Evolutionary ecology of Miocene hominoid primates in Southeast Asia.

The evolutionary history and palaeoecology of orangutans remains poorly understood until today. The restricted geographic distribution of extant Pongo indicates specific ecological needs. However, it is not clear whether these needs were shared by the great diversity of fossil pongines known from the Miocene to the Pleistocene. Here we show how niche modelling of stable carbon and oxygen isotope data of the carbonate fraction of dental enamel can be used to reconstruct the paleoecology of fossil and modern pongines and associated mammal communities. We focus on Khoratpithecus ayeyarwadyensis, a Late Miocene pongine from Myanmar and the sister clade to extant orangutans, and compare it to its associated mammal fauna and other fossil and extant pongines. The results are consistent with a vertical position high up in the canopy of a forested habitat with purely C3 vegetation for K. ayeyarwadyensis as well as the contemporaneous Sivapithecus. Although their positions in the modelled isotopic niche space look similar to the ecological niche occupied by modern Pongo, a comparison of the modelled niches within the pongine clade revealed possible differences in the use of microhabitats by the Miocene apes.

Contribution of collagen stable isotope biogeochemistry to the paleobiology of extinct endemic vertebrates from Tenerife (Canary Islands, Spain).

The paleodiet and paleoenvironmental context of two extinct species from Tenerife island, one giant rat Canariomys bravoi and one giant lizard Gallotia goliath, have been investigated using carbon and nitrogen isotopic compositions of fossil bone collagen. Preliminary to this study, a calibration of the isotopic variations of bone collagen from modern Rat Rattus rattus, Rabbit Oryctolagus cuniculus and Lizard Gallotia galotti relative to environmental conditions on Tenerife Islands has been attempted. No clear relationship could be found between collagen delta13C and delta15N values and aridity; the only relevant factors seem to be seashore proximity for rat, and the relative amount of C3 and CAM plants. It seems that anthropic activities have interfered with the expected relationships between collagen isotopic compositions and environmental conditions. Most fossil specimens yielded well preserved collagen. The isotopic composition of giant rat and giant lizard collagen suggest a purely C3 environment, possibly more humid than today on Tenerife. Large ranges of nitrogen isotopic compositions, especially within giant rats, may be due to local environmental conditions. Further work is needed in order to provide more valuable paleobiological information in order to better understand the role of environmental factors in the evolution and extinction of insular endemic species on Tenerife.

[Dietary behavior of the Middle Ages in Grenoble: application of isotopic biogeochemistry of the Saint-Laurent cemetery (XIIIth-XVth centuries, Isère, France)]. / Comportements alimentaires au Moyen Age à Grenoble: application de la biogéochimie isotopique à la nécropole Saint-Laurent (XIIIe-XVe siècles, Isère, France).

Isotopic analysis of 13C and 15N of 47 bones from Saint-Laurent de Grenoble cemetery (Grenoble, Isère), from the end of medieval period (XIIIth-XVth centuries AD) allowed to define the food status of animals with regard to the humans and to discuss the variability amongst adults. Adults who died young and those with small stature may have had diets poor in animal protein. The consumption of animal proteins was more important in the XVth than in the XIVth century and could illustrate a typical urban food economy providing its population with a more diversified diet than in rural areas.

Evidence from DNA that the mysterious 'linh duong' (Pseudonovibos spiralis) is not a new bovid.

In 1993, several horns of an unknown mammal were collected in the south of Vietnam. Due to the unusual characteristics of its horns, the 'linh duong', as named by Vietnamese hunters, was quickly described as belonging to a new monospecific genus of bovid, i.e. Pseudonovibos spiralis Peter & Feiler, 1994. The taxonomic status of Pseudonovibos was a highly controversial subject, and it has been suggested that this enigmatic species may be related to three different groups of Bovidae: Antilopini (gazelles), Bovini (cattle, bisons, buffaloes), and Caprini sensu lato (goats, sheep and allies). To assess the phylogenetic relationships of the linh duong within the family Bovidae, two different DNA markers, the nuclear lactoferrin and the mitochondrial cytochrome b genes, were sequenced from bone samples of four trophies collected during 1925 in Indochina. Results show that the mysterious horns of linh duong belong to domestic cattle (Bos taurus). Thus, the linh duong is not a new mammal and the scientific name Pseudonovibos spiralis should be abandoned.

[Lipids from fossil plants and their relation to modern plants. Example s of Cenomanian flora from Anjou and Bohemia]. / Les lipides des plantes fossiles dans leurs rapports avec les plantes actuelles. Exemples des flores cénomaniennes d'Anjou et de Bohême.

Comparative analyses of lipids from fossil plants and from their extant counterparts were undertaken in order to test the taxonomic significance of lipids in palaeobotany. The comparison between lipids from a fossil Ginkgoaceae, Eretmophyllum andegavense, and its extant counterpart, Ginkgo biloba, revealed the presence of original molecules, dimethoxyalkylcoumarins, in lipids from both plants. Such compounds confirm, on chemical grounds the relationship between these extant and fossil Ginkgoaceaes. Moreover, differences in n-alkane distribution between E. andegavense and E. obtusum which are very similar morphologically, confirm that these fossil plants do not belong to the same species. Furthermore, comparative analyses of a fossil Cheirolepidiaceae, Frenelopsis alata, and its extant counterpart, the Cupressaceae Tetraclinis articulata, revealed some similarities between these two species although they do not belong to the same family. Otherwise, comparative analyses of fungi-infected and uninfected samples of F. alata demonstrated that these micro-organisms can significantly affect the chemical composition of fossil plant lipids. In conclusion, even if chemical analyses alone are not sufficient to determine the genus or species of a given fossil plant, they can precise the taxonomy of some specimens that have been previously studied by palaeobotanists.

[A comparison of trace element and isotope analysis in archeological bones (exemplified by a medieval bone series from Weingarten, Germany)]. / Spurenelement- und Isotopenanalyse in archäologischem Knochen im Vergleich (am Beispiel der mittelalterlichen Skelettserie von Weingarten, Deutschland).

The well established methods of isotope- and trace element analysis have been used as a reliable approach in archaeometry in order to reconstruct ecological and social parameters. Both methods offer access to palaeoecological information, however, frequently only one of the methods has been applied on the onegiven material. Up to now, isotope data are especially associated to the determination of food webs and palaeocliamtes, i.e. the position of the examined subjects within an ecological context is englightened. On the other hand, trace element analyses reveal knowledge about group specific nutrition and pollution with toxic substances. For the medieval human bone series of Weingarten (Germany), both methods have been applied independently. The results suggest special emphasis of diagenesis for the interpretation of trace element data: diagenesis and its impact on the stability of biological signals as well as consequences for data interpretation, which is dependent on the analysed phase of the material (mineral or gelatine) and its preservation.

Isotopic biogeochemistry as a marker of Neandertal diet.

Natural abundances in 13C and 15N of bone collagen are linked to those of the diet. This isotopic signal can thus be linked to the dietary parameters of a given individual, such as the plants at the beginning of his food web and his position in the trophic web. In order to use this approach to study the diet of ancient humans, it is crucial to be sure that the original isotopic abundances of fossil collagen are preserved. This is done by controlling the biochemical purity of the organic matter extracted from fossil bones, and by checking that the isotopic differences observed in modern environments between herbivorous and carnivorous species are indeed measured in the fossil samples. Upper Pleistocene sites with a good isotopic preservation of collagen have been recognized in temperate and arctic environments. The isotopic signatures measured in such sites highlight particularities of the "mammoth steppe" fauna, and improve our knowledge of the diet of Neandertals.

Molecular preservation and isotopy of Mesolithic human finds from the Ofnet cave (Bavaria, Germany).

Favourable burial conditions and self-limiting decomposition processes led to an extraordinarily well molecular preservation of the Mesolithic human skull finds from the Ofnet cave (district Nördlingen, Bavaria). Beyond the extraction of bone collagen, a selection of serum proteins from bone was identified immunologically. Stable carbon and nitrogen isotope ratios from collagen gave clues to dietary behaviour including nursing practices. Diverging results after the application of biochemical protocols (for protein cleaning) and biophysical methods (for stable isotope analysis) are of particular interest: while the first approach failed to quantitatively eliminate anorganic contaminations, the second left some organic, exogenous residues in the samples. Thus, methods for protein extraction must vary according to problem solution and ultimate aim of the study. Taking this into account, application of invasive methods is also encouraged to rare and valuable skeletal finds.

[Isotopic signatures in ancient bone collagen]. / Signatures isotopiques dans le collagène des os anciens.

Collagen can be preserved during tens of thousands of years in bones and teeth under favorable conditions. Natural isotopic abundances in carbon (13C/12C) and in nitrogen (15N/14N) of ancient bone and tooth collagen correspond to those recorded during the biogenic synthesis and have not been significantly altered during fossilization. These isotopic abundances are linked to those of the proteic fraction of animal and human diets, and to physiological conditions. Three kinds of applications are made possible through these natural isotopic signatures: determination of subsistence strategies in ancient human populations, determination of the diet of extinct species and the analysis of past environmental changes.