TY - CHAP T1 - Herbivore enamel carbon isotopic composition and the environmental context of Ardipithecus at Gona, Ethiopia AU - Levin, N. E. AU - Simpson, S. W. AU - Quade, J. AU - Cerling, T. E. AU - Frost, S. R. TI - The geology of early humans in the Horn of Africa SN - 978-0-8173-2446-1 PY - 2008 PB - Geological Society of America Special Paper VL - 446 SP - 215 EP - 234 ER -