Browsing and grazing in elephants: the isotope record of modern and fossil proboscideans.

The diet of extant elephants (Loxodonta in Africa, Elephas in Asia) is dominated by C3 browse although some elephants have a significant C4 grass component in their diet. This is particularly noteworthy because high-crowned elephantid cheek teeth represent adaptation to an abrasive grazing diet and because isotopic analysis demonstrates that C4 vegetation was the dominant diet for Elephas in Asia from 5 to 1 Ma and for both Loxodonta and Elephas in Africa between 5-1 Ma. Other proboscideans in Africa and southern Asia, except deinotheres, also had a C4-dominated diet from about 7 Ma (when the C4 biomass radiated in tropical and subtropical regions) until their subsequent extinction.