Candoninae trapézoïdales (Crustacea, Ostracoda) du Bassin de Turiec (Slovaquie) du Miocène supérieur : systématique, écologie et évolution

The trapezoidal Candoninae from the Turiec Basin in Slovakia referred to the Candona sitari- and to C. aculeata-groups have characters that contrast with the valves of the Recent central European Candonines. The particularities concern the degree of calcification, the zone of concrescence, the overlap, and the presence of protuberances, the dorsum and the tubercles. Within the sitari-group, these characters evolve simultaneously with rapid evolution of the valve outline from subtrapezoidal to trapezoidal in shape. The species of this group acquire valve contours similar to those of the trapezoidal Candoninae of the Lake Pannon and the recent fauna of the long-lived lakes. The trapezoidal Candoninae of the Turiec Basin are associated with candonines that have triangular and rectangular carapaces with a pointed posteroventral margin. These three morphotypes indicate relatively stable habitats with weak environmental fluctuations. The trapezoidal species are rare in the littoral facies in both the north and the marginal areas of the Turiec Basin, but very abundant in the centre and south of the Basin. They probably lived in a profundal environment and their evolution probably occurred in relation to both sexual reproduction and a benthonic mode of life. The two groups comprise 18 species, of which 15 are described as new.     

Cyprididae (Ostracoda) du Miocène supérieur du Bassin de Turiec (Slovaquie) : Taxonomie et Paléoécologie

Twelve species of the family Cyprididae were found in the Upper Miocene of the Turiec Basin, of which three are new - Herpetocypris denticulata nov. sp., H. pusilla nov. sp. et Psychrodromus janzi nov. sp. The occurrence of Mediocypris suggests that ostracods occupied the Turiec Basin since the Middle Miocene. The psychrophilic genera (Psychrodromus and Cavernocypris) provide evidence of cold springs around the lake. In the sediments studied, the Cyprididae are associated with other ostracods that characterise shallow aquatic habitats and a diverse community of both aquatic and terrestrial plants. The sexual paleo-populations of Heterocypris salina (Brady, 1868), Herpetocypris pusilla nov. sp. and Psychrodromus janzi nov. sp. are observed.     

Euxinocythere (Ostracoda, Cytheridae, Leptocytherinae) du Miocène supérieur du Bassin de Turiec (Slovaquie) : taxonomie et paléoécologie

Eight new species of the family Cytheridae have been identified in the Upper Miocene deposits of the Turiec Basin (Slovakia), a small isolated intermountain depression. Six species are new - Euxinocythere aphroditae, E. delicata, E. lactea, E. minuscula, E. quadricostata, E. satyrica - and two are kept in open nomenclature. Their attribution to the genus Euxinocythere is based on arrangement of the hinge elements and of anterior marginal zone. This genus is known from brackish ostracod assemblages of the Paratethys and the Eastern Mediterranean while the species from the Turiec Basin are associated to fresh-water assemblages. The Euxinocythere have been found in littoral as well in deep limnic environment.     

La phalange distale du pouce d’Orrorin tugenensis (Miocène supérieur du Kenya)

The lion's share of articles dealing with the thumb anatomy of Plio-Pleistocene hominids has focussed on the capacity to manipulate and manufacture tools, and has largely neglected the locomotor aspects. However, in these hominids, the forelimb was still employed in locomotion. Certain of the anatomical characters classically associated with manipulation and/or fabrication of tools are already present in the Late Miocene species Orrorin tugenensis as shown by the terminal thumb phalanx BAR 1901'01. This specimen reveals crucial information suggesting that thumb morphology is not exclusively related to such tool using and manufacturing activities but reflects in a frequently bipedal creature a deeper adaptation concerning the precision grip essential for climbing and balancing, different from that of apes.     

Un nouveau Bovini dans la faune du Pléistocène supérieur d’Algérie

During the study of the Quaternary Maghrebian bovines in 1985, the review of the Bovini (aurochs and buffalos) found in Upper Pleistocene sites of Algeria showed that in comparison with most of the African bovine assemblage the attribution of genus Pelorovis to the species antiquus was inappropriate. The biometric and cladistic data revealed a close kinship with genus Syncerus. Later, other authors’conclusions confirmed its relevance. The antique buffalo of the Aterian site of the Phacochoeri has all the characteristics of genus Syncerus, but is different in that it shows a certain number of specific characteristics described in this article.     

Échinodermes de l'Ordovicien supérieur (Ashgill) de Sardaigne et d'Algérie

Research on the influence of sea level variations on the benthic faunas have been carried out in the Upper Ordovician of Sardinia. Study of the depositional facies and sequence analysis of the upper part (Lower Ashgill) of the Portixeddu Formation led to the identification of the sedimentary environments. Cystoids and crinoids are associated to bryozoans and brachiopods in most levels. The numerical analysis of associations and megaguilds shows that crinoids and cystoids have a higher frequency in the proximal and median facies of the upper offshore. The columnal association characterized by Conspectocrinus celticus and the coronoid Mespilocystites tregarvanicus has been discovered in the upper part of the formation. This material and complementary samples from Upper Ordovician of Sardinia and Kabylia (Algeria) bring additional data on the systematic and show the wide distribution of this fauna outside of the Ibero-armorican domain. The distribution of this echinoderm association supports a palaeogeographical position of the Ibero-armorican domain and Sardinia within the north gondwanan margin during the Lower Palaeozoic.     

Sur l'origine du genre Microceratina Swanson, 1980 (Ostracoda, Eucytherurinae) et sa présence téthysienne dès le Jurassique supérieur

The discovery in the uppermost Jurassic of Lebanon of a species of the ostracod genus Microceratina Swanson, 1980 (Eucytherurinae), of which the oldest known species was until now of Maastrichtian age, confirms the Tethyan origin of this genus. Two new species are created: Microceratina bhannesensis nov. sp. from the Upper Jurassic (Kimmeridgian) of Lebanon, and Microceratina azazoulensis nov. sp. from the Cenomanian of Morocco. The genera Chapmanicytherura Weaver, 1982 and Erratacytheridea Herrig et al., 1997, are considered as probable junior synonyms of Microceratina. An exhaustive bibliographical analysis allowed to identifying several other Cretaceous species susceptible to be assigned to the genus Microceratina.     

Nouveaux gisements à rongeurs dans le Miocène moyen continental du Bassin d'Aït Kandoula (Maroc)

The Azdal section in the Aït Kandoula basin show a succession of four fossiliferous layers delivering micromammals particularly rodents are very abundant than the great mammals. Mellalomys kandoulati nov. sp. is described in the oldest layer of the section. Compared to the Middle Miocene fauna of North Africa all the species from different layers are not yet reach the evolutionary stage of those of Pataniak 6. The old level has an age similar to those of Beni Mellal. The magnetostratigraphic study allows to situating these fore layers in chron C5An.2n and C5AAn.     

Les grands mammifères du Villafranchien supérieur des travertins du Bassin de Denizli (Sud-Ouest Anatolie,Turquie)

The large mammals from travertine deposits in the Denizli basin include the following species: Archidiskodon meridionalis meridionalis, Equus cf. altidens s. l., E. cf. apolloniensis, Stephanorhinus cf. etruscus, Metacervoceros rhenanus, Cervalces (Libralces) ex gr. minor-gallicus, Palaeotragus sp., Bovinae gen. and sp. indet. This association resembles those from the late Villafranchian of Southern and Eastern Europe, and, to some extent, fromWestern Asia, and could be older than 1.2 Ma.     

Découverte de Thyrsoporella pseudoperplexa Granier et Braik, 2002 (algue dasycladale) dans le Kimméridgien inférieur du bassin d'Essaouira (marge atlantique marocaine)

A dasycladacean alga recently attributed to the species Thyrsoporella pseudoperplexa Granier and Braik 2002, has been discovered within the Jurassic sediments of the Atlantic domain. This alga, only found in the Tethysian domain, was identified in the Early Kimmeridgian sediments of the Essaouira basin (Morocco).     

Comparaison de l'expression de certains caractères crâniens sur les hominidés chinois du Pléistocène récent et de l'Holocène (grotte supérieure de Zhoukoudian, sites de Longxian et de Yanqing)

The human remains recovered from “Grotte supérieure de Zhoukoudian” are the best-preserved Late Pleistocene human fossils in East Asia. For decades, as the representative of the Late Pleistocene human in East Asia, the Upper Cave skulls have been playing important role in the research of origins of modern Mongoloids and American Indians. With the advance of the origin and evolution of modern humans, more attention has been paid to the details and the mechanisms for the late Pleistocene human evolution and the formation of modern human populations. Both the origin and diversification of modern humans have been stressed. Some studies further trigger the debaters on the Upper Cave Man concerning its evolutionary level and its role in the formation of modern human populations in East Asia. To further explore these problems, we examined and compared 12 non-metric features on the 3 Late Pleistocene Upper Cave skulls and 162 Holocene individuals earthed from two archaeological sites of North China (Longxian and Yanqing). Our results indicate that 8 on the 12 features have different expression patterns between Upper Cave Man and recent Chinese leading the authors to believe that more primitive expressions appeared on the Upper Cave Man than on recent Chinese populations. Based on these findings, some problems on the intragroup variation in Late Pleistocene and Holocene populations are discussed.     

La macrofaune du Pléistocène supérieur d’El Harhoura 2 (Témara, Maroc) : données préliminaires

The El Harhoura 2 cave is situated in the commune of El Harhoura in the Temara region (Morocco). The entrance faces west, towards the ocean, around 200 m away from the current shoreline and about 16 m above sea level. The stratigraphy has currently 11 levels numbered from top to bottom. Level 1 is attributed to the early Neolithic. The archaeological material from level 2 places it within the Upper Palaeolithic (Iberomaurusian). Levels 3 to 11 are assigned to the Middle Palaeolithic (Aterian). Since 1977, a surface of 37 m² has been excavated, yielding particularly abundant remains of a large mammal fauna study in this paper.     

Foraminifères benthiques complexes du Bathonien supérieur au Kimméridgien inférieur de la marge atlantique marocaine (« Bassin » d’Agadir) : stratigraphie et paléobiogéographie

The carbonate sediments of the Agadir Basin (Morocco) deposited during the Upper Bathonian-Lower Kimmeridgian p.p. interval are rich in agglutinated complex benthic foraminifera. The detailed inventory of several field-sections allows to identify and to describe these benthonic foraminifera, some of them being recorded for the first time in Morocco. They belong to the main genera Archaeosepta, Andersenolina, Praekurnubia, Pseudocyclammina, Everticyclammina, Alveosepta, Kurnubia, Parurgonina, Neokilianina, Labyrinthina and Rectocyclammina. The stratigraphic and paleobiogeographic distribution of these foraminifera seem to be related to the geodynamic events occurring on the Moroccan Atlantic margin during this time-interval. The stratigraphic distribution of the principal species is generally controlled by the occurrence of ammonites, brachiopods and of some foraminifera which are considered as good stratigraphic markers.     

Des Miliolacea aux Alveolinacea (grands foraminifères): la faune du Crétacé supérieur et du Tertiaire inférieur du Chiapas (S.E. Mexique)

Found in Chiapas (South-East of Mexico), Praealveolina michaudi nov. sp. and Chubbina jamaicensis (of Campanian-Maestrichtian age) are described, both evolved from Nummoloculina sp. while Raadshoovenia guatemalensis (upper Paleocene-lower Eocene) arises from Quinqueloculina. We precisely analyze and modelize the nepionic coiling during the evolutionary change from Miliolacea to Alveolinacea. During ontogenesis as well as during phylogenesis, quinqueloculine coiling progresses to streptospiral and then to planispiral chamber arrangement with the increase of volume of embryo and of chambers. Appearance of these large foraminifers are understood as a consequence of the rise of K-strategies in their mode of life, following the development of photosynthetic symbioses.     

Ostracodes du Cénomanien supérieur et du Turonien de la zone sous-pyrénéenne orientale (Corbières méridionales, SE France). Systématique, biostratigraphie, paléoécologie et paléobiogéographie

Thirty-four species of ostracodes are collected in the platform series of the Southern Corbières; two biostratigraphical assemblages, with 13 and 29 species, are respectively recognized in Cenomanian and Upper Turonian; palaeoecology is specified. At that time, the ostracode sub-province of South-West France, established on Southern Corbières, Aquitaine, Touraine-Poitou-Charentes region and Provence, is connected with Eastern and Northern regions and countries: Sub-alpines ranges, Paris Basin, Great Britain, Switzerland and Bohemia, and with the Iberian Peninsula, sub-province of North-Central Spain and Western Portuguese Basin. The crossing of the Tethys and the Atlantic Ocean is realized, in Turonian, by some rare species.     

Heterosteginapapyracea Seguenza du Miocène du Corridor Sud-Rifain (Maroc) : biométrie et particularités paléoécologiques

Biometric study of the inner features of Heterostegina specimens preserved in tortonian sediments of the oued Yhoudi member allows to confirm the presence of species Heterostegina papyracea Seguenza, 1880. Analysis of both large and small components of the foraminiferal assemblage in all examined samples establishes the dominant character of species Heterostegina papyracea Seguenza (more than 60% of total benthic foraminifera). The assemblage of small benthic foraminifera associated with the Heterostegina is different from that described from Recent sediments, as well as from Miocene sediments of Calabria and Spain. In order to explain this result, two hypotheses can be put forward: (1) the Tortonian Heterostegina from Morocco proliferated abundantly in very shallow environments in association with small foraminifera (i.e. abundant Ammonia beccarii). (2) Because of powerful tidal currents in the South Rifian Corridor, Heterostegina tests were probably transferred after death. This transfer could possibly be due to the narrowness of the South Rifian Corridor in the Early Late Tortonian and its position between the Atlantic and the Mediterranean. Similar cases foraminiferal displacements are also known from modern basins. This study illustrates the difficulties in reconstructing the paleogeography of the studied area and the importance of considering all available components of the assemblage.     

La Grotte des Félins, site paléolithique du Pléistocène supérieur à Dar Bouazza (Maroc)

In the continental sediments filling a cave that developed in Middle Pleistocene deposits near Casablanca, Morocco, a very rich mammal fauna from the last climatic cycle was discovered. It was associated with a Middle Palaeolithic poor and atypical lithic assemblage manufactured on blocks and pebbles. The lower fossiliferous layer contained abundant carbonized remains of felids. Unfortunately, the site was destroyed by quarrying before adequate excavations could be carried out.     

Enregistrement des fluctuations du niveau marin dans l’Holocène supérieur du lac Retba (Sénégal) par les foraminifères

A study of sea level fluctuation records based on foraminiferal assemblages was carried out for the first time in a sediment core taken at the Lac Retba edge. A total of 37 foraminifera species were collected along the core, among which most are known in the modern estuaries and lagoons of Senegal. A succession of four assemblages dominated by Ammonia parkinsoniana and A. tepida were identified; they correspond to different stages of evolution of the lake. The first association, at the base of the core, indicates a lagoon slightly opened to the sea and bordered with vegetation, under relatively humid climate. The second has the richest and most diversified microfauna with a high proportion of coastal, marine benthic and planktonic species (about 10%) that indicate a small coastal gulf bordered with mangroves. The third association is oligospecific and typical of a closed and hypersaline lagoon under a dry climate. The last association again contains coastal, marine benthic and scarce planktonic species (3%) indicating a change to a saltier and more open lagoon under dry climate. The disappearance of planktonic foraminifera at the top of the core indicates the closure of the lagoon. The biocenotic indicators are evidence for two marine intrusions that are referred to the Dakarian (3000 years B.P.) and Saint-Louisian (2140-680 years B.P.) stages of the Upper Holocene of the senegalo-mauritanian stratigraphic scale. Evidence of the Lac Retba closure since 680 years B. P. appears in the core by high reduction of foraminifers’ abundance and diversity absence of planktonic species, and salts precipitated at the bottom of the lake.     

Étude biostratigraphique et paléoenvironnementale des diatomées pyritisées de l'intervalle Paléocène supérieur-Éocène inférieur du sondage de Saint-Josse (France)

This paper presents the results of a biostratigraphic analysis of pyritized diatom assemblages in the Saint-Josse core (CC82) located in the northern part of the Paris basin (coordinates: X =555?000, Y =307?324 and Z =56.9 m). During the Paleocene-Eocene this locality was situated in a small bight of the North Sea Basin. The results are obtained from sediments of the Thanet and Mont-Bernon group equivalents belonging to the Paleocene-Eocene interval. Thirteen samples were studied and eleven contain pyritized diatoms. By epigenesis, the siliceous frustule of the diatom is changed into a pyritized skeleton with all the ornamentation very well preserved such as the velum, the areolae, the labiate processes, etc. Dispersive X-Ray analyses show this complete replacement of silica by pyrite. Another form of pyritization is crystallization of pyrite (in cubes, pyritohedrons, octahedrons, framboids) in internal cavities of the diatoms to produce internal moulds, also called steinkerns, which preserve the external morphology of the diatoms and some details such as the girdle. Despite pyritization, diatoms can often be recognized at the species level; brackish and marine species were observed but no fresh water specimens were encountered. Pyrite is easily altered into iron oxides. In outcrops, pyritized diatoms can be obscured or destroyed by oxidation. We have chosen borehole samples for this study to avoid the affects of weathering. Deposits from the Sorrus Unit (of the Thanet Group) have low abundances of pyritized diatoms (3 to 25 specimens per sample). This unit contains allochtonous diatom assemblages comprising Actinoptychussenarius, Coscinodiscus morsianus var. morsianus, and Coscinodiscus morsianus var. moelleri. Sample 34.31-34.45 from this unit is particularly interesting. It contains three specimens of Paralia siberica var. laevis, which is typical of an estuarine or littoral paleoenvironment, and corresponds to the more continental deposit of the Sorrus Unit. Seven samples, taken in the Argile de Saint-Aubin Unit (from the Mont-Bernon Group), contain more than 200 pyritized diatoms and between 9 to 16 different species per sample. A brackish assemblage (Actinoptychus senarius, Coscinodiscus commutatus and Stellarima microtrias) and a marine assemblage (C. morsianus var. morsianus, Coscinodiscus var. moelleri, Fenestrella antiqua, Odontellaheibergii, Rhizosolenia sp. 1 and Trinacria regina) are observed. The brackish assemblage expands in the upper part of the Saint-Aubin Unit indicating more widespread brackish paleoenvironmental conditions. Pyritized diatoms are important fossil markers in the Paris basin mainly when siliceous fossils (silicoflagellates or radiolarians) and others microfossils (foraminifers and dinoflagellates) are very poor or absent. Two diatom assemblages have been identified in the Saint-Josse borehole. The first assemblage D1, comprising C. morsianus var. moelleri (high occurrence), C. morsianus (a few) and T. regina (rare), is recorded in the Sorrus, La Calotterie, Bois Gorguette, Le Goulet and lower Saint-Aubin Units. The second assemblage D2, characterized by great abundance of F. antiqua and decreasing numbers of C. morsianus species, is found in the upper part of the Saint-Aubin Unit. These diatom assemblages can be correlated with other biozonations established in the North Sea basin and based on nannoplankton and diatoms (King, 1983), diatoms (Mitlehner, 1996) and calcareous nannoplankton (Martini, 1971). F. antiqua and C. morsianus var. moelleri are the more important diatom species encountered. F. antiqua (previously named Coscinodiscus sp. 1, King, 1983) is the fossil marker used by King to define his NSP4 biozone. The base of NSP4 corresponds to the lowest occurrence of F. antiqua and the top is marked by the highest occurrence of this species. The Sorrus, La Calotterie, Bois Gorguette, Le Goulet and Saint-Aubin (“Sparnacian” stage) Units, the last one comprising F. antiqua (increasing to acme), correspond to the NSP4 zone of King (1983). The Mont-Hulin and Château de la Bruyère Units correspond probably to the NSP5 zone of King (1983). F. antiqua and C. morsianus var. moelleri were also used by Mitlehner (1996) to differentiate the NSP4a zone (low abundance of F. antiqua and abundance of C. morsianus var. moelleri) from the NSP4b zone (great abundance and acme of F. antiqua). The abundance of C. morsianus var. moelleri is recorded in the lower part of Saint-Aubin Unit and the abundance of F. antiqua (high peak at 46% in the sample 17.87) is found in the upper part of Saint-Aubin Unit. Therefore, Sorrus, La Calotterie, Bois Gorguette, Le Goulet and the lower part of Saint-Aubin Units are correlated with the NSP4a zone and the upper part of Saint-Aubin Unit with the NSP4b zone. By correlating the calcareous nannoplankton biozonation (NP) of Martini (1971) with the biozonation of King (1983), adapted by Mitlehner (1996), the boundary between the NP9 and NP10 zones could be located in the 18.75-17.87 interval and the NP10-NP11 boundary at the top of Saint-Aubin Unit. Lithostratigraphic correlations between the units of the Saint-Josse borehole (Paris basin) and the formations of the North Sea basin can be established. The great abundance of C. morsianus var. moelleri and the great abundance (including acme) of F. antiqua are respectively recorded in the Sele and Balder Formations. Therefore, the interval Sorrus/lower Saint-Aubin Units is correlated with the Sele Formation and upper part of Saint-Aubin Unit with the Balder Formation.