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Algeria is a case study of biodiversity ignorance. To date, there are neither complete inventories for any taxa nor atlas across the country! Yet, Algeria is of great importance for global biodiversity. The coastal area of Algeria is part of the global biodiversity hostpot which is the Mediterranean perimeter and has several regional red spots of biodiversity. Moreover, the Saharan part encompasses a diversity of endemic organisms adapted to the strong conditions of drought. The Algerian authorities are deploying an ambitious project for conservation aiming to reach 50% of the country`s surface as protected areas! However, the location of these protected areas and their management don’t obey to a scientific evidence based, but are rather based on experts opinion. The main aim of this thesis is the study of the biodiversity ignorance distribution in Algeria by focusing on the `Linnean, Wallacean, and Darwinian Shortfalls` and to contribute to reduce them. The first chapter aims at reducing the Linnean Shortfall by proposing 1) a first checklist of reptiles and amphibians of Algeria which is the result of an accurate review of scientific publications on these taxa in North Africa. 2) a first pre-assessment of the conservation status of reptiles and amphibians of Algeria for the production of the first national red list. The second part of this manuscript deals with the ignorance of the geographical distribution of species. The purpose of this part is to map the ignorance which is defined as the difference between the expected specific richness diversity and the observed specific richness. The predicted species richness was modelled with two approaches: 1 ecological niche modelling with the maximum entropy method (MaxEnt) to predict the suitable habitats for each species and then add the different binary layers of species presence to calculate the specific richness. 2) Minimum convex polygon method was used to create range maps of each species and were auditioned to obtain predicted species richness. Both approaches have shown the same trend at a national scale: the concentration of the richest areas along the Saharan Atlas and the High Plateaus which are the transition zone between the Sahara and the Mediterranean part of Algeria. The opposition of the Saharan with a low species richness and the northern part with a higher species richness. Finally, the Saharan massifs of the Hoggar and Tassili form a very distinct zone with a much greater wealth compared to the rest of the Sahara. In terms of gaps, in the northern part, Kabylie, El Kala National Park and the Oran region are fairly well surveyed. In the Sahara, only a few points are clearly well prospected as Biskra, Bechar and some areas of the Hoggar and Tassili. The third part deals with the distribution of genetic llineages in the Maghreb. The aim of this section is to locate the phylogeographic breaks between the divergent eastern and western populations of the Maghreb and to try to understand the mechanisms that led to this pattern of genetic diversity. To answer these questions, I carried out a comparative phylogeography on 11 species of reptiles and amphibians with continuous and wide distribution in the Maghreb. Two suture zones have been identified: one zone on the border of Algeria and Morocco, the other in Kabylia west of the Soummam valley. The divergences between the eastern clades and the western clades occurred between the pre-Messinian periods up to the pliopleistocene boundary and were maintained in climatic refugia in the East and West of the Maghreb.

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The taxonomy of the fringe-toed lizards of the Acanthodactylus scutellatus group has long been unstable and no consensus exists on the systematic status of its various forms. A multivariate analysis of morphological characters, performed on over 1000 specimens from most of the African range of this group, allowed us to clarify the specific allocation of most of the Saharan populations included in this species group. Based on comparisons of morphology between allopatric and sympatric populations of this complex, we propose the recognition of six biological species. Our results confirm the specific status of Acanthodactylus aureus , A. dumerili , A. scutellatus, A. longipes and the recently described A. taghitensis . In addition, we re-validate A. senegalensis (occurring from Mauritania and Mali south to Senegal), which has been treated as a synonym of A. dumerili by previous authors. Acanthodactylus longipes is reported for the first time from coastal Mauritania, and A. taghitensis (previously known only from a very small region in Algeria) is reported from continental Mauritania. The systematic section of this paper includes a full list of examined material, diagnosis and known distribution of each species, in addition to some information on geographical variation and ecology. A key for specific identification is provided as an appendix.

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A new Fringe-toed Lizard of the scutellatus group found in Algeria, in the Beni Abbès area, is described under the name of Acanthodactylus taghitensis, from Taghit, type locality. This species is especially characterized by the size difference between dorsal and lateral scales, by the possession of four supralabials in front of the subocular and by an original colour pattern.

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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 is the first comprehensive review of the reptiles of Mauritania. It includes distributional information and comments. Mauritania harbors 86 species of reptiles belonging to 21 families. Among these families, Colubridae and Lacertidae are the most diverse, with 14 and 13 species respectively. Other families, such as Agamidae, Gekkonidae, Scincidae or Viperidae are also well represented. Among the 80 continental species, 47.5% are Saharan, 33.8% Afrotropical, 16.2% Sahelian and 2.5% Mediterranean. The marine turtles form another important group, with six species. Eight species are excluded from the country list because of old identification errors, there is not enough evidence of their presence or due to changes in political borders. Among the species expected to occur in Mauritania, at least nine may occur in Saharan environments, 13 in the Sahel savannah and two may have been introduced.

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Algeria is situated at the crossroads between Europe and Africa. The northern part of the country is listed as an area of high biodiversity. Currently, the ecosystems (rivers, lakes, deserts, forests etc.) and the species are under more pressure than ever. The impact of humans is significant and many factors constitute a strong threat to this fauna, especially reptiles, which are the most vulnerable because of their low mobility. Thus, pollution, the drying up of wetlands and their conversion to agriculture have clearly affected the existence of many species. The herpetofauna of Algeria is one of the most diversified in the Mediterranean Basin, consisting of 104 species of which 16.98% are endemic. We suppose that the present list of reptilian fauna provided in this paper is not exhaustive and it is expected to include more species given the lack of research on reptiles in Algeria and its large area. Our dataset contains information on reptile occurrences in Algeria. The dataset is based on original research by the staff of the Laboratory of Environmental Sciences and Agroecology of Chadli Bendjedid University in Algeria. The conservation status of all recorded species is given.

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Evaluating flagship species and their potential for biological preservation and ecotourism development is a key issue for many audiences within the conservation and social fields. Despite several methods available to identify flagships, their application is often constrained in remote, poorly studied regions. Developments are needed in statistical and spatially-explicit approaches to assess species` traits influencing flagship appealing, to identify flagship fleets, and to map the location of flagship hotspots. Here, we developed a new method to identify flagship species in regions with knowledge gaps, using a two-stage statistical approach (ordination and clus- tering algorithms) to assess variable`s contribution to appealing and to group species sharing similar char- acteristics into flagship fleets. We then mapped areas concentrating the highest richness of flagships. Unique morphologies and behaviours, conservation status, endemicity, body size and weight, and feeding habits were the traits contributing the most to the flagship appealing. Nine flagship fleets were identified, from which two were the most suitable for conservation marketing and ecotourism promotion campaigns in Sahara-Sahel: Fleet A comprising 36 large-bodied species (18 mammals, 18 reptiles) and Fleet B including 70 small-bodied species (10 birds, six mammals, 54 reptiles). A total of 19 and 16 hotspots were identified for large-bodied and small-bodied flagships, respectively. The methodology was suitable to identify flagship species for conservation marketing and for developing ecotourism operations in the Sahara-Sahel, to independently assess which species` traits are re- levant for flagship appealing, and to organise fleets for multispecies-based marketing campaigns. The framework is scalable and replicable worldwide.

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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.

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Aim: Hyper-arid sandy and rocky fields rank among the least biologically diverse habitats of the desert biome, yet knowledge of local biodiversity patterns is also ex tremely poor. In the Sahara Desert, palaeoclimate oscillations affected the extent of hyper-arid habitats, but it is unclear how these dynamics determined the evolution and distribution of local specialists. Herein, we assessed cryptic diversity, diversification patterns and spatial connectivity within a Sahara-widespread group of dryland adapted lizards. Location: Sahara-Sahel ecoregions. Taxon: Acanthodactylus scutellatus species group. Methods: Inter- and intraspecific phylogenetic structure, divergence times, spatial genetic patterns and cryptic diversity were assessed using nuclear and mitochondrial loci. The effects of topography and land cover on phylogeographic structure and diversity were tested with generalized linear models. Interspecific hybridization was evaluated using 11 microsatellites across the group`s major sympatry zone, predicted based on ecological niche models. Results: Species of Acanthodactylus scutellatus group exhibit Late Miocene origins, followed by extensive intraspecific divergence throughout the Pliocene. The northern Sahara worked as a major diversification hotspot, harbouring a patchwork of small ranged, divergent lineages. These lineages are parapatric or sympatric and present concordant nuclear and mitochondrial differentiation, suggesting species status. Genetic connectivity increases in southern latitudes, with wide-ranging lineages spanning from the Red Sea to the Atlantic coast. Within these potential corridors, mountain outskirts and sand fields in the Sahara interior seemingly acted as origins for recent population expansions. Genetic diversity and connectivity are favoured by terrain roughness and soft-sand cover respectively. Three species inhabit the Atlantic Sahara sympatry zone without evidence of gene flow. Main conclusions: Overlooked species-level diversity within a major specialist group of Sahara drylands exposes the recurrent knowledge shortfalls present in hyper-arid desert environments. Humidity and sandy habitat shifts triggered potential successions of population isolation and re-connectivity, which favoured cladogenesis in northern desert regions and population expansions across southern east–west corridors.