Arvicolidae (Rodentia) from the Pliocene of Tollo de Chiclana (Granada, SE Spain)

Several new fossiliferous Pliocene localities have been identified in the continental deposits of the area of Tollo de Chiclana (Guadix Basin, SE Spain), that have yielded a rich rodent and insectivore fauna. In this paper, we study the Arvicolidae from these localities. Remains adscribed to the genera Dolomys, Mimomys and Kislangia have been found, which are very interesting from a biostratigraphical point of view.     

Le plus ancien hippopotame fossile (Hippopotamus laloumena) de Madagascar (Belobaka,Province de Mahajanga)

The Upper Pleistocene site Belobaka XVII (about 20,000 years) has yielded some Hippopotami remains included in a very hard breccia. Among this material two lower premolars, a juvenile calcaneus, two juvenile metatarsals and a first abaxial phalange have been cleaned and can be studied. They belong to Hippopotamus laloumena Faure and Guérin, 1990, allowed us to know for the first time the P/2 and P/3 of that species and confirm its validity. Belobaka is then the third Malagasyan site where H. laloumena has been found, and the first which yielded Pleistocene hippopotami remains.     

Papel de pituitary tumour-transforming gene (PTTG) en los adenomas hipofisarios

The pathogenesis of pituitary tumours is far to be understood. Pituitary transforming tumour gene (PTTG), a gen that induces aneuploidy, genetic instability, cellular proliferation and to stimulate angiogenesis, has been involved in neoplasic transformation and shown overexpressed in many neoplasm as lung, breast, endometrium, thyroid and colon malignant tumours. On the other hand, PTTG has been inconsistently studied in pituitary tumours. The majority of studies have been performed in animals and there is a great variability in the methods used in its determination. The goal of this review is to resume the role of PTTG in tumourogenesis and critically to revise the studies published in humans in order to advance in the knowledge of the pathogenesis of pituitary adenomas and to find clinical useful predictors of the behavior of these tumours.     

Étude chimiotaxonomique de deux espéces nouvelles de Hazunta (Apocynaceae)

Twenty-two indole alkaloids have been isolated from two new Hazunta species (Apocynaceae). Apparently, five of them are bis-indoles of a previously unknown structure.     

Les Ostracodes de la partie supérieure de la Formation deTeferguenite (Givétien) et de la Formation de Marhouma (Givétien-Famennien) de la coupe du km 30 (Saoura,Sahara algérien)

More than fifty ostracod species, twenty-two of which are Entomozoacea, have been identified in the upper part of the Teferguenite Formation and in the Marhouma Formation. The zonal sequence established on the Entomozoacea is applicable to the Frasnian and the Famennian of the Algerian Sahara; seven zones are recognized. One new species, Tubulibairdia marhoumaensis nov. sp., is described.     

Synthèse de trithioorthocarbonates de pyranosides par thermolyse de bis(dithiocarbonates)

The thermal decomposition of methyl 4,6-O-benzylidene-2,3-di-O-[(methylthio)-thiocarbonyl]-α-d-glucopyranoside afforded methyl 4,6-O-benzylidene-2-thio-α-d-mannopyranoside 3-O,2-S-(S,S-dimethyl trithioorthocarbonate) and methyl 4,6-O-benzylidene-3-thio-α-d-allopyranoside 2-O,3-S-(S,S-dimethyl trithioorthocarbonate) in good yield. This decomposition can be generalized to 1,3-diols derived from sugars. Thus methyl 2,3-di-O-methyl-4,6-di-O-[(methylthio)thiocarbonyl]-α-d-glucopyranoside afforded in the same way the corresponding trithioorthocarbonates, following a regioselective process. The structures of these trithioorthocarbonates are confirmed by spectral and chemical proofs.     

Etude de l'influence des facteurs visuels sur les comportements sexuels et agressifs de Mollienesia (Poecilia) velifera (Pisces,Poeciliidae)

One of the most striking features of cave fishes is their pronounced ocular regression. They are, however, perfectly adapted since they multiply and display the behaviour patterns which are biologically important in their surroundings. It is therefore of interest to study the relative role of visual factors in the corresponding behaviour patterns in related epigean species.Other authors have previously demonstrated the dominant role of chemical stimuli in the releasing of sexual behaviour patterns in M. sphenops, of which some forms are cavernicolous. In M. velifera and M. latipinna, on the contrary, visual factors seem more important. The releasers of the aggressive behaviour patterns of these three species seem to be predominantly visual. In the present study, the importance of visual factors has been verified experimentally in M. velifera by comparing the observed behavioural differences in experimentally blinded individuals and normal controls.The results of the pre-experimental phase show that there is no difference between these two groups before blinding, neither in the frequency of the patterns, nor in their numerical values.The results of the first experimental phase confirm the importance of visual releasers in the sexual behaviour patterns of M. velifera. Thus, sexual approaches, mouth—abdomen contacts and copulation attempts are totally absent in blinded pairs. Sexual motivation however is still present since the gonopodal flexions are equally frequent in both groups. On the other hand, it seems that aggressive behaviour patterns are maintained in blinded individuals but only when the partners are very close to each other or when an actual contact has taken place.The comparison of pairs in which only one of the partners is blinded (second experimental phase), as well as results of the first phase, suggest that experimental blinding does not cause hormonal changes liable to influence the observed patterns. In addition to this, the role of the ♀ in courtship has been specified. When a ♀ individual is intact and receptive, it will initiate courtship when it is placed in the company of an inactive blinded partner.     

Estudio paleoecológico de Foraminíferos de testigos del Holoceno de Golfo Nuevo (Patagonia, Argentina)

A micropaleontological study (Order Foraminiferida) was conducted on two Holocene cores from Golfo Nuevo (Patagonia, Argentina). The most abundant species are Buccellaperuviana f. campsi (Boltovskoy) and Bulimina patagonica (d’Orbigny), suggesting an inner-shelf environment. Qualitative and quantitative analyses indicate the paleoecological and paleoenvironmental variations along cores. A transition from normal marine conditions of the inner shelf during the Middle Holocene (ca. 8160-7700 years B.P.) to marginal marine conditions in the Late Holocene (ca. 1890 years B.P.) is inferred. This transition was accompanied by lower oxygen levels than the current values in Golfo Nuevo. These variations may have been due to an increase in precipitation near the study zone and a rise in sea level caused by an improvement in the climatic conditions related to the Climate Optimum (ca. 7000 years B.P.). These new conditions of higher temperature and lower salinity of the surface waters may have hindered deep-water renewal, producing a change in the circulation dynamics of the gulf and causing a reducing environment.     

In vitro: Régénération de plants de fraisier à partir de fragments de pétioles et de bourgeons floraux

Strawberry plants have been regenerated from petioles and flower buds Petiole segments derived from strawberry plants(Fragaria vesca L. andFragaria xananassa Duch. cvs. Gorella and Redgauntlet) maintainedin vitro have been cultured on the Gambobg’s. agar medium supplemented with 2,4-D (2 mg 1?¹) either alone or with kinetin or BAP (0.1 mg I?¹ or 1 mg I?¹). The calli thus obtained have been transferred to media differing from the first ones only by the nature and the concentration of the growth regulators used. One or two months later, shoots appeared on these calli. The influence of the media hormonal content on plant regeneration has been observed. Moreover, genotypic variations have also been investigated: the wild strawberry exhibited the greatest organogenic capacity. Shoots have also been obtained from flower buds(Fragaria xananassa Duch. cvs. Fern, Hummi Gento, Gorella and Redgauntlet). In this case, shoots appeared directly on small calli derived from the peduncular base of the flower buds. These regenerations have been observed, without changes of media, on the Lee and de Fossabd’s agar medium.     

Identification de C-glucosides flavoniques dans le genre Gentiana (section coelanthe)

Isoorientin, isovitexin, isoorientin-4′-O-glucoside and isovitexin-4′-O-glucoside have been identified in the leaves and roots of Gentiana punctata L., and in the leaves of G. purpurea L., G. pannonica Scop., G. villarsii Ronn., and G. burseri Lapeyr. Comparison with other gentians is discussed.     

Selaciens nouveaux de l'Albien superieur de Wissant (Pas-de-Calais)

Screening in the Albian of Wissant area has allowed to collect an interesting selachian fauna including some new elements: Orectoloboides nov. gen., Scyliorhinus destombesi nov. sp. and Protosqualus sigei nov. gen., nov. sp.. The relationships of these forms are discussed.     

Ostracodes turoniens de la region de Cassis,La,Bedoule (Bouches-du-Rhone,France): Associations et affinites paleogeographiques

The study of 15 species of ostracods from the Turonian of Provence is especially concernedin this paper; two new species are proposed: Mauritsina provencialis nov. sp. and Spinoleberis ectypus nov. sp.Two associations can have been recognized: one in the marly lower Turonian, theother in the zone of transition from the lower to the upper Turonian.These ostracods are replaced in the general stratigraphic context of the country and some comparisons can have been made with others countries.Some ecologic and paleogeographic remarks are proposed to contribute for a betterknowledge of the paleoenvironments.     

Les foraminifères du Burdigalien moyen à supérieur de la région sud-aquitaine (golfe de Saubrigues, SW France)

Many exposures assigned to the Miocene formation of “Marnes de Saubrigues” (southwestern Aquitaine Basin) have been studied. Their revised stratigraphical allocation has made it possible to recognize mainly Middle to Late Burdigalian age deposits which have been widely sampled. They have been correlated with planktonic zones N6 pars-N7 and NN3-NN4 and locally dated 17.7 Ma with Sr isotopes. It is noteworthy that this chronological interval is only known in the southern Basin. An inventory of the rather abundant microplankton is provided, including series crossed by drillings in the Gulf of Biscay. These deposits yield a large diversity of benthic foraminifera, nearly 400 taxa, which can be considered as a reference fauna for western Europe Burdigalian. From a geographic point of view, it has been possible to subdivise the exposures into groups according to their bathymetry. Let us point out the first discovery of Borelis in the Burdigalian of France and in the northeastern Atlantic Miocene as well. Very rare specimens of Cycloclypeus are also present in the Aquitaine Basin. Among smaller foraminifera, the occurrence of Rosalina aguayoi, Pavonitina styriaca, the last appearance of Falsocibicides aquitanicus and the persistance of the genus Almaena must be emphasized. Several assemblages supply diatoms, rare radiolaria and sometimes abundant sponge spicules; the presence of these organisms, seldom reported from the Aquitaine Tertiary, might be linked to upwelling-type currents. Bachmayerella (inc. sed.) is uncommon and cited for the first time in the Burdigalian. A few taxonomical remarks and short notes are given for some species of foraminifera, and palaeoecological details as well. Numerous taxa are represented and comparisons with the foraminifera faunas mainly from the Lower-Middle Miocene of Western Mediterranean and Paratethys are sketched.     

Alcaloïdes minoritaires de Capuronetta elegans (Apocynaceae)

Two monomeric and three dimeric new indole alkaloids derived from cleavamine have been isolated from the leaves and stem barks of Capuronetta elegans. Structural determination was made by physical and chemical correlations with the known major alkaloids of the plants.     

Un atoposauridé (Crocodylia,mesosuchia) du portlandien de la Meuse (est de la France)

A small crocodilian skull from the lower Portlandian (Cyrena rugosa beds) of Brauvilliers (Meuse) is referred to an atoposaurid of the genus Alligatorium, apparently closely related to the species A. paintenense from the Tithonian of Franconia. It is the first reportof one of these small continental crocodilians from north-eastern France.     

Un nouveau Cycloconchide (Mollusca Bivalvia) du Llanvirn inférieur (Ordovicien) des Monts de Tolède (Espagne)

A new Cycloconchid, designated Ananterodontaoretanica, has been collected from the Lower Llanvirn (Montes de Toledo). The only known specimen is described and compared with several genera of Ordovician Cycloconchids, the validity of which is briefly discussed.     

Révision d’Oryctolagus lacosti (Lagomorpha,Mammalia) du Pliocène supérieur de Perrier (Auvergne,France)

Fossil leporids from the Upper Pliocene of the locality of Perrier-Étouaires (Auvergne, France) are here revisited. They were initially attributed to Lepus lacosti by Pomel (1853), and later to the genus Oryctolagus. This material had been neither accurately described nor figured until now. Thus, a lectotype and two paralectotypes have been chosen among the material of the original collection. The diagnostic character of Oryctolagus lacosti is its big size, similar to that of modern hares (Lepus), together with other morphological characters that fit in the variability range of European rabbits (Oryctolagus cuniculus). Fossils of leporids similar to those of Perrier have also been found in several Plio-Pleistocene localities from western Europe.     

Sur des microfossiles calcaires problématiques du stratotype de la limite Campanien–Maastrichtien de Tercis (Sud-Ouest,France) : les gilianelles

Enigmatic calcareous microfossils are present in the stratotype section at Tercis, Landes, France (Campanian–Maastrichtian boundary). Thirty to thirty-five forms have been pictured and 1 to 100 specimens have been picked for each of them. The single-chambered tests show a small aperture. They present an axial symmetry, which is altered when radial equatorial expansions are added to the 75 to 200 μm-large bodies of discoidal, spheroidal, cupuliform, conical or barrel-like shapes. These peculiar characters are those of the gilianelles, a group of uncertain status created here. In addition to their palaeontological interest, these microfossils display a short time distribution and might have a stratigraphical interest. Gilianella stellata n. gn. n. sp. is described as a type form and illustrated.     

Nouveau matériel de Leptobos (Smertiobos) crassus (Artiodactyla, Mammalia) du Pléistocène inférieur à Renzidong (Chine de l’Est)

New remains of Leptobos (Smertiobos) crassus have been identified among the fossils excavated from a new early Pleistocene site at the Renzidong in Anhui Province, Eastern China. It is a Leptobos bearing frontal appendices with a simple curvature and its distal part turns higher than the other species of the subgenus. The present study shows that the first appearance of Leptobos in China is in the zone equivalent to the European MNQ 16b, later than its first appearance in Western Europe (MNQ 16a); and the genus Leptobos can serve as index fossil of the lower Pleistocene in China (2.5-0.78 Ma, Chinese definition).     

Conditions de digestion et activité de quelques polysaccharidases dans le tube digestif de l'oursin Paracentrotus lividus (Echinodermata)

The pH level of the gut fluid of the echinoid P. lividus is slightly acidic and its oxygen content is low (from 5 to 8%). An amylase and a cellulase-like enzyme are secreted by the echinoid stomach. Amylolytic activities have been detected also in food pellets from the stomach and from the posterior part of the intestine. This activity of intestinal pellets could be of microbial origin.