Nouvelles données sur le Magdalénien inférieur de la Région Cantabrique : le Niveau F de la grotte de El Cierro (Ribadesella,Asturies, Espagne)

El Cierro Cave (Ribadesella, Asturias, Spain), located near the mouth of the River Sella, has yielded one of the most important Upper Palaeolithic sequences in northern Spain. To date, three major occupation periods at the cave have been identified and dated. The first was at the beginning of the Holocene (ca. 8500 BP; ca. 9000 cal BP); the second at the end of the Upper Palaeolithic, in the Younger Dryas (YD) or Greenland Stadial 1 (GS1) (ca. 11.200 BP; 12.700 cal BP) and the third during Greenland Stadial 2 (GS2) (ca. 16.300–15.500 BP; ca. 19.200–18.700 cal BP). This paper describes the stratigraphy documented in the excavations performed by F. Jordá Cerdá and A. Gómez-Fuentes between 1977 and 1979 and presents the first radiocarbon determinations for the first two occupation periods, together with the study of the archaeological materials found in Level F. This level, dated to 15.500 BP (ca. 18.700 cal BP) is characterised by specialised red deer hunting and the gathering of marine resources (winkles). Various artefacts made from animal raw materials have been documented; both finished products and items in the process of being manufactured, as well as portable art objects. The lithic assemblage, consisting mainly of local raw materials with a small proportion of allochthonous flint, is characterised by an abundance of small bladelet cores and backed bladelets. These archaeological remains and the radiocarbon date mean Level F can be attributed to the so-called “Cantabrian Lower Magdalenian”. This period has been documented archaeologically and dated to a similar time at other sites in the River Sella valley and in the rest of northern Spain.     

Sur le développement abortif de certains embryons deLineus ruber (O.F. Müller) (Hétéronémertes)

Sommaire ChezLineus ruber on observe deux types de développement dans la même ponte: un développement normal et un développement abortif. Les ufs qui donnent des embryons normaux émettent deux globules polaires, les ufs qui donnent des embryons anormaux n'émettent qu'un globule polaire. Ils ne sont pas fécondés mais commencent à se diviser et arrivent tardivement au stade 16–32 blastomères, puis la segmentation s'arrête. On suggère l'existence d'une parthénogénèse abortive. Les facteurs du déclenchement du processus du développement abortif sont discutés.

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Abnormal development of some embryos of lineus ruber (O. F. Müller) (Heteronemertine)

Summary One can observe in the case ofLineus ruber, two types of development in the same egg string, a normal one and an abortive one. The eggs which give the normal embryos, give two polar bodies while the eggs which give the abnormal embryos, issue one polar body only, they are not fertilized but start to divide and belatedly reach the stade of 16–32 blastomeres.The existence of an abortive parthehogenesis is suggested and the mechanism of abnormal development is discussed.

     

Modalités d'installation et d'évolutiondes Harpocératinés (ammonitina A) au Domérien inférieur dans le sud-Ouest de l'Europe (France,Portugal)

In Mesogea, the Harpoceratinae were known asearly as the end of the Lower Carixian. They later reached the sub-boreal province through the Alps or the South of the Iberic Peninsula. The analysis of the populations met in four crosssections of the Lower Domerian (Causses, Mâconnais, Franche-Comté, Portugal) showed the settling down of the Protogrammoceras isseli group that set up and evoluated in a similar way in the different areas in spite of a certain originality.On the one hand, it gave the cladogenetic groupP. monestieri-nitescens by diminution of the ribing density, strengthening of the ribs and simplification of the suture.On the other hand, a slower evolution give, near the end of the Stokesi zone, P. normanianum in the Paris Basin and in Burgundy, and P. lusitanicum in Portugal. At the same time, a new invader, P. celebratum, arrived in the Causses (and in Portugal).     

Une faune inédite de coraux scléractiniaires dans le gisement chattien d'Escornebéou (Landes,SW France) ; stratigraphie,systématique et paléoécologie

The Escornebéou locality (Landes, SW Aquitaine Basin) is a reference site for the marine Chattian of atlantic tropical type. The abundant microorganisms allowed these outcrops to be allocated to the classic biozonations, after numerous historical controversies about their age. A fauna of Scleractinian corals has been discovered there for the first time, mainly from the ‘Le Bois’ site. About 25 taxa are listed and their systematics is analysed. They split up into 18 genera and subgenera, with stratigraphically a cachet intermediate between the Oligocene and Miocene faunas. There are as many solitary species as colonial ones (mainly hermatypics). The presence of numerous reefal genera confirms the tropical (to subtropical) paleoclimate, as well as the data from the other present organisms. Concerning the coarse zoogene calcareous deposits from ‘Le Bois’ (where the coral colonies are massive), the environment was shallow, fairly turbulent and under the effect of currents and waves. A subreefal facies locally developed (with mixed hermatypic and ahermatypic corals), belonging to the paleogeographic domain of shoal-type or barrier-type bioclastic limestones, as recognized elsewhere. At Escornebéou, the outcropping sequence is mainly marly to fine-grained sandy-marly (including such coarse calcareous intercalations), as at Lespeyrères, where few corals have also been found. These calm environments, of sheltered marine mud flat or seaweed type, were not very favourable to coral growth.     

Sur l’existence de deux espèces d’Eremotherium E. rusconii (Schaub, 1935) et E. laurillardi (Lund, 1842) dans le Pléistocène supérieur du Brésil intertropical

Two recent discoveries in two “lagoas” of southeastern Piauí (North East of Brazil) allow us to describe and compare two very small-sized hemimandibles of two Megatheriidae. We attribute the first one, from the Lagoa dos Porcos, to a very young specimen of Eremotherium rusconii (Schaub, 1935), the gigantic Eremotherium well known in South America. We determine the other one, from the Lagoa do Quari, as an adult specimen of the small Eremotherium laurillardi (Lund, 1842). We confirm hereby our idea, written in 2000, of the reality of the latter species, which was not defined, like many authors think, on a juvenile tooth of the large species. The mandible of E. laurillardi is described for the first time. The mandible of the very young specimen of E. rusconii is also a rare piece.     

Comportements alimentaires,aspects biologiques et sociaux au Néolithique : le cas du Crès (Hérault,France)

The aim of this article is to present an anthropological and stable isotope study (carbon and nitrogen) of 49 individuals from the Middle Neolithic population of Le Crès (Béziers, Hérault, France). The age, sex, stature and dental health were compared to the isotopic results to determine the possible relationship between diet and social behaviours. Results show no links between these parameters and the recorded isotopic variability. The study of the dental health shows a high level of attrition, related to the diet and a feminine tendency for caries.