Un biofacies à Trilobites Homalonotidae dans I'Ordovicien de la marge nord-gondwanienne: implications paléobiologiques et paléogéographiques

During the Llandeilo, the sandy lithological units which develop locally in the Armorican Massif, Spain and Morocco, are all characterized by similar trilobite associations in which endobenthic homalonotids. well adapted to shallow water and sandy substrate, are predominant. During the Llandeilo, on the northern Gondwanan margin, the wide geographical distribution of most of the trilobites, controlled by environmental factors, shows that the existence of a 'Proto-Tethys' ocean is unlikely. □ North Gondwana, Trilobita, Homalonotidae, Ordovician, Llandeilo. palaeoenvironment.     

Stratigraphie, paléoécologie et foraminifères du paléogène des Alpes Maritimes et des Alpes de Haute-Provence (Sud-Est de la France)

Paleogene sedimentation in the Alpes Maritimes and Alpes de Haute Provence regions is composed of one complete sedimentary sequence. This sequence begins with the continental Formation from Microcodium and continues with the Cerithium layers, the Calcaires Nummulitiques and the Marnes Bleues, which are overlaid by the turbidites of the Grès d’Annot Formation. Sedimentation starts in the Nummulites perforatus zone close to the base of ‘the Truncorotaloides rohri zone (P 14) and ends in the Cassigerinella chipolensis-Pseudohastigerina micra zone (P 18) and the NP21 zone in the upper part of the Grès d’Annot. More biomarkers were used in order to define a more detailed local biozonation (biozones AMP 1 to AMP 7). Four local zones were also defined by the last occurrence of Nummulites millecaput and N. perforatus-N. ptukhiani and then by the first appearance of N. retiatus (AMGF 1-4). The evolution of benthic foraminiferal assemblages shows an increase in bathymetry from the internal platform in the Cerithium layers to the calcareous platform with large foraminifers, then to the external platform and the deep offshore environment of the Marnes Bleues and Grès d’Annot. Low faunal diversity in the Grès d’Annot together with the predominance of agglutinated species indicates a poorly oxygenated, organic rich and turbidite environment. Seven steps (SD 1 to SD 7) in the Eocene marine transgression are shown from East to West by detailed local biozonation and sequence analysis. Grès d’Annot sedimentation is also diachronous, beginning within the Truncorotaloides rohri zone (P 14, AMP 1) in the East and ending within the Pararotalia opima opima zone (P 20, middle Rupelian) in the West (Barrême). Small foraminifer Paleogene fauna from the Alpes Maritimes and Alpes de Haute Provence was studied from 400 samples. It is composed of 378 species. Two new taxa are proposed: Fissurina niceana n. sp. and Globocassidulina alpina n. sp. The species from the Escarène and Gorbio neighborhood described by M. von Hantken (1884) were re-examined.     

Ostracodes de la Formation de Bhanness,Kimméridgien (Jurassique supérieur) du Liban central : taxonomie,paléoécologie et paléobiogéographie

A microfauna composed of 11 species of ostracodes belonging to 11 genera have been recovered from the Bhanness Formation of Kimmeridgian age, in Central Lebanon. Four species are new and are described herein: Ektyphocythere dahressawanensis nov. sp., Dicrorygma (Orthorygma) libanensis nov. sp., Citrella? elongata nov. sp. and Procytherura inflata nov. sp. From a palaeobiogeographical standpoint, this fauna characterizes the North Gondwana province which differs from the South Gondwana province, particularly by the presence of the genus Schuleridea and the absence of the genus Majungaella.     

Ostracodes limniques de la Formation d'Irbzer, Crétacé terminal du Moyen-Atlas, Maroc : taxonomie, biostratigraphie, paléoécologie, paléobiogéographie

An association of limnic ostracodes has been discovered in the upper part of the Irbzer Formation, of Maastrichtian age, in the Moroccan Middle-Atlas. A new species is described, Gomphocythere achloujensis nov. sp. Paracandona occitanica, which is very common in terminal Cretaceous non-marine deposits of southern Europe (France, Spain), is found for the first time on the south Tethyan margin.     

Le bassin permien de Guardia Pisano (Sud-Ouest de la Sardaigne, Italie) : palynostratigraphie, paléophytogéographie, corrélations et âge radiométrique des produits volcaniques associés

The Permian section outcropping at Guardia Pisano (Sulcis area, SW Sardinia), comprises two successions, separated by an unconformity. The lower succession is composed of grey-black sandy shales, rich in plant remains and in sporomorphs, deposited in a fluvial-lacustrine to palustrine environment; followed by layers of rhyolithic lavas and volcanoclastites with silicified plant trunks. Most of the analysed samples yielded a profusion of pollen and spores in a very good state of preservation. Three associations were distinguished. The first one comprises mostly radial and bilateral monosaccate pollen grains and very few spores. This association is characterized by the presence of pollen grains of the genera Crucisaccites, Luberisaccites, Gondwanopollis and Lueckisporites, together with very abundant Potonieisporites and subordinate Florinites. The second association comprises mostly pollen grains of the genus Potonieisporites, represented by many species, together with Limitisporites, Costapollenites, Vittatina and others. Spores mainly represented by azonate trilete and monolete types are more frequent than in the previous association. These first two palynological associations reflect assemblages of meso-xerophilous plants growing in dryer environments, belonging to tropical and subtropical phytogeographic biomas. The third association, mainly composed of Sphenophyte spores, is autochthonous and corresponds to a swampy hygrophilous flora settled after the filling up of the basin. The age inferred by means of sporomorphs is early Asselian which is in good agreement with the mean radiometric age of the volcanic rocks obtained by the ‘SHRIMP’ and the lead-zircon evaporation methods (297 ± 5 Ma). The upper succession, is composed of grey to red sandstones and thin pelites deposited on an alluvial plain under very hot and humid climate; its Permian, post-Asselian age cannot be better constrained because of the scarcity of the fossil content.     

Paléogéographie des chasseurs de l’Europe du Paléolithique supérieur : répartition et spécialisation des sites

During the Upper Paleolithic, Europe was occupied by human populations mainly living from hunting of big terrestrial mammals. A repartition of fauna and of archeological sites was done with a database: a repartition of Upper Paleolithic sites in central and western Europe. This study shows that the european space was structured following several factors; climate, environment, cynegetic behaviours… We observe a partition of Europe with a mediterranean area with mainly deer, and ibex and an atlantic area with reindeer. Equally, most of the occupations are localized in the “aquitano-cantabric horn” around the Gulf of Gascony. The occupation of Europe undergone a pulsation with a retreat of occupations toward the west and the south during the glacial maximum, then a colonization of North Europe during the Tardiglacial climatic amelioration.     

Les sciuridés des gisements karstiques du Miocène inférieur à moyen du sud de la France : nouvelles espèces, phylogénie, paléoenvironnement

We describe sciurids from Lower and Middle Miocene karstic sites located in the south of France. Four new taxa are recognized here: Atlantoxerus martini nov. sp., Atlantoxerus sp. 1, Freudenthalia cuencae nov. sp. and Aragoxerus nov. sp. The last two genera are recognized for the first time in the south of France. A comparison with the Iberian peninsula is carried out, it tackles the problems of diversity, phylogeny and settlement. Hypothesis concerning the predation of these terrestrial squirrels and paleoenvironment is proposed.     

L’ambre albo-cénomanien de la montagne de Lure (Alpes-de-Haute-Provence), outil stratigraphique et paléogéographique

Nodules of fossil resin or amber, first drifted and then deposited in the marine series with cephalopods, were discovered in several areas of High-Provence, in geological series of the Cretaceous system. These areas are located around the Mountain of Lure; amber nodules have been found in the upper Albian (Ongles, Revest-des-Brousses) and in the lower Cenomanian (Saint-Étienne-les-Orgues, Aubignosc and Salignac). These ambers have very homogeneous and characteristic FTIR spectra, making it possible to distinguish them not only from more recent ambers of the upper Cretaceous of Provence (Santonian), but also from tertiary ambers of the Baltic sea. These organic matters in marine environment, brought by the currents and deposited in shallow waters of the Ventoux-Lure area, are in agreement with close emerged grounds, which were set up by the Albo-Cenomanian tectonic movements.     

Corrélation des successions de l'Albien par les ammonites entre la Province Nord-Pacifique et les Provinces européenne et arctique du Domaine boréal : zonation, eustatisme et paléobiogéographie

The vertical distribution of Albian ammonites of the North Pacific Province is described on the basis of several sections located in Northern California. Nine Albian ammonite assemblages are identified, compared to the 4 previously described by Murphy in 1956. Owing to several gaps of observation possibly more assemblages could exist. In the North California Albian history, the first results show a succession of confinement periods - with numerous endemic faunas - followed by periods of open communications with other faunal provinces. As an example, the base of the Middle Albian is marked by exotic ammonites coming from the Tethyan realm (Oxytropidoceras, Lyelliceras) and from the Arctic Province of the Boreal realm (Gastroplites, Pseudopulchellia). These ammonites - except Oxytropidoceras - were not known in that area and are described relatively to their palaeobiogeographical interest. Although rare these migrant faunas give valuable elements to correlate these various provinces. Planktonic foraminifera confirm the existence of open sea communications during the uppermost Albian.With such faunal links, a comparison is proposed between the Albian ammonite zonation of Northern California and the standard and phyletic ones of Europe. This attempt suggests that the major connections between the three faunal provinces are established at second order peak transgressions in the Early and Middle Albian, and during the sea-level high of the Late Albian transgressive period. So, it seems that the vertical distribution of Albian non-endemic ammonites of North California and Europe is largely controlled by global eustatic events. Two palaeobiogeographic maps for Early and Middle Albian and one map for the late Late Albian show the migration outer of these exotic ammonites.     

Les Spatangus du Miocène et du Pliocène de l’Ouest de la France

Numerous fragments of spatangoid echinoids have been discovered in the Pliocene deposits of Challans, in Vendée (western France). In spite of the fragmentary data of the samples, a reconstitution of a complete test could be realized using the different fragments and their symetrization. The general shape of the test, and its architectural and ornemental characters allow establishing the presence of the genus Spatangus in western France during the end of Neogene. It allows to precise the biogeography of the genus Spatangus and of the morphological group S. (S.) purpureus on the Atlantic coast after the Messinian crisis. The Pliocene species is compared to the Miocene Spatangus (Phymapatagus) brittanus, abundant in Anjou, Brittany and Touraine. This older species was refered to the subgenus Phymapatagus according to the presumed lack of primary tubercles on its posterior interambulacrum. The discovery of well-preserved specimens, with primary tubercles on every parts of the test, in the Middle Miocene of Brittany allows to refute this subgeneric distinction and to refer the species brittanus to the subgenus Spatangus (Spatangus). The presence of this subgenus in western France is finally confirmed from Middle Miocene to Pliocene.     

Étude taphonomique, paléoécologique et archéozoologique des faunes de grands mammifères de la seconde moitié du Pléistocène inférieur de la grotte du Vallonnet (Roquebrune-Cap-Martin, Alpes-Maritimes, France)

Vallonnet cave (Alpes-Maritimes, France) provided archaic lithic tools together with a big amount of large mammals of the end of lower pleistocene. At the crossing of diverse ecological niches in time and space, three main levels and within them several smaller units were distinguished. The poorly mineralized bones witnessed a huge diagenetic fragmentation. The presence of the animals in the cave seems to be linked to the reasons of their death. The exhaustive and systematic observation of the bones, like the bears probably used to die inside the cave. Some other carnivores especially hyenas, used the cave as a nursery. Man also occupied the cave and had an activity mainly on large cervid bones and on some other species as well. The very progressive deposit gave a way for carnivores and porcupine to gnaw the bones on the ground before their burial. The succession of actions (man, carnivores and porcupine) on the same bones is characteristic on Vallonnet large mammals bones.     

Les conceptions religieuses et idéologiques des tribus de l’âge du bronze en Azerbaïdjan et leurs traditions

The primitive religious view of tribes in Azerbaijan Bronze Age was in close connection with nature. Fire rituals had taken the main place in ancient people’s belief.     

Les statues-menhirs du Rouergue et du Haut-Languedoc : la posture des jambes et la technique de représentation des effigies féminines et masculines

Wex (1993) observes through the statuary of great historical cultures how body language appears to reflect the evolution of the respective status of man and woman. On the other hand, Serres (1997) reports that the feminine statues-menhirs of his so called groupe rouergat are represented with legs spread out, while masculine statues show broad as well as narrow postures. We examined this observation more systematically and further applied to it the properly ethological reading grid of Wex as a contribution to the history of gender relationships. A preliminary quantitative analysis aimed to determine which attributes give certainty about the sexual identity of the statues-menhirs. Special attention is given to the figures who underwent a gender change.     

Interaction du photopériodisme et des effets de la zéatine, du saccharose et de ľeau dans la floraison du Chenopodium polyspermum

Interaction of photoperiodism and zeatin, sucrose and water effects on the flowering of Chenopodium polyspermum Root removal in Chenopodium polyspermum, a quatitative short-day plant, enhances flowering under non-inductive conditions. Presence of roots may be mimicked by zeatin applications on buds. Induction of flowering by short days may be counteracted by applications of zeatin, and appearance of flowers depends on the balance between number of inductive short days and zeatin quantity applied. Sucrose added in the culture medium or applied on buds acts as zeatin. Applications of water on buds may also delay flowering. These results show the plurifactorial regulation of the floral development of this plant. The relations between the non-specificity of the induction and the specificity of the morphogenetic response are discussed.     

Arkaïm-Sintachta : expérience de la mise en valeur des steppes eurasiatiques à l’Âge du Bronze

The “Earth of fortified settlement” is one of the last big discoveries of the end of the XXth century. Situated on the oriental slopes of the mounts of Ural, fortified settlement, date the Middle Bronze Age. These strengthened structures are particular in the archaeology of steppes. They were built according to geometrical plans, Cities in oval being the most ancient, the rectangular cities being the most recent. The most remarkable are together of strengthened structures appropriate for the culture of Sintachta-Arkaïm. This city distinguishes itself from the others by the unique integrity of the works of fortification and by the graves which are connected to these last ones. Situated on a prominence, Arkaim consists of two defensive walls, maybe of a third, the rampart and the ditch. The space between the defensive walls was occupied by the houses of shape trapezoidale and directed as beams to the center of the city. The center of the city, the rectangular shape, was not built and formed a place where foyers were found. Complex entrances were at the four corner of the city. The excavations of fortified settlement and graves allowed to have an idea on the level of development of the everyday life at the time of the Middle Bronze Age in transouraliennes plains.