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Results of 12 days fielwork on reptiles in Pendjari National Park (Benin).

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Data about West African non-avian reptiles still remain scarce and, in particular, bibliography provides little information about the herpetofauna in the WAP complex pro- tected areas (W Transfrontier Biosphere Reserve, Arly and Pendjari Parks). At the request of ECOPAS project and with CIRAD financing we undertook, from May 2006 to November 2007, an herpetologi- cal survey of the W Transfrontier Biosphere Reserve straddling three countries : Niger, Benin and Burkina Faso. This study allowed us to record 83 reptiles species, which represents a high biodiversity for an African savanna area ; moreover we discovered a new species of cobra of the Naja haje group during this study in the W Reserve. Biogeographic analysis shows that, besides five ubiquitous species, most of the reptile species of the area (70%) are typically Sudanese savanna ones ; however a 17 Sahe- lo-Saharan species group enters the northern part of the area, while three typically guinean species extend to the southern part of the reserve through forest galleries.

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A large number of reptiles from the Central African Republic (CAR) were collected during recent surveys conducted over six years (October 1990 to June 1996) and deposited at the Paris Natural History Museum (MNHN). This large collection of 4873 specimens comprises 86 terrapins and tortois- es, five crocodiles, 1814 lizards, 38 amphisbaenids and 2930 snakes, totalling 183 species from 78 local- ities within the CAR. A total of 62 taxa were recorded for the first time in the CAR, the occurrence of numerous others was confirmed, and the known distribution of several taxa is greatly extended. Based on this material and an additional six species known to occur in, or immediately adjacent to, the coun- try from other sources, we present a biogeographical analysis of the 189 species of reptiles in the CAR.

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We have used mitochondrial 12S rRNA, 16S rRNA and nuclear β-fibrinogen (intron 7) sequences to investigate the phylogenetic and phylogeographic relationships between Acanthodactylus erythrurus group species (except for A. boueti). The phylogenetic analyses of the Acanthodactylus genus did not cluster A. guineensis and A. savignyi with the remaining species of the group (A. blanci, A. lineomaculatus and A. erythrurus). Within the A. erythrurus group, the results of the mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) showed a complex phylogeny with geographic structure, but it was not congruent with the present taxonomy. Some taxonomic units, such as A. blanci, A. lineomaculatus, A. e. atlanticus and A. e. belli did not form monophyletic genetic units. The application of a molecular clock suggested that the uplift of the Atlas Mountains in the mid-late Miocene and the reopening of the Strait of Gibraltar could be major biogeographic events responsible for the genetic differentiation in the group. Additionally, diverse micro-evolutionary patterns due to the recent contraction/expansion phases of the habitats in North Africa associated with the high dispersal capabilities of these lizards could be related to the complex phylogenetic patterns observed.

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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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Climate has a large impact on diversity and evolution of the world’s biota. The Eocene–Oligocene transition from tropical climate to cooler, drier environments was accompanied by global species turnover. A large number of Old World lacertid lizard lineages have diversified after the Eocene–Oligocene boundary. One of the most speciose reptile genera in the arid Palearctic, Acanthodactylus, contains two sub-Saharan species with unresolved phylogenetic relationship and unknown climatic preferences. We here aim to understand how and when adaptation to arid conditions occurred in Acanthodactylus and when tropical habitats where entered. Using whole mitogenomes from fresh and archival DNA and published sequences we recovered a well-supported Acanthodactylus phylogeny and underpinned the timing of diversification with environmental niche analyses of the sub-Saharan species A. guineensis and A. boueti in comparison to all arid Acanthodactylus. We found that A. guineensis represents an old lineage that splits from a basal node in the Western clade, and A. boueti is a derived lineage and probably not its sister. Their long branches characterize them—and especially A. guineensis—as lineages that may have persisted for a long time without further diversification or have undergone multiple extinctions. Environmental niche models verified the occurrence of A. guineensis and A. boueti in hot humid environments different from the other 42 arid Acanthodactylus species. While A. guineensis probably remained in tropical habitat from periods prior to the Eocene–Oligocene boundary, A. boueti entered tropical environments independently at a later period. Our results provide an important baseline for studying adaptation and the transition from humid to arid environments in Lacertidae.

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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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Despite the recently considerably increased knowledge of the distribution range of Acanthodactylus guineensis, scalation characters of all available specimens (67 specimens) of this rare lacertid lizard reveal no geographically correlated variation. A. guineensis, ranging from Mali to Cameroon, has to be regarded as monotypic. A lectotype is designated for Eremias benuensis Monard, 1949, a synonym of A. guineensis.

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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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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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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.