abstract: Paleosols (fossil soils) were sampled across a 9km west to east curvilinear transect of the Aramis Member of the Sagantole Formation in the Middle Awash Valley. Paleosol carbon isotope ratios are interpreted as reflecting floral habitats with 30% to 70% C 4 grass biomass, representing woodlands to wooded grasslands (WoldeGabriel et al. Science 326: 65e1-5, 2009). Pedogenic carbonate carbon and oxygen isotope ratios increase from west to east, reflecting grassier, drier habitats on the east, wher
journal: PaleoAnthropology