Isotopic biogeochemistry (C-13, O-18) of mammalian enamel from African Pleistocene hominid sites

The carbon. and oxygen isotope composition of carbonate in enamel hydroxylapatite can provide information on photosynthetic pathways of plants at the base of food webs, and on hydrological conditions. Retrieval of palaeoenvironmental information from isotopic composition of vertebrate fossils is complicated by potential diagenetic overprinting. In this study alteration has been assessed by examining the extent to which expected biological carbon and oxygen isotope patterns are disrupted in fossils of species whose diets cart be independently predicted by other criteria. The biological patterns used are 1) the differences in carbon, isotope composition between grazers and browsers, and 2) the differences in oxygen isotope composition between hippopotamus and terrestrial herbivores. Results obtained on, enamel samples from Tighenif (Algeria, approximate to 700,000 yr), Melka-Kunture (Ethiopia, 0.7-1.5 myr), and Anabo Koma (Djibouti, approximate to 1.6 myr) suggest that in vivo carbon and oxygen isotope compositions are preserved in most cases. Moreover, in all three regions, modern, patterns of C-3 versus C-4 grass dominance were present within the Pleistocene.