Ostracodes du bathonien moyen et supérieur des grands-causses,sud de la France. Associations et paléoenvironnements

This work describes new species of ostracodes collected in the Middle and Upper Bathonian outcrops of the Grands-Causses, Southern France: Kirtonella vignesensis n. sp., Marslatourella bathonica n. sp., Micropneumatocythere montmejeaneansis n. sp., Praeschuleridea alzonensis n. sp., and illustrates the predominating species in the assemblages: Limnocythere larzacensis, Theriosynoecum aveyronensis et Fastigatocythere juglandiformis.Ostracode assemblages are characteristic of lacustrine to polyhaline and inner marine environments, and they vary according to changes in salinity, oxygen and trophic level.     

Les ostracodes et foraminifères associés des dépôts de l’Éocène moyen et supérieur de la coupe de Jebel Serj (Tunisie centrale). Intérêt biostratigraphique,paléoécologique et paléobiogéographique

The ostracod fauna collected from the Cherahil formation that crops out at the Jebel Serj section (central Tunisia) contains 24 species belonging to 12 genera. These ostracods are associated with 9 genera of benthic Foraminifera (including 4 Nummulites species) and 7 genera of planktonic Foraminifera. The biostratigraphic study of ostracod assemblages results to the recognition of 6 biozones which are correlated with Lutetian-Priabonian. The Shannon Weaver, Margalef and equitability indices point to internal platform netritic conditions, with minor fluctuations in depth and oxygenation. The palaeobiogeographic distribution of ostracod species found in the study area of Central of Tunisia establishes a good connexion with the basins developed in Northern Africa (Tunisia, Algeria, Libya and Mauritania) and the Middle East (Egypt and Jordan).     

Comparaison de l'état de conservation des phases minérales et organiques d'os fossiles. Implications pour les reconstitutions paléoenvironnementales et phylétiques

Bones have been collected from different geological sites, the sediment and the age of which being different. Comparizon between the mineral and organic phases shows the very fast alteration of the organic matrix in recent bones. Fossil bones show a loss in the organic matrices. Moreover, insoluble and soluble organic matrix alterations differ in a single bone. Implications of the diagenesis in palaeoenvironmental reconstruction and phylogeny are evoked.     

Étude biostratigraphique et paléobotanique des gisements de calcaire blanc callovien au nord de poitiers

The white limestone represents a thick facies in the callovian stage of the threshold of Poitou. It makes the object of a detailed stratigraphical study which leads to its fauna and flora in the principal fossiliferous localities. The vertical range of Ammonites, layer by layer, leads to a chronostratigraphical subdivision in zones, subzones and shows up an important sedimentation break in the Upper Callovian in the axial region of the threshold of Poitou. Besides, a systematic study of plant remains gives original elements on the callovian flora in the West of France. These observations are completed by considerations of tectonic, sedimentary, paleographic and ecologic orders.     

Analyse de populations d'isastrées bajociennes (Scléractiniaires jurassiques de France). Conséquences taxonomiques stratigraphiques et paléoécologiques

The present statistical study of two Bajocian populationsof Isastrea from eastern France uses different methods of measurement taking into account the colonial character. The results of the univariate and the multivariate analyses together with direct observation of qualitative characters show that only two species are present in the samples: Isastrea bernardiana and I.tenuistriata. A new synonymy is suggested for the Bajocian species. Genera such as Andemantastraea All. and Parisastraea All. correspond to the common variation of Isastrea. The taxonomic position of other Jurassic Isastrea is examined. It is probably possible to use extreme morphotypes as stratigraphic markers owing to an eventual anagenesis.A comparison between the two samples denotes that the variation range or the mean value of some quantitative characters (number, thickness of septa, dimension of corallites, trabecular density) contributes to the paleoecological interpretation.The present paper emphasizes the necessity ofwell-defined species based preferably on population study, for a reliable generic definition.     

Temps et réseaux de l’art paléolithique : la grotte de La Covaciella (Asturies,Espagne)

The study of graphic convergences and divergences in Palaeolithic art is used to understand the culture, territories and interaction systems of human groups. La Covaciella cave has fifteen animal representations and other linear, dots and geometric motifs. The bison stands out; some were executed with complex technical procedures. Two of them were dated by C14 AMS, obtaining a result of 14,260 ± 130 BP (17,733–16,973 cal BP) and 14,060 ± 140 BP (17,503–16,260 cal BP). These correspond chronologically with the beginning of the middle Magdalenian or the very end of the lower Magdalenian. Similar depictions to the bison at La Covaciella are located in other areas of Western Europe. The repertoire of parietal bison displaying graphic similarities with those at La Covaciella is very large; both of the Pyrenean model (Niaux morphotype) and of the Perigordian model (Font-de-Gaume morphotype). A first consideration derived from the search for comparisons involves a new interpretation of the territorial value implied by the term Pyrenean style (Asturias, Cantabria, Basque Country, Navarre, Pyrénées-Atlantiques, Hautes-Pyrénées, Haute-Garonne, Ariège, Dordogne, Lot, Ardèche and Vienne). The Font-de-Gaume parietal morphotype is most common in Dordogne. In addition, in some cases, spatial complementariness has been found, with both graphic morphotypes. This article proposes different chronological and anthropological hypothesis to explain the distribution and coexistence of the two graphic models.     

Découverte d'une faune de vertébrés dans l'Oligocène inférieur de Vayres-sur-Essonne (bassin de Paris,France) : biodiversité et paléoenvironnement

The new rich vertebrates deposit from the Lower Oligocene, at Vayres-sur-Essonne (Essonne, France), contains 34 marine and seven continental taxa, 17 taxa being recorded for the first time from the Paris Basin. The richness of the ichtyofauna is higher than in anyone of the Parisian Oligocene deposits and equals the one of the ‘Argiles de Boom’ (Belgian Rupelian). Its affinities with the septentrional ichtyofauna is confirmed, meridional elements being rare. The terrestrial fauna, the oldest known from stratotypical Stampian (base of the Upper Stampian) shares affinities with the one of Montalbán and attests the occurrence of nearly freshwater environments. To cite this article: D. Merle et al., C. R. Palevol 1 (2002) 111–116.     

Nouveaux sites paléolithiques de l’oasis de Djizak

The present paper is devoted to the study of Paleolithic settlements recently discovered in the territory of the Djizak Oasis. Some Paleolithic settlements such as Yangikichlak, Azimboulak, Gourdara 1, 2 and Shachmai-Doston were discovered at the roof of the Nourata mountain range in the Farich district. Their cultural layers are not conserved but the single discoveries testify to the presence of prehistoric human camps in the Upper Paleolithic period. The lithic assemblage from the sites of the Djizak Oasis has some similarities with the material coming from the Tachkent site complex and from the Samarkand drainage basin. The discovery of the settlements and their later studies fill gaps on the Paleolithic map of the region.     

Les colorants dans l’art pariétal et mobilier paléolithique de La Garma (Cantabrie,Espagne)

La Garma Cave is an Upper Palaeolithic site located ca 15 km from Santander (Cantabria, Spain). The lower gallery, which is accessible thanks to two wells, keeps paintings on the walls and numerous objects laying on the floor, objects made in bone or antler which are carved, engraved and painted. The analysis of more than 50 samples taken from the walls or the objects (37 red, 11 black, five yellow, two brown, one purple) takes part in the global project of the “chaîne opératoire” comprehension of the prehistoric painting activity. The analysis is aimed also to understand the organisation of La Garma cave, looking for the various steps of the decoration of the different rooms. The results bring to light the modulated realisation of the wall paintings: few figures were painted rapidly without any specific intention, the majority, on the other hand, were realised after a complex preparation of the painting matter with the use of specific paint pots.     

La paléoflore autuno-stéphanienne de la région de Demnate(Est de Marrakech-Maroc)

The paleoflora described and pictured in this paper has been collected in two deposits of the area of Demnate: the OT6 bis drilling in the oriental Haouz and an exposure in the Rhojdamas (High-Atlas). Two completely different associations have been characterized: one hygrophilous and autochtonous of the «Stephanian type and the other mesoxerophilous and allochtonous (vegetation of the upland?) of the «Autunian type. In the OT6 bis drilling, the two floras alternate so that it is impossible to draw a precise boundary between the Stephanian and Autunian. In the Rhojdamas, only the Autunian flora has been identified. Such a combination of the two floras has similarly been recorded in several stephanian basins of the French Massif Central.     

Faunes d'oiseaux du pléistocène de France: Systématique, évolution et adaptation,interprétation paléoclimatique

Statistical comparison between bird populations from Lower and Middle Pleistocene and present ones makes it possible to demonstrate evolutionnary shifts such as increase in size or, on the contrary, decrease in size in some lineages and to discover some species or subspecies already found in Central Europe, in layers of the same epoch. In some other lineages the observed variations seem to be regarded as possible adaptations to local geographical conditions.Moreover the study of the birds contributes richly to the reconstitution of climates and biotops. The percentage variations of «cold birds in a given site makes it possible to confirm climatic fluctuations already discovered by other methods of study.     

Les faunes coralliennes de l’Oligocène de Malte : biodiversité et paléoenvironnement

The study of the coral biodiversity of the Upper Oligocene sedimentary series (Lower Coralline Limestone, Chattian) of Malta permitted the identification of 25 scleractinian genera represented by 41 species. Three new species are proposed: Miophora naxxarensis n. sp., Nerthastraea maltensis n. sp. and Gyrosmilia maltensis n. sp. Observations made in various Oligocene sites in Malta, especially around Naxxar and Tal Bajjada, allow to establish a suite of coral associations which may vary spatially and vertically. The identified scleractinian associations can be represented by different types of coral assemblages and bioconstructions: isolated colonies, coral beds of varying density but of large spatial extent, more cohesive coral banks (coral carpets) or patch reefs forming morphologies with gentle lateral slopes. The colonial morphologies are closely linked to these different types of bioconstructions. These coral constructions have been established and developed in shallow marine areas. The coral biodiversity of the Oligocene of Malta fits well in the evolution of the Cenozoic reef phenomenon whose development reached its peak in the Oligocene with great coral richness in the Chattian in the Mediterranean area.     

Les remplissages sédimentaires des coquilles de céphalopodes triasiques. Mécanismes et intérêt paléoécologique

Experiments have been carried out in laboratory onplastic cephalopod models in order to study most aspects of sedimentary shell filling of Ceratites and Nautilus from the German Upper Muschelkalk. In most cases the shells had a horizontal position when being filled by the sediment. The exception of filling in upright position has been observed mainly for Ceratites nodosus nodosus (Bruguière, 1792), Acanthoceratites spinosus (Philippi, 1901) except the species A. spinosus penndorfi (Rothe, 1955), Acanthoceratites evolutus (Philippi, 1901) and the nautilus Germanonautilus bidorsatus (Schlotheim, 1804); it is due to the width of their shells. In no case the sediment filling of cephalopod shells gives information about the depth of the depositional environment. On the other hand it is a good indicator of the waving occurring on the sea floor and the reworking of the sediment.     

Les ostracodes et l'évolution paléogéographiqueau quaternaire récent du site d'Ashtart (golfe de gabès,tunisie orientale)

enTwenty-seven samples have been collected in AshtartBasin (Pelagian Sea), along the core KST 100. Studies on ostracods species enables us to recognize four main associations from - 27 000 years to the Recent; the first can be linked to the Würm III regression and the other ones to the Versilian transgression.     

Lutte biologique et intégrée en vergers de pommiers,poiriers et abricotiers

Résumé La lutte biologique contre les organismes nuisibles aux vergers évolue par étape vers une Protection intégrée. Dans cette optique, les recherches se développent en France sur les points suivants: effets indésirables des pesticides sur l'entomofaune auxiliaire, r?le d'abri-refuge pour l'entomofaune autochtone joué par l'environnement végétal des vergers, diversification des procédés de lutte, mise au point de méthodes plus sélectives, sélection de variétés résistantes ou moins sensibles aux attaques de plusieurs organismes nuisibles, amélioration des méthodes de surveillance des vergers pour la prévision des risques de dégats, lutte raisonnée contre les maladies cryptogamiques. La mise au point de programmes de lutte intégrée dépend essentiellement des possibilités de lutte disponibles contre les ennemis-clés. Dans les vergers de pommiers et de poiriers fran?ais, les ennemis-clés appartiennent à groupes d'arthropodes: Carpocapse (Cydia pomonella L.), Tordeuses de la pelure, Aphides, Psylle du poirier (Psylla pyri L.) Acariens phytophages et aussi à trois maladies fongiques: Tavelure du pommier (Venturia inaequalis Cke.) Wint., O?dium du pommier (Podosphaera leucotricha Ell. et Ev.), Tavelure du poirier (Venturia pirina (Bref.) Aderh. Les méthodes de lutte sélective sont passées en revue: régulateurs de croissance des insectes, lutte biologique par lachers de parasites et de prédateurs insecticide microbiologique, lutte par confusion avec les phéromones sexuelles. L'application de certaines d'entre elles dépend des possibilités de production industrielles d'agents biologique ou biotechnique. Les principaux éléments ayant contribué à une application pratique des programmes de lutte raisonnée et de lutte intégrée ont été: l'amélioration des connaissances biologiques et de la nuisibilité des organismes phytophages, ainsi que des méthodes de surveillance et de prévision permettant l'utilisation des seuils de tolérance économique l'aménagement de la lutte chimique contre le Carpocapse en vergers de pommiers, la démonstration de la bonne efficacité des prédateurs du Psylle du poirier, spécialement desAnthocoris. La lutte raisonnée, appliquée sur plusieurs milliers d'hectares de vergers de pommiers et de poiriers en France, a permis de réduire de plus de 50% le nombre de traitements avec un bon niveau économique de protection. Dans les vergers d'abricotiers, les maladies parasitaires, principalement l'Enroulement chlorotique causé par un mycoplasme, représentent les problèmes les plus importants. Des essais sont en cours pour parvenir à une lutte raisonnée contre la Petite mineuse (Anarsia lineatella Zell.) et le puceronHyalopterus pruni Geoffr. qui est l'agent de dissémination de la Sharka (maladie due à un virus de type I.L.A.R.).      

Les bélemnites de la carrière de Serra San Quirico (Province d'Ancona,Apennin Central,Italie) et la paléobiogéographie des Bélemnites de la Téthys Méditerranéenne au Tithonique inférieur

About a hundred belemnites, together with numerous other fossils, were collected in a quarry near Serra San Quirico (Ancona Province, Central Apennines). The belemnite fauna is studied with a palaeontological — systematical and palaeogeographical regard. In regard to systematics, thirteen species ascribed to five genera are described, particularly Duvalia apenninica nov. sp., D. aesinensis nov. sp., Rhopaloteuthis siciliensis nov. sp. and Quiricobelus italicus nov. gen., nov. sp., of the Diplobelidae family. During the Tithonian, this family was represented, up to day, only by the genus Diplobelus.According to literature, the geographical distribution of the species recognized in the quarry of Serra San Quirico allows us to think that in a mobilist palaeogeography, the Apulian plate was a diffusion center, with an evident dispersion towards the southern margin of the euroasiatic craton, from Spain to Iran. The African margin, with the exception of Sicily, does not seem to have been affected by this dispersion, probably for palaeogeographic reasons.     

Découverte de faunes d'Ammonites de la zone à Platynota(Kimméridgien inférieur) dans les Monts de Chellala (avant-pays Tellien,Algérie); Conséquences stratigraphiques et paléogéographiques

In Chellala mountains (Seba el Abiod), in Western Algeria, new biostratigraphic data, based on Ammonites, allow characterize, for the first time in North Africa, the Platynota zone with the species-index Sutneria platynota. This species was known, to the present time, only in the South European border. These new biostratigraphic data show the diachronism of flyschoid facies. They do not exceed middle Oxfordian in the Tlemcenian zone; on the contrary they go up to lower Kimmeridgian in the preatlasic zone.     

Une faune inédite de coraux scléractiniaires dans le gisement chattien d'Escornebéou (Landes,SW France) ; stratigraphie,systématique et paléoécologie

The Escornebéou locality (Landes, SW Aquitaine Basin) is a reference site for the marine Chattian of atlantic tropical type. The abundant microorganisms allowed these outcrops to be allocated to the classic biozonations, after numerous historical controversies about their age. A fauna of Scleractinian corals has been discovered there for the first time, mainly from the ‘Le Bois’ site. About 25 taxa are listed and their systematics is analysed. They split up into 18 genera and subgenera, with stratigraphically a cachet intermediate between the Oligocene and Miocene faunas. There are as many solitary species as colonial ones (mainly hermatypics). The presence of numerous reefal genera confirms the tropical (to subtropical) paleoclimate, as well as the data from the other present organisms. Concerning the coarse zoogene calcareous deposits from ‘Le Bois’ (where the coral colonies are massive), the environment was shallow, fairly turbulent and under the effect of currents and waves. A subreefal facies locally developed (with mixed hermatypic and ahermatypic corals), belonging to the paleogeographic domain of shoal-type or barrier-type bioclastic limestones, as recognized elsewhere. At Escornebéou, the outcropping sequence is mainly marly to fine-grained sandy-marly (including such coarse calcareous intercalations), as at Lespeyrères, where few corals have also been found. These calm environments, of sheltered marine mud flat or seaweed type, were not very favourable to coral growth.