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International audience; A re-examination of the historical collections deposited at the Bordeaux Museum of Natural History and the Faculty of Sciences of the University of Bordeaux made it possible to identify new taxa of Modulidae in the Oligocene and Miocene of the Aquitaine Basin. These Modulidae belong to the American groups Modulus modulus and Trochomodulus. In addition, three new species are described: Modulus benoisti sp. nov. (Serravallian), Trochomodulus stampinicus sp. nov. (Rupelian), which is close to Trochomodulus sublaevigatus (Orbigny, 1852), a Chattian species, and Incisilabium trochiformis sp. nov. (Priabonian). The latter is the oldest known Modulidae, together with Incisilabium parisiensis (Deshayes, 1832) (Middle Eocene) that was previously classified in the Trochidae. These results show that the paleobiogeography and origin of the family Modulidae need to be reconsidered.; L'examen de collections historiques déposées au Muséum d'Histoire Naturelle de Bordeaux et à la Faculté des Sciences de l'Université de Bordeaux a permis d'identifier de nouveaux taxons de Modulidae dans l'Oligocène et le Miocène du bassin aquitain. Ces Modulidae appartiennent aux groupes américains Modulus modulus et Trochomodulus. Trois nouvelles espèces sont décrites : Modulus benoisti nov. sp. (Serravallien), Trochomodulus stampinicus nov. sp. (Rupélien), proche de Trochomodulus sublaevigatus (Orbigny, 1852), une espèce chattienne, et Incisilabium trochiformis nov. sp. (Priabonien). Ce dernier est le plus ancien Modulidae connu avec Incisilabium parisiensis (Deshayes, 1832) (Éocène moyen) précédemment classé dans les Trochidae. Ces résultats montrent que la paléobiogéographie et l'origine de la famille des Modulidae doivent être réexaminées.

Benthonella, one of the most characteristic genera of the abyssal fauna, has a fossil history reaching back to the Lower Eocene. The five species recognized in the Paleogene of the Aquitaine Basin hav

Biodiversity estimates through geological times are difficult because of taphonomic per- turbations that affect sedimentary records. Pristine shell assemblages, however, allow for calibration of past diversity. Diversity structures of two exceptionally preserved Miocene bivalve assemblages are quantitatively determined, compared with recent communities and used as paleoenvironmen- tal proxy. The extremely rich assemblages were collected in Aquitanian (Early Miocene) carbonate sands of the Vives Quarry (Meilhan, SW France). Both paleontological and sedimentological data indicate a coral patch-reef environment, which deposits were affected by transport processes. Among two samples more than 28.000 shells were counted and 135 species identified. Sample Vives 1 is in- terpreted as a proximal debris flow and Sample Vives 2 as a sandy shoreface/foreshore environment influenced by storms. The two Vives assemblages have a similar diversity structure despite facies differences. Rarefaction curves level off at ~600 shells. The rare species account for more than 80 % of the species pool. The high values of PIE diversity index suggest a relatively high species richness and an even distribution of abundance of the most common species within the assemblages. The fossil data are compared to death shell assemblages (family level) of a modern reefal setting (Touho area, New Caledonia). The shape of the rarefaction curves and PIE indices of Meilhan fossil assemblages compare well to modern data, especially those of deep (>10 m water depth), sandy depo- sitional environments found downward the reef slope (slope and pass settings). In addition to primary ecological signals, the similarity of the Vives samples and the Recent deep samples derives from taphonomic processes. This assumption is supported by sedimentological and paleontological obser- vations. Sediment transports gather allochthonous and in situ materials leading to mixing of various ecological niches. Such taphonomic processes are recorded in the diversity metrics. Environmental mixing and time-averaging of the shell assemblages disturb the preservation of local-scale diversity properties but favour the sampling of the regional-scale diversity.

A new species of the genus Epiphaxum (family Lithotelestidae) is described and illustrated in detail, and compared to other species. Epiphaxum arbuscula sp. nov. has been collected from Upper Eocene (Priabonian), Upper Oligocene (Chattian) and Lower Miocene (Upper Burdigalian) deposits of the Aquitaine Basin, south-west France. Epiphaxum is a poorly documented genus but its fossil record extends back to the Late Cretaceous; it was previously known only from the Paleocene (Danian). Epiphaxum arbuscula differs from all others species of the genus in the form of its colony. In contrast to the creeping colonies of previously known species, it has branched colonies. It is very common at one Upper Oligocene outcrop from which an assemblage with submarine cave remains has been described. A close relationship between the three extant species (two from the Caribbean Sea and one from the Indo-West Pacific region) and the Paleogene species is also noted. These constitute a group that has not undergone any important morphological changes for the last 65 million years.

The West Indian Top-shell, Cittarium pica (Linnaeus, 1758), is a very classic and common species of the Caribbean faunal province. Until now the only known fossil occurrence of Cittarium pica , and of the genus Cittarium , is from Pleistocene deposits restricted to the Caribbean province (Clench and Abbott, 1943). Despite the turbiniform shell, the monotypic genus Cittarium belongs to the family Trochidae and was assigned to the tribe Gibbilini Stoliczka, 1868 by Hickman and McLean (1990). This paper reports a new species of Cittarium and the only record outside the Caribbean province. More than twenty million years separate the single modern species of Cittarium and the new fossil species. All material collected is deposited in Museum national d'Histoire Naturelle, Paris (MNHN). The five Cittarium specimens from the Upper Oligocene were collected during extensive field work on the Oligocene and Miocene faunas of Aquitaine (southwestern France). The outcrop where they were discovered is located near Dax and St-Paul-les-Dax (Landes). In Aquitaine, Upper Oligocene deposits are accessible as outcrops only in the Adour basin situated in the southwestern part. These deposits were correlated with the calcareous nannofossil zones NP 24 and NP 25 (Cahuzac et al., 1995). They are transgressive and have been deposited after a major regression at the Rupelian (Stampian)/Chattian boundary. In the southern part of the Adour Basin, Kieken (1973) revealed a deeply incised submarine canyon, the “Paleocanyon of Saubrigues,” which is probably related to this major sea-level fall. The canyon was partially filled by Upper Oligocene deposits. The Upper Oligocene deposits of the Adour basin contain a very rich mollusk fauna (about 1,600 species) which, partially, fills an important gap in our knowledge of the Cenozoic European fauna. This fauna is currently being described and comprises numerous new records of fossil genera (Lozouet, 2000). Classic …

A sedimentary deposit discovered at Kerguelen Islands in 1988 is interbedded in the Cape MacLear cliffs, near Mont Rond (Ronarc'h Peninsula). The age of this oceanic deposit is considered to be lower to middle Miocene as indicated by isotopic dating of both the underlying and overlying basalts. This deposit yields a fauna essentially consisting of molluscs (bivalves, gastropods) and crustaceans (cirripedes). This fauna exhibits some similarities to Miocene to Recent austral faunas (New Zealand, Argentina) as a result of the establishment of the Antarctic Circumpolar Current. However, it has no species in common with the extant Kerguelen fauna. The Mont Rond fossil assemblage is best compared with either of two types of extant communities developed on a bare sandy sea floor where infaunal species are dominant, but most likely to an opportunistic one in depths from approximately 10 to 80 m.

A general overview of the biodiversity of the marine fauna during the Tertiary period is developed in the context of the biogeographical evolution of the European realm. This study combines a reappraisal of the literature with a unique first-hand source of data on the richest marine group (the gastropods) from over a 25 million year period (Early Oligocene to Late Miocene). In total the French deposits have yielded more than 10,000 species from the Eocene to the Upper Miocene. Evidence of significant bias in the fossil record is pointed out for the Palaeocene (Danian) and Upper Eocene (Priabonian). For the period considered (Palaeocene to Late Miocene, ca 50 million years) the second highest diversity is reported in the Late Oligocene. This study reveals also the importance of pre-Miocene extinctions of genera. The Oligocene was when the latitudinal differentiation of the faunas was greatest. The local generic gastropod richness ranges from 59 (Rupelian of Belgium) to 494 (Chattian of Aquitaine). A clear trend towards homogenization appears in the Late Oligocene which leads to the development of a vast biogeographical region named Euro-West Africa. This faunal evolutionary pattern has never been demonstrated before and is a novel feature of the biogeography of the Eastern-Atlantic region.

Pyramidelloides dolini n. sp., older strongly sculptured eulimid, is described from the Middle Eocene of southwestern Alabama (Gosport Sand). This new species probably had a planktotrophic larval stage similar to the recent Indo-West-Pacific species. Relationship with the species of the genus Palisadia is discussed. Geographic distributions of both the fossil and the recent species of the genera Pyramidelloides and Palisadia support finally a classic pattern in tropical marine biogeography: a discontinuous geographic range between Indo-Pacific and Caribbean provinces.

Resume La stratigraphie des series marines oligo-miocenes du bassin de Sivas est revisee sur la base de faunes et microfaunes planctoniques et benthiques. Dans la region de Sivas, a trois des principales unites structurales correspondent trois series lithostratigraphiques differentes, caracterisant autant de paleoenvironnements allant du marin franc de bassin a une plate-forme coralligene et a une lagune bordant des zones emergees. L'âge oligocene du gypse massif qui sert de soubassement a ces series se trouve ainsi confirme. Des series continentales de meme âge, situees a l'ouest et au sud de Sivas, rendent les relations directes avec la Mediterranee orientale plus difficiles a interpreter.

Brachiopods from the Upper Oligocene (Chattian), Aquitaine Basin, southwestern France comprise nine species in seven genera: Novocrania Lee & Brunton, 2001, Terebratulina d'Orbigny, 1847, Megathiris d'Orbigny, 1847, Argyrotheca Dall, 1900, Joania Alvarez, Brunton & Long, 2008, Megerlia King, 1850, and Lacazella Munier-Chalmas, 1880. One megathyridid is described as a new species, Joania peyrerensis n. sp., characterized by ornamentation of 6–8 distinct, sharp ribs and by triangular, plate-like teeth. With the exception of Megathiris detruncata (Gmelin, 1791) and Lacazella mediterranea (Risso, 1826), all species are recorded for the first time from the Oligocene of the Aquitaine Basin. In taxonomic composition this brachiopod fauna displays close affinity with the Miocene faunas of the Mediterranean Province and Central Paratethys. The dominance of micromorphic megathyridids and thecideides in the Peyrere assemblage, characteristic of cryptic habitats suggests the presence of submarine caves and/o...

De nouvelles études morphostratigraphiques et biostratigraphiques ainsi que des datations ont été entreprises sur le célèbre dépôt de tuf calcaire de La Celle-sur-Seine afin d'obtenir une reconstruction détaillée des successions paléoenvironnementales et climatiques enregistrées dans cette formation interglaciaire du Pléistocène moyen. L'approche développée a privilégié l'aspect pluridisciplinaire afin d'exploiter la richesse paléontologique du gisement, de mieux appréhender ses caractères morphostratigraphiques et de préciser sa position chronologique. Les premiers résultats obtenus à partir des études malacologiques montrent que le dépôt, composé de tufs et de niveaux limono-argileux, s'est construit en progradant le long du versant. Ainsi l'épaisseur totale de la formation atteint près de 9 mètres. Les malacofaunes permettent de reconstituer une évolution paléoenvironnementale correspondant au début puis à l'optimum d'une phase climatique interglaciaire. Les niveaux sommitaux sont, eux, caractérisés par un net recul de la couverture forestière.La création de nouveaux profils stratigraphiques a permis la découverte dans un niveau de limon gris tufacé d'une abondante faune de mammifères accompagnée par quelques silex taillés. Cet horizon appartient à la malacozone la plus riche en taxons thermophiles qui est interprétée comme la phase optimum de l'Interglaciaire. La signification environnementale et climatique du cortège mammalogique, qui comprend en particulier de l'hippopotame et du macaque, corrobore les résultats malacologiques. L'industrie lithique est de type bifaciale en cohérence avec les récoltes de bifaces acheuléens effectuées à la fin du 19ème siècle. La composition du cortège de mollusques permet de rapprocher la faune de La Celle de "l'assemblage à Lyrodiscus", caractéristique des tufs du stade 11 dans le nord-ouest de l'Europe. Cette attribution chronologique est confirmée par les premières mesures radiométriques obtenus par U-Th sur des échantillons de tuf induré et par RPE/U-Th sur une dent de cheval. Enfin la révision des collections paléontologiques d'empreintes foliaires permet, en conjonction avec les données malacologiques, d'initier la discussion sur l'interprétation paléoclimatique du biome à Lyrodiscus. L'association floristique et faunique de La Celle qui comprend quelques taxons arboréens méditerranéens et nombre de gastéropodes éteints ou de répartition actuelle centre-européenne et océanique rend compte d'un environnement tempéré de forêt humide. La présence de ces espèces allochtones dans le nord de la France est mise en parallèle avec la durée exceptionnellement longue du Stade Isotopique Marin (SIM) 11 et de faibles amplitudes de températures saisonnières, qui auraient permis à plusieurs taxons méridionaux de coloniser cette zone septentrionale, plutôt qu'avec un climat plus tempéré que l'actuel. New morpho and biostratigraphical studies have been undertaken at the famous calcareous tufa deposit of La Celle-sur-Seine in order to obtain a detailed paleoenvironmental and climatic reconstruction from this Middle Pleistocene Interglacial formation. Multiproxy approach allows to study palaeontological contain of the tufa as well as its morphostratigraphical aspects and chronological allocation. First results from malacological study show that the tufa edificated downwards the slope reaching a total thickness of 9 metres high. Moreover molluscs show palaeoenvironmental succession corresponding to the early part of an Interglacial period followed by an optimum phase. Finally, at the top of the deposit faunas clearly indicate decrease of forest biotopes.Excavation of new profiles have allowed to discover a grey silty tufa horizon (lgt) yielding abundant mammal remains and a few lithic artefacts. This level is part of the molluscs zone 3 corresponding to the climatic optimum. Palaeoenvironmental and climatic conditions inferred from mammal assemblage (including Hippopotamus and Macaca) strengthened the malacological interpretation. The lithic industry is identified as Acheulean and appears in agreement with earliest handaxes discoveries during the late 19th century.La Celle malacological fauna belongs to the well-known MIS 11 "Lyrodiscus assemblage" in north-west Europe. This chronological allocation is confirmed by first U-series radiometric measures. Finally reappraisal of leaf print collections allows together with malacological data to discuss palaeoclimatic interpretation of the "Lyrodiscus biome". Flora and fauna from La Celle include a few mediterranean trees and several extinct gastropods together with few molluscs of central Europe modern range, allowing to describe a forest and humid lanscape. Presence of these peculiar species in northern France is thought to be related with the long length of MIS 11 and lower seasonal temperature contrast, that have allowed northern colonisation by southern species, rather than with occurrence of temperature higher than today.