L’impact de l’environnement sur l’évolution biologique et culturelle dans les périodes de transition en Préhistoire : Paléolithique ancien/moyen et Paléolithique moyen/supérieur

This paper deals with the environmental changes during two important transitional periods, namely Lower/Middle Paleolithic and Middle/Upper Paleolithic transitions, and with their impact on biological and cultural evolutions, in the context of central, eastern and northwestern Europe, where ice-sheet transgressions induced particular paleogeographical and paleoecological conditions. Another country was studied too, the Balkans, a privileged area for bilateral contacts between Europe and the Near East.     

Réflexion sur la coexistence de flores hygrophile,mésophile et mésoxérophile durant le Paléozoïque Supérieur en Euramérie

At the end of Namurian A, in Eurameria, we see agreat change in the composition of the flora, probably instigated by a great modification in the climatic conditions. This flora adapted to very humid places persist during whole the Westphalian and up to the end of Stephanian where it is relayed by a mesoxerophytic flora of which the most typical elements are the Coniferales of the family Lebachiaceae. This «autunian flora is usualy considered as subsequent to the stephanian hygrophytic flora and as the transition to the permian flora which is determined by a new modification of the general climatic conditions.Some observations about the macroflora and about the microflora lead to prove the coexistence of hygrophytic, mesophytic and mesoxerophytic floras, not only during the upper Stephanian but also during Westphalian and Namurian B and C. So, from Devonian to Permian, in Eurameria, there was probably continuity of a mesoxerophytic and mesophytic type floras on which was superimposed during the upper Carboniferous an hygrophytic flora adapted to the swamps surrounding the coal-lakes and coal-lagoon. The time of the appearance of Coniferales is older as we think usually.     

Neanderthal mobility and technological change in the northeastern of the Iberian Peninsula: The patterns of chert exploitation at the Abric Romaní rock-shelter

Understanding the changes in the technological organization of prehistoric hunter–gatherers is important to research into hominin foraging activities. During the Middle Paleolithic, the coexistence or the replacement between Levallois and discoid technologies has frequently been recorded, but there is still no clear understanding of the reasons for their alternating and fragmented use in the archaeological record. This paper aims to contribute with new data to the current debate, by exploring the chert assemblages from levels O and M of the Abric Romaní rock-shelter. The results reveal that the change from Levallois in level O to discoid in level M is accompanied by the use of different axes of mobility, a reduction in the foraging radius and a more careful management of raw materials. A cross comparison with other archaeological evidences indicates the general pattern in the Northeast of the Iberian Peninsula during the late Middle Paleolithic, in which the use of Levallois technology is associated with chert and high mobility patterns whereas discoid technology is more closely linked to the use of local raw materials and a lower degree of mobility. The modifications to the mountainous environments and to the distribution of preferred prey animals may have influenced the Neanderthals’ mobility patterns and contributed to modifying their technical behaviours in order to obtain better foraging incomes.     

Exploring Neanderthal skills and lithic economy. The implication of a refitted Discoid reduction sequence reconstructed using 3D virtual analysis

Lithic refitting studies have consistently contributed to address two specific research aims: the intra-site mobility and identification of preferential areas or latent structures, and the in-depth analysis of the knapping technologies and core reduction strategies. Multiple refits, in particular, can produce highly detailed data on knapped stone technology. Elucidating human skills and lithic economy, a potential still rarely evaluated for Discoid technology: a stone knapping method largely spread across the Middle Paleolithic of Europe. The opportunity to explore Neanderthal knapping behavior is provided from the remarkable discovery of a primary lithic waste concentration in the Mousterian Discoid level of the Grotta di Fumane, Italy, dated to at least 47.6 ky cal BP. With a combined approach that included the 3D virtual interaction, we were able to reproduce a complete reduction sequence that supports the technological analysis conducted on the lithic assemblage. Results lead to a better comprehension of the knapper's technological and technical behavior, including the detection and quantification of economic objectives and productivity.     

Chronostratigraphy and the Palaeoenvironment of the Bistrița Valley. New Interpretations and a Critical Retrospective Evaluation

The Carpathian Arch was certainly a difficult obstacle for the Palaeolithic communities of Eastern and Central Europe, at least during certain stages of the Upper Pleistocene glaciation, such as the Last Glacial Maximum. The density and perennity of the Palaeolithic occupations in the Bistri?a Valley were favoured by the propitious conditions of living and developing long-term survival strategies. The importance of the Bistri?a Valley lies in the fact that it is strongly embedded in the mountainous landscape, with a route extended in the Sub-Carpathian area and a generous opening towards the east to the plateau region and further towards the Great Russian Plain. The Bistri?a Valley is a landmark of the Romanian Palaeolithic due to the number of investigated Palaeolithic settlements, the wealth and variety of archaeological materials and the extensive interdisciplinary studies. All this has entailed a better assessment of the evolution of the palaeoenvironment and of the chronostratigraphy of the Palaeolithic occupations. In a matter of speaking, the Bistri?a Valley is to Romania what the Vézère Valley is to the Dordogne region in France.     

The evolution of the Brachycytheride Ostracoda in the context of the breakup of Pangea

The ostracode Family Brachycytheridae is one of the most common taxa of Late Cretaceous shallow marine microfossils, and occurs in the marginal basins of Africa, Madagascar, the Middle East, South and North America and the Caribbean region. Their migration pathways were controlled largely by the plate tectonic events associated with the breakup of Pangea and the formation of the North and South Atlantic Oceans, the Caribbean Sea and the Gulf of Mexico. This study is an attempt to combine specific information on the plate tectonic events as evidenced by the timings of continental-scale structural movements, sea level dynamics (largely the product of mantle processes), the creation and destruction of migration pathways, and taxonomy of the group, and thus relate deep-seated Earth processes, surficial expression of these movements, and biological evolution. Although the Late Cretaceous Brachycytheridae are very widely distributed, their use for correlation has been hampered due to their conservative external morphology, with all of them having a posteriorly-sloped dorsal margin and a swollen ventrolateral carapace, and all of them were long assigned to a single genus, Brachycythere. In 2002, Puckett defined a new genus, Acuminobrachycythere, based on a distinctive clade of North American brachycytherids. It was also recognized at that time that the members of the family from Gondwana (mainly Africa and South America) were distinct in having a single (unsplit) second adductor muscle scar, whereas all of those from North America had a split second adductor. This tiny difference holds significant paleogeographic—and presumably evolutionary—information. Two new genera are therefore described herein, Sapucariella, which is restricted to Gondwana, and Tricostabrachycythere, which is an early, short-lived genus that occurred around the margins of Gondwana. Three new species are described and one is re-described. In all, there are six genera in the Family Brachycytheridae, which include Acuminobrachycythere, Brachycythere, Kaesleria (which is restricted to the Middle East), Opimocythere (which evolved in the Paleogene of North America and is the last of the Brachycytheridae), Sapucariella and Tricostabrachycythere. Taxonomic information is presented for 85 species, including new images of many of the type specimens. A summary of the breakup of Pangea is also presented, with precise paleogeographic reconstructions based on global magnetic anomalies.     

Before the transition? The final middle Palaeolithic lithic industry from the Grotte du Renne (layer XI) at Arcy-sur-Cure (Burgundy,France)

The Grotte du Renne at Arcy-sur-Cure (Burgundy, France) has yielded remains from several occupation layers, extending from the end of the middle Palaeolithic to the upper Palaeolithic. The last Mousterian layer (XI), which precedes the Châtelperronian occupations (layers Xa, Xb, Xc, IX, VIII), was previously interpreted as a precursor of the transition complex. The new study of the lithic assemblage of layer XI, in the context of the other final Mousterian occupations in Arcy (Grotte du Bison, Galerie Schoepflin Rotonde, Grotte de l’Hyène) challenges this hypothesis. The Mousterian Arcy complex can be divided into three main techno-complexes: Levallois–Charentian, Discoid–Denticulate and Levallois Mousterian. We observed a rupture between the final Mousterian and Châtelperronian industries as regards all the aspects of the technical system; production methods, blank management, tool types, and some changes in raw material composition.     

Primary structure of the two (4 Fe-4 S) clusters ferredoxin from Desulfovibrio desulfuricans (strain Norway 4)

The primary structure of a ferredoxin isolated from D. desulfuricans Norway strain, which we called ferredoxin II (Fd II) has been elucidated. This ferredoxin is a dimer constituted of two identical subunits of molecular weight 6000. In ferredoxin II two (4 Fe-4 S) centers are present per subunit instead of one (Fe-S) center as is the case for the other ferredoxins isolated from Desulfovibrio and for Fd I from the same organism. The comparison of amino-acid sequences shows that ferredoxin II presents more homologies with clostridial type ferredoxin than with the ferredoxins from D. gigas and D. africanus.