Scholars have debated why this early human relative had such strong jaws, indicating a diet of hard foods like nuts, yet their teeth seemed to be made for consuming soft foods. Damage to the tooth enamel also indicated they had come into contact with an abrasive substance. Previous research using stable isotope analyses suggests the diet of these homimins was largely composed of C4 plants like grasses and sedges. However, a debate has raged over whether such high-fibre foods could ever be of sufficiently high quality for a large-brained, medium-sized hominin.