Specimen SK 46 preserves the left half of the braincase and the nearly complete palate of Paranthropus robustus, a large-toothed species of early human from Swartkrans, South Africa. The cheek teeth are nearly perfectly preserved (seen in the lower photograph). Although the incisors and one canine tooth have been lost, their alveoli (the bony pits that hold the tooth roots) remain. Because these alveoli are still preserved, paleoanthropologists are able to reconstruct the size of the cheek teeth (molars and premolars) relative to the incisors and canines. This information can give clues about the dietary habits of this early human species. In the lower photograph, look at the large size of the cheek teeth relative to the front teeth. Compare this, for example, to the earlier species Australopithecus afarensis: AL 200-1. An increase in the relative size of the cheek teeth suggests that Paranthropus robustus had a diet dominated by coarse vegetable matter. The large teeth provided a large occlusal area (the area where the upper and lower teeth contact each other during chewing). Think about a cow, or a horse, both of which eat large amounts of grass and other coarse plant foods. These animals have large cheek teeth and large chewing surfaces. By this kind of analogy and by direct study of microscopic wear on the tooth surfaces, paleoanthropologists have determined that the large cheek teeth of robust australopiths were used for grinding tough, fibrous foods.

The preserved portion of the cranium demonstrates other features typical of P. robustus, including large zygomatic arches and a prominent sagittal crest, partially preserved and visible in the top photograph. These features are associated with large chewing muscles used in grinding tough foods.