Les échinides du Turonien de la Formation de l’Azilé du bassin côtier gabonais dans la région de Libreville Sud

Study of Turonian echinoids from Gabon store section allowed us to distinguish 10 species belonging to 2 genera: Mecaster pseudofourneli (Péron et Gauthier 1878), Mecaster toucasanus (d’Orbigny, 1854), Mecaster africanus (Coquand, 1862), Mecaster semicavatus (Peron et Gauthier 1880), Mecaster verneuili (Desor, 1847), Mecaster cf. orbignyanus (Desor, 1857), Mecaster palpebratus (Loriol, 1888), Mecaster sp.1, Mecaster sp. 2, Epiaster michelini (Agassiz) 1847. All species are found for the first time in Gabonese coastal basin. The composition and the distribution of echinoids fauna and the sedimentary characteristics indicate a proximal shallow platform deposit environment, with warm water and soft substrate. Two types of depositional environment are suggested: (1) a deep part of the proximal platform, represented by silty limestones and (2) a shallower part of the proximal platform, represented by limestones.     

Les prémices d'une agriculture diversifiée à la fin du Mésolithique dans le Val de Loire (Loire armoricaine,France)

Pollen analyses carried out in the Armorican Massif have already drawn our attention to the early appearance (at the end of the Mesolithic period/beginning of the Neolithic period) of several taxa, particularly Cerealia. New studies conducted in the Val de Loire region of France and in the surrounding tributaries seem to confirm these initial findings. These studies also provided more information about the introduction of Fagopyrum and Juglans at about 6000 BC. We hypothesise that ‘pre-domesticated’ agriculture took place in this area at this time and that it might have been brought to this area by southern migration. To cite this article: L. Visset et al., C. R. Palevol 1 (2002) 51–58.     

Hommes et climats au Paléolithique supérieur dans le bassin de la Somme (France)

Nearly 40 years of intensive research conducted in the Somme basin has demonstrated the discontinuity in the human occupation of the area during the Upper Palaeolithic. The northern position of the Somme basin within the loessic region appears to be an explanatory factor in this discontinuity, the nature of which increasingly appears related to climate and environmental factors. Archaeological occupations have been systematically attributed to phases of warming or climate improvement. On the other hand, an absence of human occupation has been consistently observed during the coldest periods. The extreme poverty of the biomass contemporary to the loessic deposits of the Upper Pleniglacial could partly explain this discontinuity specific to the far northwest of Europe (southern England, northern Belgium, Netherlands, and northern Germany). Although only 150 or 200 km away, the southern Paris Basin, which is located on the fringes of the loessic region of northern France and Normandy, presents a more continuous human occupation, which appears to have benefitted from more favourable conditions.     

Les supports morphologiques de l'intégration dans la colonie de Veretillum cynomorium Pall. (Cnidaria,Penntularia)

The morphological supports of integration, including the nervous system, are to be found.After a morphological observation, ecto and endoderms and their intercellular junctions are presented.The regionally different mesogleal synaptic nerve nets are surrounded by ecto and endodermal nervous structures.The presence of behavioural activity centers is also discussed.

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Liste des abréviations des figures AS autozoïde sectionné - AU autozoïde - CAL canal longitudinal - CAV cavité gastrique - CC corps compact - CGL cellule globuleuse myo-épitheliale MESlame mésentériale MF microfilament - CGR cellule granuleuse myo-épithéliale - CLC cloison commune à deux autozoïdes - CLR cloison radiale - CLT cloison transversale - CM corps myélinique - CME cellule mesenchymateuse - CNE cellule nerveuse ectodermique - CNEN cellule nerveuse endodermique - CNM cellule nerveuse mésogléenne - COL colonne - CSP cellule spumeuse - CSPH cellule sphéruleuse - CU cellule urticante - D dépot de matériel intercellulaire (zonula adhaerens) - DS desmosome septé - ECT ectoderme - EE empilement d'ergastoplasme rappelant un corps de Nissl - FF fibres fasciculées h structure - G glycogène - GA granule aréolé - IC inclusion crênelée - M mitochondrie - MB membrane basale - ME mésoglée - MES lame mésentériale - MF microfilament - MT figure interprétée on terme de microtubule - MV microvilli - N noyau - E neurite - NO nodosité - P pédoncule - PC paroi des canaux - PE perforation - R rachis - SF siphonozoïde fendu - SIPH siphonozoïde - SM sipment musculaire d'une cellule myoépithéliale - T travé ous-siphonozoïdale - TME travée mésogléenne - VC vésicule claire - VME vésicule mésenchymateuse - ZI zône intermédiaire - I synapse polarisée - 2 synapse réciproque - 3 figure ressemblant à un desmosome septé - 4 contact par apposition Cc travail correspond à la première partie d'une thèse de Doctorat d'Etat, consacrée aux «Structures et aux mécanismes de l'intégration dans la colonie de Veretillum cynomoriurra» — Il a été effectué au sein de l'Equipe de Recherche Associée au C.N.R.S., n°183 (Directeur Al. Pavans de Ceccatty) avec le concours du Laboratoire Arago à Banyuls sur Mer (France) et la collaboration technique de Madame J. Villeneuve.     

Observations sur la végétation nitrophile de lisière dans les Marches (Italie Centrale)

A survey of the nitrophilous fringe communities of the region Marche (Central Italy) allows the individualization of five associations well characterized floristically and ecologically. These are:Urtico-Aegopodietum, Anthriscetum sylvestris, Chaerophylletum aurei, Alliario-Chaerophylletum temuli, andAnthriscetum nemorosae. The first three associations are ranged, from the phytosociological point of view, in the allianceAegopodion podagrariae, while the last two belong to the allianceGalio-Alliarion.     

Les groupements végétaux du bassin de la sambre française

Sans résuméReçu par la rédaction le 5.1.1960     

Les éperons stipulaires de la Glycine (Wisteria sinensis Sweet)

Summary InWisteria sinensis, two little spurs are found under the deciduous stipules. They are vascularized by fairly complex bends of both lateral bundles, in much the same way as the dorsal spur ofAsparagus leafscale is by the median.     

Les néandertaliens de la Caverna delle Fate (Finale Ligure,Italie). II – Les dents

The neandertalian remains discovered in the Caverna delle Fate, Finale Ligure (Italy) gave up a majority of dental material: 10 isolated teeth and six teeth upon arcade or included in the adult mandible Fate 3 and in the child mandible 8–10 years old, Fate 2. Until now, this assemblage is the most numerous of neandertalian teeth excavated in Italy, with archeostratigraphic and paleoenvironmental accurate context. No decidual tooth, lost naturally, has been recognized. The dental material is well preserved, not much altered by wear. The morphometric data confirm the possibility of presence of a gracile neandertalian population living along the mediterranean septentrional European shore. These populations were present since the MIS 5.1, between 80,000 and 70,000 years. This gracility can be explained by the geographic impact and not by the evolutive stage.     

Les assemblages de diatomées des niveaux infra-gypseux du bassin messinien de Sorbas (Espagne)

In the Sorbas basin, the diatomites represent one of the main sedimentary components of the Messinian together with its two marginal carbonate platforms and the central gypsum deposits. Several vertical sections were taken in the infra-gypsum diatomites from successively more distal paleogeographic areas, ranging from the reef slopes (Cariatiz) to the basin (Los Yesos, Los Molinos). A total of 88 diatom species were determined: 50 centric and 38 pennate. Characteristic assemblages were defined for each category type, revealing ecological variations. In the three sections, plankton forms represent 90 % of the diatoms, with oceanic forms dominating the meroplanktonic and neritic. Nevertheless, some levels clearly indicate a coastal environment, attesting to the carbonate platform influence which progrades toward the basin. The diatom assemblages are relatively homogeneous throughout the three sections, indicating that, before gypsum deposition, the basin was still substantially open to the ocean, with waters sufficiently warm to allow coral reef development. Nevertheless, the basin might also have experienced episodes of colder Atlantic influences.     

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.     

Les Brachiopodes de la craie blanche de Meudon (Campanien supérieur) de la collection dˈOrbigny (MNHN,Paris)

Brachiopods from the White Chalk of Meudon (Upper Campanian), listed in the catalogue of dˈOrbigny collection, are presented following the revised classification. This is not without difficulty, due to the few specimens found and/or to the heterogeneity of sets listed under the same number and labelled with the same name. The Brachiopod fauna in the Belemnitella mucronata Zone is well represented, considering the Invertebrate fauna as a whole. Two representatives of Craniiformea and about ten species of Rhynchonelliformea, from several superfamilies shared by two orders, are critically described, considering the recent observations and the last works after dˈOrbigny.     

Diatomées épilithiques du fleuve Esino (Italie centrale) et leur utilisation pour l'évaluation de la qualité biologique de l'eau

In the monitoring programme of the Italian rivers which enter the Adriatic Sea, a relatively closed and small sea with high pollution risk, the assessment of the water quality of the River Esino, a typical central Apennine watercourse, was carried out. The eutrophication/pollution index (EPI-D) proposed for Italian rivers and based on the sensitivity of the diatoms to organic matter, nutrients and mineralization of the water, with particular reference to chloride, was adopted in this analysis. The good results obtained with respect to the various situations of pollution present at the eighteen stations selected along the river, as well as with regard to other diatom-based indices generally used in Europe, seem to confirm the validity of this index for monitoring Italian watercourses.     

Alcide d’Orbigny,un précurseur dans l’étude de la faune du Danien du bassin de Paris

One of the major contributions of Alcide d’Orbigny to palaeontology is his work on the Danian of the Paris Basin. The Danian material includes well-preserved external imprints of Invertebrates. By making casting of these imprints, Alcide d’Orbigny inaugurated an original technique, which enabled him to describe more than 40 species. The question of the age of the Danian localities has long been debated since that time. It was settled once and for all in the seventies by micropalaeontologists.