The diet of Australopithecus sediba

Phytolith, stable carbon isotope, and dental microwear texture data for two individuals of Au. sediba , 2-million-year-old hominins from South Africa, show that they consumed a mostly C 3 diet that probably included harder foods, and both dicotyledons (for example, tree leaves, fruits, and wood or bark) and monocotyledons (for example, grasses and sedges); this diet contrasts with previously described diets of other early hominin species. Australopithecus enjoyed fruits of the forest Discovered in 2008, Australopithecus sediba is an approximately two-million-year-old hominin fossil from South Africa, related to other Australopithecus and early Homo species. Using a combination of stable-isotope analysis, dental-microwear patterns and analysis of plant microfossils extracted from dental calculus from two fossilized individuals, it is shown here that A. sediba consumed a diet consisting mainly of tree leaves, fruits and bark, suggesting that they resided in a woodland environment. This contrasts with previously described diets of other early hominin species that suggested an open-savanna habitat. Specimens of Australopithecus sediba from the site of Malapa, South Africa (dating from approximately 2 million years (Myr) ago) 1 present a mix of primitive and derived traits that align the taxon with other Australopithecus species and with early Homo 2 . Although much of the available cranial and postcranial material of Au. sediba has been described 3 , 4 , 5 , 6 , its feeding ecology has not been investigated. Here we present results from the first extraction of plant phytoliths from dental calculus of an early hominin. We also consider stable carbon isotope and dental microwear texture data for Au. sediba in light of new palaeoenvironmental evidence. The two individuals examined consumed an almost exclusive C 3 diet that probably included harder foods, and both dicotyledons (for example, tree leaves, fruits, wood and bark) and monocotyledons (for example, grasses and sedges). Like Ardipithecus ramidus (approximately 4.4 Myr ago) and modern savanna chimpanzees, Au. sediba consumed C 3 foods in preference to widely available C 4 resources. The inferred consumption of C 3 monocotyledons, and wood or bark, increases the known variety of early hominin foods. The overall dietary pattern of these two individuals contrasts with available data for other hominins in the region and elsewhere.