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.     

Nouvelles données paléontologiques,paléoécologiques et sédimentologiques sur le Berriasien de la région de Lamoricière (ouled Mimoun et E1 Rhoraf,Monts de Tlemcen,Algérie)

In the Western Algerian area, the Ouled Mimoun and El Rhoraf sections are particularly appropriate for the study concerning the berriasian formations.From tha lithostratigraphical point of view, the upper section of the carbonated platform corresponds to the lower Berriasian and a part of the middle Berriasian. The «Argiles de Lamoricière which dominate it belong to the middle and upper Berriasian. The subjacent detritic formation known as «Grès de Berthelot probably begins with the lower Valanginian. The stratigraphical results are based on an abundant fauna (ammonites, ostracods) collected in situ, the main species of which have been the subject of a paleontological review and abondantly illustrated.The studied series offer a good example of the evolution of sedimentary conditions which accompany the temporary opening of a carbonated platform towards the open sea.The variations in fauna composition are closely related to changes in environment. In particular, the presence of ammonites in the Boissieri zone can be connected to the highest point of marine advance, although the depth remained relatively shallow (an upper infratidal zone being likely). It is to note that during this period the low level of sedimentary activity favored the settling of some remarkable epilithic fauna.Above the «Argiles de Lamoricière, the massive detritic sedimentation (grès de Berthelot) could indicate an important paleogeographical change in the interior. In the area studied, the ostracods encountered in the basal section of the last formation still mean a shallow marine environment.     

Synthèses et réductions de sucres fonctionnels mono et diinsaturés

Attempts to prepare 1,2:5,6 and 2,3:5,6 di-unsaturated sugars starting from 3,4,6-tri-O-acetyl-1,5-anhydro-1,2-dideo xy-d-arabino-hex-1-enitol or from ethyl 4,6-di-O-acetyl-1,5-anhydro-2,3-dideoxy-α-d-erythro-hex-2-enopyranoside led to 1,5-anhydro-1,2,6-trideoxy-l-threo-hex-5-enitol and its 3,4-diacetate. Hydrogenation and hydrogenolysis of the unsaturated chloro and fluoro derivatives afforded 1,5-anhydro-1,2,6-trideoxy-d-arabino-hexitol and ethyl 4-O-acetyl-2,3,6-trideoxy-α-d-erythro-hexopyranoside.     

Assemblages et chaînages de fichiers cartes dans un système automatisé: Une application en paléontologie

enThe storage of taxonomical, stratigraphical, geographicaland bibliographical data, some being coded, about ammonites from Upper Jurassic has begun since 1972 and constituts three files with punch-cards: types, citations and synonymies. The disappearing of punch-cards leads to the making of a system with software allowing the combination and the chaining of files. The combination allows the gathering of data from different files and the chaining, thanks to decoding files the translation in clear of coded data.Simplicity in the procedures, swiftness in the execution and printing in clear are the principal advantages of the use of the software Texto.     

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.     

L'évolution des gastéropodes lacustres et la paléoéologie des diatomées dans le Néogène de Kos (Dodécanèse,Grèce)

Evolutionary lineages of several limnic gastropod genera (Viviparus, Melanopsis, Theodoxus) from the Neogene of Kos island (Dodecanese, Greece) are described and interpreted. The attempt is made to analyse the paleoecological development of a limnic sedimentary basin in the eastern portion of Kos by means of Diatoms. Obviously, there is no relation between the chemical parameters of the water of the former lake and the morphological development of the gastropods. The lineages of Viviparus brevis, Theodoxus doricus and Melanopsis gorceixi are suggested to be caused by phyletic transformations and not by changing environmental conditions. It is, thus, possible to establish a local biostratigraphy based on subspecies, and moreover, a more regional one based on longer ranging species.     

Découverte de Foraminifères planctoniques paléocènes dans les brèches,précédemment tenues pour aptiennes et d'origine diapirique,des Pyrénées basco-béarnaises

After the dating, by means of planktonic Foraminifera, of post-metamorphic marine breccias, Upper Danian–Lower Selandian in age, associated to hemipelagites and unconformably overlying the Cretaceous tectogenic axis of the Pyrenees from Roussillon to Bigorre, was it possible to extend westwards the breccia-filled Palaeocene ‘trough’ as far as the ‘Zone des Chaı̂nons béarnais’? This later unit, which belonged to the North-Iberian palaeomargin during Lower Cretaceous, was previously considered by several authors as characterized by an important halokinesis generating, during Aptian/?Albian, collapses of the Jurassic–Lower Cretaceous carbonate cover above dissolved salt domes and spectacular accumulations of breccias. In fact, we have everywhere identified Palaeocene planktonic microfauna within the matrix of these breccias (and within the associated hemipelagites), particularly of the reference ‘diapiric’ breccias of Etchebar, Lauriolle, Layens and Bosmendiette/Beloscare. Deposited into intra- ‘trough’ sub-marine canyons, after karstification and erosion of intermediate mountains with a steep topography previously induced by Uppermost Cretaceous compressions, the herein studied Palaeocene marine breccias should not be hereafter regarded as linked to any Lower Cretaceous diapirism on the North-Iberian palaeomargin. To cite this article: B. Peybernès et al., C. R. Palevol 1 (2002) 3–10.     

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.     

Le bassin lacustre miocène de Bes-Konak (anatolie-turquie): Géologie et introduction a la paléontologie des vertébrés

The tertiary lacustrine and marshy facies ofBes-Konak (Ankara-district) has provided a rich fauna of Vertebrates preserved as molds and casts in Diatomites and volcano-sedimentary beds.In this assemblage are: Cyprinid fishes (Leuciscus(P.) etiliusRückert Ulkümen) with among them a new species of Barbus, some Amphibians both Urodela (mature Triturinae) and Anura (larval forms of Pelobates sp. and mature Rana sp.), a Turtle (Chelydridae-Chelydropsis sp.) a Snake (Colubroïde-Colubridae or Viperidae) and Birds (among them a new species of cormorant).According to the others various data resulting from palaebotanical, palynological and structural investigations, this fauna is clearly suggestive of a lower or middle Miocene deposit. It supports readily the climatic features (local sub-tropical microclimate inside a regional hot-temperate context) as invertebrates, macro and microflora and sedimentology had already shown.Once more, it points out the peculiar trophic type of the limnic area of Bes-Konak and its evolution to a well-marked eutrophic condition.     

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.     

Signification paléoécologique et paléogéographique des bivalves du Carbonifère inférieur du bassin d’Ancenis (Massif armoricain)

Palaeoecological and palaeogeographical inferences from Early Carboniferous bivalves of the Ancenis Basin (Variscan belt, France). In the basal part of the Ancenis Formation, of Dinantian age, greenish to purple mudstones display a few bivalves, assigned to the genera Lithophaga, Modiolus, and Naiadites. Because Naiadites is considered to be a non-marine bivalve, and is only previously reported in Scotland in Dinantian rocks, a brackish environment can be assumed for the Ancenis Basin during the Early Carboniferous. To cite this article: M. Ballèvre, H. Lardeux, C. R. Palevol 4 (2005).     

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.     

Isolement et sélection de souches d'actinomycètes productrices de substances antifongiques de structure non-polyénique

Résumé Dans le but d'étudier des souches d'actinomycètes productrices de substances antifongiques de structure non-polyénique, 13, échantillons de sol prélevés dans le sud de la France ont été examinés. L'utilisation de milieux sélectifs a permis d'isoler 486 souches d'actinomycètes qui ont été testées vis-à-vis de quatre espèces de champignons et de levures: 18% des souches isolées sont actives sur au moins l'une des espèces utilisées. Parmi celles-ci 14 souches, productrices de substances de structure non-polyénique, ont été sélectionnées après étude des spectres d'absorption en UV des surnageants de culture, des extraits butanoliques de ces surnageants ou des extraits méthanoliques de mycélium. L'utilisation d'un test bactérien de toxicité à court terme (SOS Chromotest) a permis de montrer que 10 souches sur 14 présentent aussi une activité génotoxique.

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Summary In order to study actinomycete strains producing non-polyenic antifungal substances 13 soil samples were collected in S. France. By using selective media 486 strains of actinomycetes were isolated and tested on four species of moulds and yeasts: 18% of the isolated strains were active against one or more of the test organisms. From these isolates 14 producers of non-polyenic antifungal substances were selected by means of u.v. absorption spectra of culture supernatant fractions, butanol extracts of these fractions, or methanol extracts of mycelium. A rapid bacterial toxicity assay (SOS Chromotest) demonstrated that 10 of the 14 selected strains had genotoxic activity.

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Resumen Para el estudio de cepas de actinomicetes productores de sustancias antifúngicas no poliénicas, se recogieron 13 muestras de suelo en el S. de Francia. Utilizando medios selectivos se aislaron 486 cepas de actinomicetes que se ensayaron frente a cuatro especies de mohos y levaduras: 18% de las cepas aisladas mostraron actividad frente a uno o más de los organismos utilizados en el test. De estas cepas se seleccionaron 14 que eran productoras de sustancias antifúngicas no poliénicas mediante el espectro de absorción al U.V. de las fracciones sobrenadantes del cultivo, de extractos butanólicos de dichas fracciones o de extractos metanólicos del micelio. Un ensayo rápido de toxicidad bacteriana (SOS Chromotest) mostró que de las 14 cepas seleccionadas lo tenían actividad genotóxica.

     

Les relations ontogenèse-phylogenèse:Applications paléontologiques

After a short historical introduction, the principal notions used to study the connections between ontogeny and phylogeny are desribed. The three fondamental standards (shape, age, size) upon which are made ontogenetic comparisons are defined and discussed.The different ontogenetic heterochronies are described and illustrated with concrete paleontological examples. Successively are studied:u

1. -dwarfirsm and giantism which are particularcases;
2. -the 4 types of heterochrony which affect somatic development (neoteny and acceleration) or sexual maturation (hypermorphosis and progenesis);
3. -the innovations which are a fast appearence of a new character and their associations with the 4 elementary heterochronies.

The heterochronies are connected with phylogeny. This leads to the definition of two fondamental tendancies: paedomorphosis and peramorphosis; the terms proterogenesis and palingenesis are redefined. To conclude, this study is inserted in a more wider context that shows the importance of ontogenetic knowledge to understand numerous evolutif processes (tempos in evolution, demographic strategies, cladism).     

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.