C and N stable isotope measurements on Eurasian fossil mammals, 40 000 to 10 000 years BP: Herbivore physiologies and palaeoenvironmental reconstruction

Seventy-seven specimens of fossil (Upper Pleistocene-Early Holocene) woolly mammoth, reindeer, deer and bison from 17 different locations in Eurasia h ave been measured for the nitrogen and carbon stable isotope composition of their collagen and for the carbon stable isotope composition of bioapatite . The aim was: (1) to check the existence of differences in N and C isotope ratios between and within different herbivore species (mainly between mamm oth and reindeer); (2) to discuss these data in terms of animal physiology, temporal and spatial distribution of animals and effects of climatic chang es; and (3) to obtain further information about the environmental changes t hat occurred in that area during the period considered. A geographical vari ation from south-west to north-east in the delta N-15 and/or delta C-13 val ues of collagen and bioapatite for all the herbivore species is apparent, t he most negative delta C-13 values and the most positive delta N-15 values bring located in the north-eastern area. This was probably due to a differe nt temperature and water stress on animals and plants and to a different pl ant availability. The differences in C-13/C-12 and N-15/N-14 isotope ratios among species are mainly related to different food intake and different me tabolic pathways. It seems also that the diet of mammoths from north-easter n Siberia was higher in protein content compared with that of mammoths from the Russian Plain. From this study, it is clear that there was a rapid and important change in the amount of precipitation soon after the last glacia l maximum; the rainfall conditions around 40 000 and 30 000 years BP were p robably similar to those existing around 10 000 years BP, though lower than those existing after the glacial maximum. (C) 2000 Elsevier Science B.V. A ll rights reserved.