Inner structural organization of the mandibular corpus in the late Early Pleistocene human specimens Tighenif 1 and Tighenif 2

The present study investigates the inner structural organization of the two mandible specimens Tighenif 1 and Tighenif 2 from the late early Pleistocene site of Tighenif, Algeria. Using (micro)tomographic scans, we built a new protocol to investigate the cortical bone topography at the post-canine level. We selected two cross-sectional slices placed between the P3/P4 and M1/M2 on the right and left sides and assessed the cortical bone thickness topography (CBT) on each slice. Our analyses demonstrate that the mandibles from Tighenif exhibit higher CBT and a different topographic distribution pattern at the molar level than in modern humans, resulting in a proportionally more robust inner structure, while a similar signal is observed between the fossil and extant specimens at the premolar level. Further studies need to be done in order to determine if this feature is related to functional constraints during mastication or paramasticatory activities; or if it is related to any independent evolutionary process.     

First record of Entelodontidae (Mammalia,Artiodactyla) from the late Eocene of Southeast Asia

We describe two entelodontid upper premolars that were recovered from the late Eocene of the Krabi coal mine in southern Thailand. The size and morphology of the material suggest that it can be referred to Entelodon aff. E. gobiensis, a species known from the late Eocene to the early Oligocene of northern Asia and southern China. The Thai material documents for the first time the southernmost occurrence of entelodontids in Asia during the Paleogene and also suggests that Eocene Southeast Asian mammal localities might potentially yield further entelodontid remains mostly associated with selenodont ungulates.     

Humanizing European Paleolithic art: A new visual evidence of human/bird interactions at L’Hort de la Boquera site (Margalef de Montsant,Tarragona, Spain)

This paper reports the discovery of a new example of portable art in North-eastern Iberia dating to the Late Upper Palaeolithic (12.250 ± 60 BP). The piece is analysed in relation to the European Palaeolithic art assemblage to determine its significance and how it contributes to our understandings of Palaeolithic artistic practices. Both the motifs depicted (birds and humans) and the patterns of composition (a narrative scene) are unusual in Palaeolithic assemblages. In addition, this new find contributes to filling a geographic gap in the artistic record as evidence of Palaeolithic art is rare in Catalonia. The anatomical features of one of the birds suggest that it is a crane, a species that has been depicted in a limited number of sites, as summarized in this paper. Moreover, there are only three known example of birds and humans interacting in a narrative scene in Palaeolithic art. Exhibiting innovations in media, subject matter and compositional norms, this new find has the potential to change the classic definition of European Upper Palaeolithic art and integrate the region in the artistic trends circulating along Mediterranean Iberia during the Upper Magdalenian.     

Campanian–early Eocene cephalopods from Kharga Oasis,Western Desert,Egypt

The Campanian–lower Eocene sedimentary succession in the Kharga Oasis yields rare cephalopods that have so far received little attention. Eight cephalopod species; six nautiloids and two ammonites, are identified in the study area. The nautiloids are referred to five genera in three families. All nautiloid species are recorded from the Paleocene and Eocene rocks, two of which are described as new, as follows: Cimomia kurkurensis nov. sp. and Deltoidonautilus hassani nov. sp. The two ammonite species are Libycoceras ismaelis (von Zittel, 1884) and Baculites ovatus Say, 1820, representing the families Sphenodiscidae and Baculitidae, respectively. Baculites anceps of Quaas (1902, non Lamarck, 1822) from the Maastrichtian of the Western Desert of Egypt is here assigned to Baculites ovatus. The palaeobiogeography of these species is studied in detail.     

Upper Cenomanian bivalves from the Guir Basin (southwestern Algeria): Order Veneroida

The Upper Cretaceous rocks are widely distributed and well exposed in south Algeria and consist in beds rich in macrofauna. For the first time, twenty veneroid species (Bivalvia) are systematically described from the upper Cenomanian deposits of the Guir Basin. While three species were reported since long before [Granocardium desvauxi (Coquand), G. productum (J. de C. Sowerby) and Glossus aquilinus (Coquand)]; Lucina fallax Forbes, Crassatella (Rochella) tenuicostata (Seguenza), Protocardia hillana (J. Sowerby), G. productum (J. de C. Sowerby) var. byzacenica (Pervinquière), Arctica cordata (Sharpe), A. humei (Cox), A. inornata (d’Orbigny), A. picteti (Coquand), Tenea delettrei (Coquand), Paraesa faba (J. de C. Sowerby), Meretrix desvauxi (Coquand) were previously unknown from the Cretaceous of Algerian Sahara. Because of reduced degree of preservation, Sphaera cf. corrugata J. Sowerby, Maghrebella cf. forgemoli (Coquand), Maghrebella sp., Granocardium cf. carolinum (d’Orbigny), Protocardia sp. and Meretrix sp. are tentatively determined. The studied material, found in the lower part of the “Calcaires de Sidi Mohamed Ben Bouziane” Formation, evidences palaeobiogeographic affinities occurring over a wide geographical area: from North Africa, southern Europe to Middle East and India. The present study provides new information to the knowledge of the upper Cenomanian palaeobiology of the studied region.     

Tapirus balkanicus nov. sp., nouveau tapir (Perissodactyla, Mammalia) du Turolien de Bulgarie

A new species of Tapiridae, Tapirus balkanicus, is etablished for new material of the Bulgarian Upper Miocene. The comparison with other Neogene tapirids leads us to consider the upper jaw as more characteristic than the lower one for taxonomic determination and study of phyletic relations. A new subgenus, Meyeriscus, is created for Tapirus pannonicus, the most evolved European tapirid.

Résumé

Une nouvelle espèce de tapir est décrite, Tapirus balkanicus du Miocène supérieur de Bulgarie. La comparaison avec les espèces européennes du Miocène moyen (Tapirus teilen) au Villafranchien (Tapirus arvernensis) amènent à privilégier la denture supérieure sur l'inférieure pour la détermination et les rapports phylétiques éventuels entre les espèces. Pour l'espèce la plus évoluée de tous les Tapiridés européens, Tapirus pannonicus est proposé un nom de sous-genre particulier, Meyeriscus nov.     

Lateglacial and Holocene vegetation history in the mountain range of central Pyrenees

We present the pollen analysis of a new sedimentary sequence taken at La Pouretère ( 1720 m), in the mountain vegetation zone of the Marcadau valley (central Pyrenees). The Lateglacial and Holocene chronology is supported by six 14C-dating results. The complementary analysis of some vegetal macroremains, stomata, pollen-clusters and the use of pollen influx allows us to elucidate the dynamic of mountain species such as Pinus and specially Abies but also to infer the unusual part played by Betula at the beginning of the Postglacial period.     

Contribution to the study of periodic chronic myelogenous leukemia

The period (in the order of 40 to 80 days) in periodic chronic myelogenous leukemia (PCML) oscillations is quite long compared with the duration of the cell cycle of the hematopoietic stem cells from which the oscillations are presumed to originate (in the order of one or two days). Our objective is to understand the origin of these long-period oscillations using a G0 model for stem cell dynamics. We determine the local stability conditions and show under what conditions the Hopf bifurcation may occur. We interpret the role of each parameter in the loss of stability, and then examine a simpler model to try to deduce possible changes at the stem-cell level that might be responsible for the characteristics PCML.