Western Maghreb Research Articles

Biogeographic and demographic history of the Mediterranean snakes Malpolon monspessulanus and Hemorrhois hippocrepis across the Strait of Gibraltar

BackgroundThe contribution of North Africa to the assembly of biodiversity within the Western Palaearctic is still poorly documented. Since the Miocene, multiple biotic exchanges occurred across the Strait of Gibraltar, underlying the high biogeographic affinity between the western European and African sides of the Mediterranean basin. We investigated the biogeographic and demographic dynamics of two large Mediterranean-adapted snakes across the Strait and assess their relevance to the origin and diversity patterns of current European and North African populations.ResultsWe inferred phylogeographic patterns and demographic history of M. monspessulanus and H. hippocrepis, based on range-wide multilocus data, combined with fossil data and species distribution modelling, under present and past bioclimatic envelopes. For both species we identified endemic lineages in the High Atlas Mountains (Morocco) and in eastern Iberia, suggesting their persistence in Europe during the Pleistocene. One lineage is shared between North Africa and southern Iberia and likely spread from the former to the latter during the sea-level low stand of the last glacial stage. During this period M. monspessulanus shows a sudden demographic expansion, associated with increased habitat suitability in North Africa. Lower habitat suitability is predicted for both species during interglacial stages, with suitable areas restricted to coastal and mountain ranges of Iberia and Morocco. Compiled fossil data for M. monspessulanus show a continuous fossil record in Iberia at least since the Pliocene and throughout the Pleistocene.ConclusionsThe previously proposed hypothesis of Pleistocene glacial extinction of both species in Europe is not supported based on genetic data, bioclimatic envelopes models, and the available fossil record. A model of range retraction to mountain refugia during arid periods and of glacial expansion (demographic and spatial) associated to an increase of Mediterranean habitats during glacial epochs emerges as a general pattern for mesic vertebrates in North Africa. Moreover, the phylogeographic pattern of H. hippocrepis conforms to a well-established biogeographic partition between western and eastern Maghreb.

Taxonomy of the North Moroccan and Iberian species of the subgenus Amblypteraca/ (Coleoptera: Tenebrionidae: Pimeliinae: Pimelia/).

The subgenus Amblypteraca Mas-Peinado, Buckley, Ruiz García-París, 2018 of Pimelia Fabricius, 1775, is restricted to the southern Iberian Peninsula and western Maghreb (northern and western Morocco). The distribution of Amblypteraca throughout the African-European edges overlaps largely with the geographic range of the subgenus Amblyptera, which is sister to the clade grouping subgenera Amblypteraca and Ecphoroma Solier, 1836. Delimiting species boundaries in the speciose genus Pimelia is often challenging, and the taxonomic status of some groups within the aforementioned subgenera is still a matter of debate. Here, we aim to stabilize some of the available names in Amblypteraca, and to correct some previous misidentifications. For that purpose, we discuss the composition and taxonomic structure within Amblypteraca by (i) assessing the phylogenetic congruence between mitochondrial and nuclear markers, and (ii) examining external morphological traits in 568 Amblypteraca specimens under the light of the phylogenetic hypotheses proposed here. Based on our results, Amblypteraca consists of three species: P. rotundipennis Kraatz, 1865, P. fairmairii Kraatz, 1865 and P. chrysomeloides Pallas, 1781. Both molecular and morphological data revealed four lineages within P. chrysomeloides: P. chrysomeloides chrysomeloides, distributed on both sides of the Strait of Gibraltar; P. chrysomeloides fornicata Herbst, 1799 from Portugal (Troia region); P. chrysomeloides bathyglypta Antoine, 1949, restricted to a narrow strip between Larache and Arbaoua (northern atlantic Moroccan coast), and P. chrysomeloides subris Koch, 1941 from Kenitra-La Mamora forest (Morocco). We designate a neotype of Tenebrio chrysomeloides Pallas, 1781 and propose the synonymy of P. chrysomeloides (Pallas, 1781) = P. obesa Solier, 1836 syn. n. Pimelia tristis Haag-Rutenberg, 1875, previously misidentified and included in Amblypteraca, is now transferred back to Amblyptera. Further studies with ad hoc sampling designs and analytical tools would be in need to delimit the exact geographic ranges of these taxa, and to analyse the patterns of diversity within and among species and subspecies.

Phytolith analyses from Khil and Kaf Taht el-Ghar (Western Maghreb): Plant use trajectories in a long-term perspective

In this paper we present the results of phytolith investigations at two archaeological sites in northwestern Morocco: Khil (Tangier) and Kaf Taht el-Ghar (Tétouan). The two sites located in Western Maghreb, one on the Atlantic and one on the Mediterranean coast, were investigated in the framework of the AGRIWESTMED project. Phytolith analysis complemented archaeobotanical, geoarchaeological and archaeological investigations to better identify plant use during the entire occupation sequence. At Khil 16 samples have been studied, coming from two profiles excavated in two different caves of the same system – grotte B and grotte C – that span a chronology comprised between the early Neolithic and the historic period. At Kaf Taht el-Ghar, 15 samples were analysed spanning from the Palaeolithic to the Historic period.Results show that at Khil plants are widely used from the very beginning of the Early Neolithic sequence. The surrounding vegetation was exploited and both C3 and C4 grasses were used, inside the cave. At the same time a wide array of other plants was utilised, such as palms and woody taxa. Phytolith analysis at the site of Kaf Taht el-Ghar indicates that crop processing was most probably not taking place on site. However, the predominance in the samples of C3 grasses morphologies agrees with the finding of previous macro botanical studies that identified cultivated wheat and barley in this cave deposits. A very interesting aspect of the phytolith assemblages of Kaf Taht el-Ghar is the widespread use of palm leaves and their gradual disappearance through time that coincides with an increase in the use of woody species.

Hidden species diversity of Corrosella Boeters, 1970 (Caenogastropoda: Truncatelloidea) in the Moroccan Atlas reveals the ancient biogeographic link between North Africa and Iberia

Despite the high species richness of freshwater gastropods in the western Mediterranean, the evolutionary patterns of the North African taxa are poorly understood. In a recent survey of spring habitats in the Atlas Mountains of Morocco (western Maghreb), we discovered ten snail populations anatomically resembling the genus Corrosella (family Hydrobiidae), which was supposedly endemic to the Iberian Peninsula and southern France. Through morphological and molecular investigations, we assessed the taxonomic status of these populations and their evolutionary origins. Molecular phylogenies based on three gene fragments (COI, 16S rRNA and 28S rRNA) from snails of the newly collected populations and 12 additional congeners distributed across the Iberian Peninsula and southern France clustered together the Moroccan populations within Corrosella in a well-supported clade comprising six putative species: two previously identified as Hydrobia marocana and Pseudamnicola pallaryi and four unknown lineages here described as species new to science. According to a molecular clock analysis calibrated with an external rate, the Moroccan clade originated ca. 7.6 million years ago (Mya) (11–4.5 Mya) and its divergence from the southern Iberia lineages likely occurred 8.4 Mya (12.5–5.5 Mya). This suggests that the biogeography of Corrosella in the western Maghreb has been shaped by old vicariance events likely associated with the Late Miocene-Pliocene geological setting of the region and their interplay with the isolation conditions of springs. Our findings considerably expand knowledge of the diversity and geographic range of Corrosella and provide new insight into faunal relationships between North Africa and Europe.

Revisiting the Epipalaeolithic-Neolithic Transition in the Extreme NW of Africa: The Latest Results of the Chronological Sequence of the Cave of Kaf Taht el-Ghar (Tétouan, Morocco)

This study focuses on the chronostratigraphic sequence of the Cave of Kaf Taht el-Ghar (Dar Ben Karrich, Tétouan, Morocco) excavated in 2012 in the framework of the AGRIWESTMED research project. The broad sequence reveals a series of occupations ranging from the Pleistocene (Moroccan Aterian) to recent historical times. Our research identifies a rich Early Neolithic phase (sixth millennium cal BC) containing the earliest pottery and domesticated animal and plant remains in the western Maghreb. However, this Early Neolithic level is not an immediate successor of the last traces of the Epipalaeolithic hunter-gatherer occupation, which started at the end of the Younger Dryas (10,900–9700 cal BC). An abandonment phase, spanning more than a millennium, separated them. This hiatus appears to originate from a cold climatic event that began in the late seventh millennium cal BC (ca. 6200 BC) and ended around the mid-sixth millennium cal BC.

Considerazioni sulla pirateria e sulla corsa musulmana e cristiana all'epoca della conquista portoghese di Ceuta (1415)

Dans les années qui précedent la conquête de Ceuta (1415) les nom­breux événements de piraterie et de course dans la Mediterranée occidenta­le et dans le Détroit de Gibilterre provoquaient une condition de grande difficulté pour les trafiques avec le Maghrib occidentale et l’Emirat de Grenade. Les vaisseaux aragonaises que commerciaient dans les ports maghrebins, surtout en or, sont particulièrement frappés par les assauts et les déprédements, les auteurs desquels étaient des autres marineries chré­tiennes. Lettres adressées au roi d' Aragon, Fernando I, dénoncent d'une façon très preoccupée, une telle action qui aurait pu porter aussi à la fin des mêmes trafics. En parallèle, autre genre de documentation fait penser que la piraterie musulmane n'avait pas eu, en cet endroit et en ce période, une égale inci­dence. Les ostilités portugaises contre “l’infidèle", (selon les chroniques de Zurara la "Crónica da tomada de Ceuta" et la "Crónica do Conde D. Pedro de Menezes "), plûtot que contre la piraterie musulmane semblent être adressées, d'une partie à la conquête territoriale de la ville maghrebine, et donc au controle de la navigation musulmane et chrétienne dans le Détroit, et d'autre partie à l'anéantissement des trafiques commerciaux des musul­manes avec des attaques constants et systémathiques de leurs navires.

DNA taxonomy of the potamid freshwater crabs from Northern Africa (Decapoda, Potamidae)

AbstractThe Mediterranean area, from southern Balkans to western Maghreb, is inhabited by the Potamon subgenus Euthelphusa, with three currently recognised species. The Maghrebian species P. (E.) algeriense is isolated from other Potamon species by the Mediterranean Sea and the Sahara Desert, and nearly no molecular data are currently available for this taxon. Present study investigated the mtDNA and nuDNA diversity in Potamon algeriense s.l. with the aims of exploring its molecular diversity pattern throughout its known distribution range, and testing the possible presence of cryptic taxa currently lumped under this binomen. The phylogenetic and DNA taxonomy analyses showed the presence of two well‐supported clades of species rank within P. algeriense s.l, with an eastern clade including the populations from Tunisia and Numidia, and a western, highly structured clade including the populations from central Algeria and Morocco. In agreement with a typical Maghrebian biogeographic pattern, the distribution of these two species shows a clear east–west divide, with a disjunction zone located in Kabylia, and a strong link between molecular diversity and segregation within different hydrographical basins is evident. The Maghreb thus proved to host an unexpectedly high genetic diversity of, and to constitute a biodiversity hot‐spot for, the Potamon subgenus Euthelphusa. In the light of the existence of two well‐characterised species currently lumped under P. algeriense s.l., and of their noteworthy molecular structuring, the status of Maghrebian Potamon populations should be re‐assessed for both the species present in the area, which are to be considered as independent management units.

Lophyra flexuosa (Fabricius, 1787) (Coleoptera: Cicindelidae) in desert countries: morphological variability in geographic aspect as potential beginning of speciation?

Lophyra flexuosa is one of only several eurytopic tiger beetles species known from Palearctic realm. Its geographical distribution shows several populations that are spread from the Iberian Peninsula and Morocco, across some regions of south-western Europe and northern Africa to Israel and Syria. The species is characterized by long phenological activity, wide altitudinal distribution, and occurs in the highest number of habitats among all Cicindelidae known from Maghreb region. In the present study the geographical variation in morphology and sexual dimorphism in north African populations of L. flexuosa was studied. In total 52 samples with over 700 specimens were collected including 20 samples in Morocco and 32 in Tunisia. To test the variation in morphometric traits measurements of eight body parameters were taken from all males (383) and females (352) including right mandible length, length of head, width of head, length of pronotum, maximum pronotum width, length of elytra, maximum elytra width, and total body length. We discovered significant sexual dimorphism expressed by larger body size of females and longer mandibles in males, what can be explained by different roles of particular sexes in courtship. Moreover, we recorded significant differences in body sizes between western and eastern Maghreb populations which can suggest genetic isolation between these populations. As the species is related to habitats placed close to water reservoirs, which in the desert countries are under significant human pressure (including climate change), we expect an reduction of habitats occupied by this taxon. Therefore, the geographic morphological variability that we observe today in the tiger beetle Lophyra flexuosa may lead to speciation and creation of separate species in the future.

Human occupation and environmental change in the western Maghreb during the Last Glacial Maximum (LGM) and the Late Glacial. New evidence from the Iberomaurusian site Ifri El Baroud (northeast Morocco)

With the onset of the Last Glacial Maximum (LGM), hunter-gatherers of the so-called Iberomaurusian techno-complex appeared in what is now the Mediterranean Maghreb. During a period of about seven thousand years, these groups left sandy occupation layers in a limited number of archaeological sites, while at the beginning of Greenland Interstadial (GI) 1, the sudden shift towards the deposition of shell-rich sediments and the increase in number of sites document clear changes in subsistence strategies as well as occupation density. It is highly likely that these shifts in human behaviour are related to paleoenvironmental changes in the area, which, so far, are poorly documented in geological and archaeological archives. Ifri El Baroud (Gunpowder Cave, northeast Morocco) contains a well-stratified archaeological sequence covering both phases of Iberomaurusian occupation separated by a sharp sedimentary change. In this paper, new chronological data and detailed investigations on site formation using sedimentology and micromorphology are presented. In addition, results of the analyses of fauna, pollen, macrobotanical remains, and phytoliths are included. This data contributes to a full-scale paleoenvironmental interpretation of the site’s archaeological deposits, highlighting the fluctuations of landscape conditions at the transition from the cold-arid Greenland Stadial (GS) 2.1 to the warmer and moister Greenland Interstadial 1.

The complete mitogenome of Helixpomatia and the basal phylogeny of Helicinae (Gastropoda, Stylommatophora, Helicidae).

A complete mitochondrial genome of the Roman snail Helixpomatia Linnaeus, 1758 has been sequenced. The length and gene order correspond to that of other available helicid mitogenomes. We used the mitogenome sequence to reappraise the relationships among the four presumed principal groups of the helicid subfamily Helicinae. The results support the idea that the subfamily is divided between two western Palaearctic diversification centres: Iberian Peninsula and western Maghreb in the west, and Anatolia, the Aegean and Caucasus in the east. One group, the tribe Helicini, diversified in the east and the remaining three currently recognised tribes in the west. However, the exact relationships among lineages of the non-Helicini tribes could not be resolved.

Diversification and speciation in tree frogs from the Maghreb (Hyla meridionalis sensu lato), with description of a new African endemic

Comparative molecular studies emphasized a new biogeographic paradigm for the terrestrial fauna of North Africa, one of the last uncharted ecoregions of the Western Palearctic: two independent east-west divisions across the Maghreb. Through a comprehensive phylogeography, we assessed how this model suits the genetic diversification documented for the tree frog Hyla meridionalis sensu lato. Analyses of mtDNA variation and thousands of nuclear loci confirmed the old split (low-Pliocene) between Tunisian and Algerian populations. These lineages meet but barely admix in the eastern Maghreb (Algerian-Tunisian border), a sign of putatively advanced reproductive isolation. In the western Maghreb, we report a Pleistocene divergence between Moroccan and Algerian populations. Tree frogs thus follow both predictions: a double east-west break that gave rise to two suture zones characteristic of North-African phylogeography. Moreover, some intraspecific mtDNA variation is not mirrored by the nuclear data, emphasizing that evolutionary units should always be designated by multilocus approaches. Last but not least, we describe the Tunisian lineage as a new species endemic to Africa.

The state-of-the-arts of the study on grid interconnection between Iberian Peninsula and West Maghreb region

With the change of energy structure in Europe and the trend of diversification of energy supply, the interconnection of the power grid in the Mediterranean region has gradually become a hotspot in European energy research. This paper introduces the power supply, load demand, power grid construction and the present situation of multinational interregional interconnection in the Iberian Peninsula of the Tour of Mediterranean in Europe (Portugal and Spain) and the Western Maghreb countries (Morocco and Algeria). And the driving force and influence factors of regional power grid interconnection are also analyzed. According to the MEDGRID project aimed at realizing the Mediterranean power grid interconnection, this paper presents the interconnection schemes of the Iberian Peninsula and the Western Maghreb. Furthermore, the subsequent technical problems need to be solved are also expounded.

Methods of Enquiry: Reconstructing Ancient Marine Resource Exploitation in the Western Maghreb

This paper describes a study that focuses on the western Maghreb’s transition into the Roman province of Mauretania Tingitana through marine resource exploitation: fishing, fish-salting and fresh marine resource consumption. To compensate for the issues inherent within the extant relevant datasets from previous excavations, this study applies an integrated methodology of investigation using a combination of archaeological and descriptive material: marine animal remains, fishing equipment, fish-salting sites, kilns and finds of salazon amphorae and written sources, tituli picti, pictorial representations and ethnography. As an example of the ensuing enquiry, the analysis of the case-study site of Lixus is summarised. When contextualised within a reconstructed littoral space, the combined data have the potential to provide a more complete and nuanced history regarding the use of past resources, ancient foodways, and human relations and interactions with the marine environment.

Underground cryptic speciation within the Maghreb: Multilocus phylogeography sheds light on the diversification of the checkerboard worm lizard Trogonophis wiegmanni

Biogeographic and evolutionary patterns in the North African portion of the Western Palaearctic are poorly known. A high fraction of undescribed diversity is expected in this region, especially in groups such as reptiles. Here we used mitochondrial (12S, 16S, cytb) and nuclear (pomc, rag2, cmos) markers and morphological data to investigate phyletic diversification and phylogeographical structure in the amphisbaenian Trogonophis wiegmanni endemic to the Maghreb. Phylogenetic and molecular dating analyses based on gene trees and species trees support three deeply divergent lineages of Pliocene origin, two in Morocco and one in central Algeria and Tunisia. Parapatry, reciprocal monophyly, high genetic divergence and limited morphological differentiation between them suggest that these lineages represent independent cryptic taxonomic units. Emerging lines of evidence from this study and from available literature on Maghreb taxa support (i) a major biogeographic break between western and eastern Maghreb and (ii) a role of the Atlas as a biogeographic divide within the western Maghreb (Morocco). The origin of these biogeographic units is probably associated with the evolutionary events prompted by the Late Miocene palaeogeographic setting and later by Plio-Pleistocene climatic changes and their interplay with prominent orographic barriers within North Africa.

Unravelling the drastic range retraction of an emblematic songbird of North Africa: potential threats to Afro-Palearctic migratory birds

Understanding how culture may influence biodiversity is fundamental to ensure effective conservation, especially when the practice is local but the implications are global. Despite that, little effort has been devoted to documenting cases of culturally-related biodiversity loss. Here, we investigate the cultural domestication of the European goldfinch (Carduelis carduelis) in western Maghreb (Morocco, Algeria and Tunisia) and the effects of long-term poaching of wild populations (1990–2016) on range distribution, socio-economic value, international trading and potential collateral damage on Afro-Palearctic migratory birds. On average, we found that the European goldfinch lost 56.7% of its distribution range in the region which led to the increase of its economic value and establishment of international trading network in western Maghreb. One goldfinch is currently worth nearly a third of the average monthly income in the region. There has been a major change in poaching method around 2010, where poachers started to use mist nets to capture the species. Nearly a third of the 16 bird species captured as by-catch of the European goldfinch poaching are migratory, of which one became regularly sold as cage-bird. These results suggest that Afro-Palearctic migratory birds could be under serious by-catch threat.

Winter Distribution of Passerine Richness in the Maghreb (North Africa): A Conservation Assessment

This paper studies the factors affecting passerine (Order Passeriformes) species richness in the Western Maghreb, a region at the southwestern border of the Palearctic reputed as a primary wintering ground for many common European birds. The effect of productivity, temperature, landscape structure and geographical location on bird richness was explored at 220 localities across Morocco. The models resulting from multivariate analyses supported the effects of productivity, temperature and landscape cover on bird richness, with higher numbers of species occurring in warm farmlands of the northwest. The most suitable areas for birds avoided the cold and arid expanses of the Atlas Mountains and the Sahara and overlapped with the most human-impacted sectors. Within these areas, we detected an interspersed distribution of sectors of high bird richness and low human incidence. These sectors can be used as priority targets for conservation programmes of common birds during the winter.

Biogeographical dynamics of the Spanish Marbled White Melanargia ines (Lepidoptera: Satyridae) in the Western Mediterranean: does the Atlanto-Mediterranean refuge exist?

Climatic changes can cause severe range shifts of biota over time. During climatically challenging periods, many organisms often persist in suitable refugia. One rather important refuge area of thermophilic species of the Palaearctic region includes the Iberian Peninsula and the Maghreb region, known as the ‘Atlanto-Mediterranean’ refuge. In order to study this postulated refugium, we computed species distribution models to reconstruct the past potential distribution of Melanargia ines (Hoffmannsegg, 1804) during the last glacial maximum. We also sampled individuals from populations of this butterfly species at its distribution margins (Iberia, and western and eastern Maghreb), and performed allozyme electrophoresis to assess the biogeographical patterns. The projected continuity of a conductive climate from Iberia to the eastern Maghreb, and the lack of genetic differentiation across the entire distribution range of M. ines, is in favour of the existence of one Atlanto-Mediterranean refugium for this species. A relatively constant climate over the Atlas Mountains over long periods of time, as predicted by species distribution models and observed genetic diversity patterns displaying an accumulation of intraspecific variability in this area, supports the idea of an important stronghold of M. ines in this mountain range, as has already been shown for several other species. The lower genetic diversity of the Iberian and Tunisian population might be the result of a rapid range expansion originating from the Atlas region or the survival of smaller relict populations in the eastern Maghreb (which is underpinned by geographically restricted climatically suitable retreats in this area, computed using species distribution models). In general, these findings highlight the importance of the Atlas massif as a refugium for thermophilic species on the Palaearctic scale. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104, 828–837. ADDITIONAL KEYWORDS: allozyme electrophoresis – climatic stability – climatic oscillations – differentiation centre – range shifts – refugia – species distribution modelling.

From Africa to Europe and back: refugia and range shifts cause high genetic differentiation in the Marbled White butterfly Melanargia galathea

BackgroundThe glacial-interglacial oscillations caused severe range modifications of biota. Thermophilic species became extinct in the North and survived in southern retreats, e.g. the Mediterranean Basin. These repeated extinction and (re)colonisation events led to long-term isolation and intermixing of populations and thus resulted in strong genetic imprints in many European species therefore being composed of several genetic lineages. To better understand these cycles of repeated expansion and retraction, we selected the Marbled White butterfly Melanargia galathea. Fourty-one populations scattered over Europe and the Maghreb and one population of the sibling taxon M. lachesis were analysed using allozyme electrophoresis.ResultsWe obtained seven distinct lineages applying neighbour joining and STRUCTURE analyses: (i) Morocco, (ii) Tunisia, (iii) Sicily, (iv) Italy and southern France, (v) eastern Balkans extending to Central Europe, (vi) western Balkans with western Carpathian Basin as well as (vii) south-western Alps. The hierarchy of these splits is well matching the chronology of glacial and interglacial cycles since the Günz ice age starting with an initial split between the galathea group in North Africa and the lachesis group in Iberia. These genetic structures were compared with past distribution patterns during the last glacial stage calculated with distribution models.ConclusionsBoth methods suggest climatically suitable areas in the Maghreb and the southern European peninsulas with distinct refugia during the last glacial period and underpin strong range expansions to the North during the Postglacial. However, the allozyme patterns reveal biogeographical structures not detected by distribution modelling as two distinct refugia in the Maghreb, two or more distinct refugia at the Balkans and a close link between the eastern Maghreb and Sicily. Furthermore, the genetically highly diverse western Maghreb might have acted as source or speciation centre of this taxon, while the eastern, genetically impoverished Maghreb population might result from a relatively recent recolonisation from Europe via Sicily.

New chronometric data from Ifri n’Ammar (Morocco) and the chronostratigraphy of the Middle Palaeolithic in the Western Maghreb

In addition to South Africa, the Northwestern corner of the African continent is providing a wealth of data for the understanding of the behaviour of early modern humans. In NW Africa, this modern behaviour is associated with a technocomplex called ‘Aterian’. However, its definition as well as chronological position is heavily debated. As a common notion, the ‘Aterian’ is placed as the (more or less) last technocomplex of the Middle Stone Age/Middle Palaeolithic. However, the stratigraphy of the Moroccan site of Ifri n’Ammar provides evidence that the ‘Aterian’ cannot serve as a chronostratigraphic entity because of its presence in a stratigraphical sequence before as well as after Middle Palaeolithic industries lacking tanged tools. These should supposedly all occur beneath any layer containing tanged lithic objects, which are, at present, the main criteria for assigning an assemblage to the ‘Aterian’. According to the sequence of Ifri n’Ammar, the relative chronostratigraphical position of tanged tools is therefore shown not to be a single unit. Thermoluminescence (TL) dating of heated artefacts from the main layers of Ifri n’Ammar provides a first chronostratigraphic backbone for the site and for the Maghreb. Layer ‘Upper OS’, which contains tanged items as well as personal ornaments is dated to 83.3 ± 5.6 ka ( n = 10), while the underlying ‘Lower OS’, which is lacking tanged pieces, is dated to 130.0 ± 7.8 ka ( n = 9). The following layer (Upper OI), which again contains tanged items, and thus provides the earliest appearance of the technique of tanging is dated to 145 ± 9 ka. The base of the sequence is formed by a Middle Palaeolithic layer (Lower OI) again lacking tanged objects and dated to 171 ± 12 ka by TL on heated lithic artefacts. These data significantly push back in time the earliest occurrence of tanged tools and the sequence calls for a complete revision of the Maghreb chronostratigraphy.

Complex patterns of genetic diversity within Lacerta (Teira) perspicillata: Preliminary evidence from 12S rRNA sequence data

Lacerta (Teira) perspicillata (Dumeril and Bibron, 1839) is a small montane rockdwelling lizard, occurring in the western Maghreb (Morocco and Northwest Algeria) and in Menorca, where it has probably been introduced anthropogenically (Mayol, 1997). IntraspeciŽ c morphological variation is considerable. Some authors accept the existence of three subspecies, L. p. perspicillata, L. p. pellegrini and L. p. chabanaudi (Bons, 1968) but others consider them only morphotypes (Mayol, 1997). Although its phylogenetic relationships have been highly debated, mitochondrial sequence data suggest it is sister taxon to the Madeiran lizard Lacerta (Teira) dugesii (Harris et al., 1998; Oliverio et al., 2000). To investigate genetic diversity within L. perspicillata we sequenced part of the 12S rRNA gene from individuals from several populations including all three forms, and compared this to subspeciŽ c status.