Reconstruction of the diet of Paranthropus has been hampered by seemingly contradictory signals from functional morphologyMorphology, stable carbon isotopesIsotopes (Stable)carbon, and dentalMicrowear microwearDental microwear. Abrasives including exogenous gritExogenous grit and silica phytolithsPhytolith in foods have long been implicated in the creation of microscopic features on teethTeeth and in dental wearDental wear. Yet the etiology of microwearMicrowear features, particularly of pits, and the ability of some silicates to cause wear, are still controversial. We question the widely held view that consumption of “hard objects,” e.g. nuts and seeds, can be discerned in microwear and review some pertinent recent studies that address these questions. Some describe microwear patterns and wear created by diets with differing amounts of silica phytolithsPhytolith and exogenous gritExogenous grit; others report new findings on the relative hardnessHardness of dietary silicates. We review recent evidence and arguments for a “dietary abrasiveness”Dietdietary abrasiveness hypothesis to explain dentalMicrowear microwearDental microwear, including the patterns produced by the diets of Paranthropus.