The latest Miocene Rhinocerotidae from Sahabi (Libya)

The Rhinocerotidae material from the latest Miocene of Sahabi (Libya) is here revised in detail in order to clarify its systematic position and the paleobiogeographic implications. The family is represented by four specimens only at Sahabi, a phalanx, a mandible, a second upper molar (M2), and a second upper premolar (P2). Except for the phalanx, which can be only identified at the family level, the morphology and the dimensions of these specimens have revealed the presence of three taxa: Aceratheriini vel Teleoceratina, Brachypotherium lewisi and ‘Diceros’ sp. The presence of the large-sized B. lewisi has been suggested in several papers, but without a detailed comparison or critical revision. The Brachypotherium from Sahabi also resembles Brachypotherium heinzelini, suggesting a probable synonymy between this species and B. lewisi. A P2 from Sahabi differs from several species belonging to Ceratotherium, including Ceratotherium neumayri, and it resembles the genus Diceros. The rhinoceros association (Brachypotherium and a dicerotine) recognized at Sahabi has been recorded at Lothagam (Kenya), suggesting a biogeographic affinity with the eastern Africa assemblage.     

Avian fossil assemblages at the onset of the LGM in the eastern Alps: A palaecological contribution from the Rio Secco Cave (Italy)

The avian fossil assemblages from the late Pleistocene deposits of the Rio Secco Cave (north-eastern Italy) is presented herein. We studied the layers that date back to the end of MIS3 and the beginning of MIS2, which also contain evidence of Gravettian frequentation dated to 33.5–30 ka cal BP. The systematic analysis revealed the presence of 18 species and other supraspecific taxa that supported palaeoenvironmental reconstructions. Taxa indicate that, at the onset of LGM, site surroundings were characterised by conifer or mixed forests, open grasslands, slow-flowing water bodies and mountain meadows with rocky outcrops, as indicated by Lagopus muta. Today, this environment is found above the tree line (beyond 1500–2000 m) and cannot be detected near the site, located at 580 m asl. Noteworthy, is also the finding of the second Italian late Pleistocene fossil record of Picus canus.     

Évolution et transformation des industries lithiques taillées et polies durant le Chalcolithique et l’Âge du Bronze en Corse

Lithic industries in Corsica have been subject to important modifications during the 3rd and 2nd millennium cal. BC. Polished tools changed almost totally during that period, the majority of all lithic tools disappeared. The development of metallurgy is probably the main reason for these changes; they show the new place of lithic productions in the activities of the different communities within the island.     

A small stem-galliform bird (Aves: Paraortygidae) from the Eocene of Uzbekistan

Landfowl (order Galliformes) are among the most characteristic birds of the modern avian faunas, but their early evolutionary history is insufficiently known. The diversity of previously described Eocene galliforms implies a great role of Eocene diversification in the early evolution of this group. However, almost nothing is known about the Eocene diversity of galliforms in Asia, even though this large continent with a variety of habitats might have played a significant role in their early evolution. Here we describe a partial coracoid from the Lutetian–Bartonian of Uzbekistan, which is the oldest diagnosable galliform bird in Asia, and is further the first landbird known from this geographical area. The specimen displays a unique morphology with few autapomorphies and an unexpected combination of similarities with the African genus Scopelortyx and Eurasian Paraortyx, and hence is described as a new taxon, Xorazmortyx turkestanensis gen. et sp. nov., within the extinct family Paraortygidae, being the first Asian representative of this clade. Similarities with the African genus Scopelortyx indicate a connection of land bird faunas between northern Africa/Arabia and Asia in the middle Eocene. Better dispersal abilities of the early galliforms Paraortygidae are inferred from the osteology of their pectoral girdle and the humerus, which do not show adaptations to the powerful burst take off (escape flight), characteristic of most modern Phasianidae.     

Catalytically active hybrids formed in vitro between large and small subunits of different procaryotic ribulose bisphosphate carboxylases

Ribulose bisphosphate carboxylase from the procaryotic green alga, Prochloron (the symbiont of Lissoclinum patellum), has eight large and eight small subunits, and a low affinity for CO2, similar to that of cyanobacterial carboxylases. The small subunits were progressively removed from this carboxylase and from that from the cyanobacterium, Synechococcus ACMM 323, by twice-repeated, mild-acid precipitation. This procedure produced large-subunit octamers, greatly depleted in small subunits, as well as isolated small subunits. Catalytic activity of the large-subunit preparations reflected their residual small-subunit content. The two large-subunit preparations were reconstituted with both homologous and heterologous small subunits. The reassembled enzymes were catalytically competent in all cases. When fully saturated with small subunits, the hybrid enzymes were only about 20% less active than the homologously reconstituted enzymes. Heterologous reconstitution underscores the essential function of the small subunits in catalysis.     

Bioconstructions bajociennes a madréporaires et faciès associés dans l'Île Crémieu (Jura du Sud; France)

First of all this study brings necessary details aboutregional stratigraphy. It goes on to reconstitute the paleobiocenoses and the environmental conditions of bajocian coral limestone deposits: weak currents, fairly high depth, varied substrates, low relief. In the low areas scleractinians disappear and are replaced by sponges, Pseudomelania or pholadomyes communities. In order to explain the particularities of bajocian constructions, some hypothesis have been put forward, mentioning the slope of the platforms, the speed of the growth of organisms and the stability of the sea-level.