Carbon isotope ratios of mammalian teeth from the Kanapoi site in northern Kenya are interpreted in the context of C₃ and C₄ derived resources to investigate the paleoecology of Australopithecus anamensis. δ¹³C values of large mammals, when compared at the taxon level, show an ecosystem that is strongly biased towards mixed feeders and browsers. However, sufficient C₄ resources were present such that some C₄ dominated grazers were also present in the large mammal fauna. Analyses of micromammals shows that their diets were C₃ dominated or C₃–C₄ mixed. Carbon isotope studies of primates shows that the major primate tribes—Colobini, Papioini, Hominini—all made some use of C₄ resources in their respective diets; the Hominini had a higher fraction of C₃ diet resources than the other primate tribes represented in the fossil record.

在C ₃和C ₄衍生资源的背景下，对肯尼亚北部Kanapoi遗址哺乳动物牙齿的碳同位素比进行了解释，以研究南方古猿。δ ¹³大型哺乳动物的C值，当在分类单元水平相比，表明强烈朝向混合馈线和浏览器偏置的生态系统。但是，存在足够的C ₄资源，因此大型哺乳动物动物群中也存在一些以C ₄为主的放牧者。对微哺乳动物的分析表明，他们的饮食以C ₃为主或C ₃ –C ₄混合。灵长类动物的碳同位素研究表明，主要的灵长类动物部落（Colobini，Papioini，Hominini）在各自的饮食中都使用了C ₄资源。Hominini的C ₃饮食资源比例高于化石记录中所代表的其他灵长类动物部落。