Les crocodiliens fossiles du Jurassique moyen et supérieur de Bourgogne

The middle and upper Jurassic limestones of Côte-d'Or (France) contain some crocodilian remains referred to the genera Teleidosaurus, Steneosaurus, and Metriorhynchus. Their preservation allows a determination at a specific level only for Teleidosaurus gaudryi (Lower Bathonian), Steneosaurus larteti (Upper Bathonian), S. heberti and S. cf. intermedius (Middle Oxfordian). Sedimentological evidence shows that Steneosaurus and Teleidosaurus are found either in very pure limestones sedimented on an epicontinental platform, in a very calm and sheltered environment, in the intertidal or supratidal zone, often associated with subrecifal facies; or in the infratidal zone, more distinctly subjected to open-sea influences (deposits, currents, reworkings). Specialised Metriorhynchidae such as Metriorhynchus are completely absent in the former type of sediment but are present in the later. One may infer, considering anatomical evidence (no dermal armour, caudal fin…) that Metriorhynchus was better adapted to swimming and rather lived in the open sea. The Teleosauridae preferred very shallow or temporarily emerged places, where they could move around thanks to their limbs which were still capable of walking on land; however, this did not prevent them from going out to sea, where the habitats of both families probably largely overlapped.     

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.     

Eodmitria,genre nouveau de Brachiopode Cyrtospiriferidaedu Frasnien inférieur et moyen

A new genus Eodmitria (Brachiopod Spiriferida)with type-species: Spirifer supradisjunctus boloninensis n. subsp., typical of the lower and middle Frasnian, is defined. It is akin to DmitriaSidiachenko, 1961.     

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.     

Rôle de l’échographie dans le diagnostic des kystes ovariens et des masses annexielles,en dehors de la grossesse et de la stimulation ovarienne

This article contains the semiological bases used to characterize ovarian lesions in imaging, especially ultrasound.     

Corrélation de la biozonation des Charophytes avec celle des Foraminifères (Orbitolinidés dans le Valanginien inférieur du Bassin du Maestrat (Castellò, Espagne)

A correlation between the biozonations of orbitolinidsand charophytes is established in the Lower Valanginian from the Polacos Formation (Maestrat basin, Castelló, east of Spain). This correlation is based on the presence of the charophyte association: Perimneste micrandra-Perimneste ancora (rare), Globator trochiliscoides (primitive), Embergerella stellata, Flabellochara harrisii and Porocharaceae in the levels underlaying and overlaying the banks with the orbitolinid Valdanchella miliani. This charophyte assemblage is similar to the flora of the “Olba zone” from Grambast (1974), which was hypothetically attributed to the Hauterivian.According to our correlation, the olba flora was atleast already existing in the Lower Valanginian. Provisionally, the biostratigraphic boundary between the Berriasian and the Valanginian can be characterized in the continental domain of Tethys by the disappearance of Globator nurrensis and the first appearance of Embergerella stellata. Uncertainty still exists in the chronostratigraphy of the charophyte biozonation during the Middle Valanginian to Upper Hauterivan time interval.     

Végétation et climat au Pléistocène inférieur et moyen à La Pineta (Isernia,Italie)

Palynological investigation from the Lower Palaeolithic site of La Pineta (Isernia, Molise) reports the environmental and climatic conditions of an old human occupation site in Italy, between the end of the Lower Pleistocene and the beginning of the Middle Pleistocene. The pollen record shows that the end of the Lower Pleistocene was marked by an arid episode. This is related to change in the climatic cycles periodicity from 41 to 100 ka, which occurred between 900 and 800 ka. The post-archaeological layers show new favourable moisture conditions at the beginning of the Middle Pleistocene, when the 100 ka cycles prevail. To cite this article: V. Lebreton, C. R. Palevol 1 (2002) 11–17.     

L’utilisation de l’obsidienne au Paléolithique supérieur dans le nord-ouest de la Roumanie

Obsidian artefacts are numerous in the Upper Paleolithic sites of Northwest Romania. The use of obsidian begins during the Aurignacian and continues during the Gravettian, All the stages of the lithic reduction sequence are present. The obsidian tools are numerous in some sites. Non-destructive chemical analysis by X-ray fluorescence (XRF) was performed on 232 obsidian artefacts from five sites: Buşag, Remetea Şomoş I, Călineşti I, Boineşti and Turulung. The results show that Early/Middle Upper Paleolithic people in northwest Romania acquired their obsidian, directly or indirectly, from sources on the western flank of the Carpathians, up to 170 km away.     

Charles de Gerville et les premiers restes de Plesiosauria signalés dans le Jurassique inférieur de France (Hettangien,région de Valognes,Manche)

The historian, archaeologist, and naturalist Charles de Gerville (1769–1853) reported as early as January 1816 the presence of fossil bones in the quarries of the region of Valognes, in the department of Manche. These quarries exploited the “Calcaire de Valognes” and the underlying “Argiles et Calcaires d’Huberville”, both formations dated as Lower Hettangian (Lower Jurassic). De Gerville communicated to Jacques-Louis-Marin Defrance a watercolour drawing of one of these fossil bones, discovered in July 1820, in which it is possible to recognize a plesiosaur femur. This femur, as well as a fragment of rib and three vertebrae of Plesiosauria from de Gerville's collection, was then figured in a publication by Arcisse de Caumont, in 1825. The plesiosaur femur was later acquired by Pierre Tesson of Caen, who owned one of the most important collections of fossils in Normandy. The Tesson collection was later purchased in 1857 by the British Museum (now The Natural History Museum, London), where the femur has been rediscovered. This specimen is the first known plesiosaur specimen ever discovered in the Lower Jurassic of France, before the genus Plesiosaurus was established upon material from the Lias of southwestern England. One of the vertebrae figured by de Caumont has been rediscovered in the “Muséum Emmanuel-Liais” (Cherbourg-en-Cotentin), which had acquired part of de Gerville's collection. The interpretation of the “fossil bones of Valognes” by Georges Cuvier, Henri Marie Ducrotay de Blainville, Arcisse de Caumont, Jacques-Amand Eudes-Deslongchamps and Constant Duméril is revealed through unpublished documents.     

Stratigraphie du Jurassique supérieur du djebel Bechtout au Nord-Ouest de tiaret (Bordure sud-tellienne,Algérie); Comparaison avec le Bou Rheddou

The study of the Upper Jurassic of the Bechtout Mountain (Southern Tellian border) allows us to distinguish five formations and to precise their age assignment owing to new collections of ammonites. Previous stratigraphic assignments are modified. Stratigraphic and sedimentologic data give evidence that each of the five Bechtout formations can be correlated with those encountered in the Bou Rheddou Mountain. As in the Bou Rheddou, first beds with ammonites are Middle Oxfordian in age. The Oxfordian «Ammonitico rosso facies begins in the Transversarium Zone up to the Planula Zone. The uppermost formation (Calcaires médians du Bou Rheddou) that begins in the Upper Oxfordian (Planula Zone) is essentially Kimmeridgian what causes us to exclude the time range Portlandian-Lower Cretaceous previously assumed.     

Paléobiogéographie de quelques Stephanocerataceae (Ammonitina) du Jurassique moyen et supérieur; une confrontation avec la théorie mobiliste

From Bajocian to lower Kimmeridgian, the subfamilyStephanocerataceae represents a large stock of the ammonite fauna. Though it is tributary of author's stratigraphical correlations and systematical interpretations, its geographical distribution with a drifting continents concept gives many teaching about the study of this superfamily, the continental drift and its consequences. Showing a world wide repartition at its apparition this stock then presents branches; the one (Stephanoceratidae) is not envisaged here; the second (Sphaeroceratidae and Cardioceratidae families) characterises rather the «boreal province; the third (Macrocephalitidae family) is chiefly specific of the «tethysian province. A «north-east pacific province with boreal affinities and a «south-east province with tethysian affinities are delimited. It is probably from its fauna that the tethysian macrocephalitid stock appears; first represented by ammonites specifically north american in middle and upper Bathonian stage, they extend during upper Bathonian and lower Callovian and reach South America and the Tethys. The presence of a narrow sea, on Patagonia, West Antarctica, East Africa, Madagascar and India, joining the Tethys and the south edge of Gondwania, is proved at various times, at Bajocian and Callovian stages.     

Le genre Tornquistes(Ammonitina,Pachyceratidae) á l'Oxfordien inférieur et moyen en Europe occidentale

TornquistesLemoine, considered still now as a subgenusof Pachyceras is up graduated to a genus level in the family PachyceratidaeBuckman. The study of this genus, only known in the upper part of Lower Oxfordian and the lower part of the Middle Oxfordian, shows six species; one of them, T. multicostatum, is new. These species are put in two sub-genus, Tornquistes s. str. and a new subgenus, Pachytornquistes. Some species are polymorph and for the first time, macroconch-microconch dimorphism is proved. Phyletic connections, stratigraphic repartition, paleobiogeographic distribution and their consequences are pointed out in conclusion.     

Caractères ornementaux,disparité et diversité chez les Ammonitina : exemple des Kosmoceratinae (Stephanoceratoidea), Callovien moyen et supérieur (Jurassique moyen,Bassin parisien)

The Kosmoceratinae Tintant, 1963, consist of a subfamily of Jurassic Ammonitina of boreal origin, of which most species are highly polymorphic. Because of their rapid evolution and diversification they represent a major group for establishing Middle to Upper Callovian biostratigraphy. During its history, this taxon records an extreme and sudden diversification across the boundary between the substages. This step took place according to two distinct modes: 1- a rather progressive although rapid increase in both diversity and disparity of the dominant groups during most of the Middle Callovian; 2- a sudden two steps renewal of ornamental patterns giving rise to a quick reorientation of both disparity and diversity. This double event is well recorded and synchronous at the European scale.     

Réinterprétation de Peltoceratoides athletoides (Lahusen), 1883 (Ammonitina,Aspidoceratidae). Conséquences sur la biozonation du Callovien supérieur et de l'Oxfordien inférieur

Peltoceratoides athletoides (Lahusen) is currently used in the Tethyan domain (Submediterranean province) as an index-species for two separate biochronological units: one a horizon near the top of the Callovian, the other a zone at the base of the Oxfordian. Paleontological revision of the species, from specimens collected in situ in South East France and in Normandy shows that species is strictly localized in the lowermost Oxfordian. Consequently, the Callovian horizon, originally defined in Anjou, should be renamed the Schroederi horizon. The usefulness of Peltoceratoides athletoides as an indicator of the first Oxfordian zone in the Tethyan domain, the counterpart of the Mariae zone, is confirmed. In addition, strict localization of the species makes it is possible to define a subzone and a horizon for the base of the Oxfordian, which are the boreal equivalents of the Scarburgense subzone and Scarburgense horizon. These new data contribute to build a standard West Tethyan scale entirely independant of the boreal zonation for the Upper Callovian and Lower Oxfordian.     

Chronologie des sites du Pléistocène inférieur et moyen du nord de l’Afrique

North Africa, and in particular the Maghreb, is a key region for African prehistory in that it contains sites whose chronology covers the entire Pleistocene period from 2.5 Ma to the Holocene. In terms of culture, it fits into the general pattern of the Stone Age, but it has particularities that make it a region apart with its own cultures. Due to its climate and geographical position, between the desert regions of the south and the Mediterranean Sea to the north, it has offered mankind a diversity of landscapes and environments that are quite unique and favorable to the development of human evolution. Finally, this region gives access to Europe through several maritime passages (Gibraltar, Sicily), which were probably used during the Pleistocene, thus reinforcing the interest in studying this northern part of Africa. The recent development of numerous dating methods has made it possible to reinforce and consolidate the chronostratigraphic framework, which for many years had been based solely on radiocarbon dating. These methods have sometimes even contributed to the confirmation of ‘new’ ideas that have dusted off the existing framework of prehistory. This article presents a chronology of the main ancient sites of the Maghreb dated by different methods whose ages compared to the results obtained by other disciplines participate and contribute to a better understanding of the environmental and cultural framework of prehistoric Man.     

Les faunes d'ammonites du Carixien inférieur et moyen du gisement des Cottards (Cher)

The study of the traditional Cottard layer forthe first time allows the exact succession of lower and middle Carixian ammonites to be established.The most striking fact is the evolution of the Tropidoceras-Acanthopleuroceras lineage, a regular modification of the ribbing density and L¹ structure, an iterative variation of section and tuberculization.Precisions are given on Polymorphites and Beaniceras and three new species are described: Polymorphites evolutus, Beaniceras cottardiense, Acanthopleuroceras alisiense.     

Associations de kystes de dinoflagellés des séries du Jurassique supérieur (Oxfordien–Tithonien) du Rif externe (Prérif interne et Mésorif,Maroc) et comparaisons régionales

A biostratigraphic study of dinoflagellate cysts of the Upper Jurassic series from the eastern External Rif Chain, has been achieved for the first time on four outcrop sections : the DM section (Douar Marticha), the TB section (the Tarhchenna “Sof”), the KSD section (the Kef Mallou “Sof”) and the Y section (Douar Lamriene) among which three sections (TB, KSD and Y) are well-dated by ammonites and calpionellids fauna. The DM and TB sections are complementary in terms of stratigraphy and correspond respectively to the upper part of the “Ferrysch” Formation, a thick shaly–silty and sandy sequence assigned to the Callovian-Oxfordian stages and to the El Gouzat limestones Formation (Kimmeridgian - Lower Tithonian age) and to the Tarhchenna marly limestones Formation (Upper Tithonian age) from the EL Gouzat area (Mesorif). The KSD and Y sections are also complementary and correspond to the Kimmeridgian-Lower Tithonian Msila limestones Formation and to the overlying marly limestones Massif Formation of Upper Tithonian age, outcropping in the Msila region (Internal Prerif). These four sections have shown many dinocysts rich levels, which had allowed characterizing the Middle? and Upper Oxfordian substages in the DM section. In the other sections, the dinoflagellate cyst assemblages are nearly similar to those of the Kimmeridgian–Tithonian of many sections from the Boreal, Sub-boreal and North tethyan realms, particularily from England, Russia and South-East France basin. The results of the present work confirm once again, the important value of dinoflagellate cysts, for age dating of ammonites-lacking Mesozoic sedimentary sequences and for biostratigraphic correlations.     

Biostratigraphie des Miospores et des Chitinozoaires du Silurien supérieur et du Dévonien dans le bassin d'Illizi (S.E. du Sahara algérien)

Core samples from the Illizi basin yielded well preservedmiospores and Chitinozoa. The detailed study of the range of these microfossils allows accurate age assignment for upper Silurian and Devonian subsurface strata of the southeastern part of the algerian Sahara. On the other hand, these biostratigraphical data demonstrate the occurrence of important stratigraphical gaps related to recurrent emersions.