Getting to the roots of our ancient cousins’ diet

The splay of tooth roots reveals how South African hominins  Australopithecus africanus and Paranthropus robustus  chewed their food, researchers have found. Ever since the discovery of the fossil remains of Australopithecus africanus from Taung nearly a century ago, and subsequent discoveries of Paranthropus robustus , there have been disagreements about the diets of these two South African hominin species. By analysing the splay and orientation of fossil hominin tooth roots, an international team of researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig, the University of Chile and the University of Oxford now suggests that Paranthropus robustus had a unique way of chewing food not seen in other hominins, which seems to explain the unique suite of characters observed in this species. Food needs to be broken down in the mouth before it can be swallowed and digested further. How this is done depends on many factors, such as the mechanical properties of the foods and the morphology of the masticatory apparatus. Palaeo-anthropologists spend a great deal of their time reconstructing the diets of our ancestors, as diet holds the key to understanding our evolutionary history. For example, a high-quality diet (and meat-eating) likely facilitated the evolution of our large brains, while the lack of a nutrient-rich diet probably underlies the extinction of some other species (for example, P. boisei ).