni and L. angularis suppOlting elevation of the former to specific status; a range extension of about 345km and the most northerly record (Chingola) for the gecko Lygodactylus chobiensis; a north-westerly range extension of more than 300km (to Chingola) for the gecko Hemidactylus mabouia (both these records may be translocations); the third and fourth reco]`ds for Zambia, and the most southern to date, for the gecko Pachydactylus tuberculosus; the first detailed biological information on the rare skink, Mabuya ivensii, which was first collected from Zanbia during these collections; asynchronous reproduction in Sakeji populations of both Mabuya maculilabris and M. wahlbergii; a southern range extension to Shimabala for the rare skink Eumecia anchietae; a range extension for the skink Lygosoma afrum to Sampfya town; the first record of lchnotropis capensis in the Copperbelt, and a north-westerly range extension of mon: than 300km to Chingola; the absence of asynchronous reproductive cycling between lchnotropis capensis and I bivittata in July at Sakeji; support for the specific status of Limnophis bangewoliCi,lS based on differences in colouration of the supralabials and subcaudals; new record sizes for both sexes of Dipsadoboa shrevei shrevei; a new record size for female Psammophis brevirostris leopardinus; and probable sympatry between Naja annulifera and its sister species N. anchietae at Livingstone.

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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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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 checklist records the 99 species of lizards known at present from Kenya, and which are divided amongst eight families: Gekkonidae 33 species, Agamidae seven, Chamaeleonidae 17, Scincidae 22, Lacertidae 12, Cordylidae five, Varanidae two, Amphisbaenidae one. Brief data on the distribution of all species is given, with some localities, details of habitat and (in some cases) status of subspecies. Some taxonomic notes on certain problematic species/genera are included, plus a brief discussion of the zoogeography of Kenya`s lizards, and a gazetteer of localities.