Discovered by a schoolboy, fragmentary remains of hominid teeth led South African paleoanthropologist Robert Broom to the site of Kromdraai. While only one and a half kilometers from Sterkfontein (the site where Broom had discovered remains of Australopithecus africanus), the teeth, jaw, and face recovered from Kromdraai indicated to Broom that this early human was fundamentally different from that of Sterkfontein. Broom chose a new species name, Paranthropus robustus, and TM 1517 represents the type specimen. Since then, paleoanthropologists have called into question the validity of the genus Paranthropus, and many researchers have preferred to use the genus Australopithecus for all early humans before Homo. In recent years an increasing number of researchers have advocated using the term Paranthropus, the name that implies that all robust lineages belong in a single evolutionary group. The paleoanthropological community is split as to which term is correct. Here we use Paranthropus.

TM 1517a (top three photographs) is a partial cranium that preserves much of the left side of the face of an adult Paranthropus robustus. The premolars and the first two molars remain as part of the specimen. The incisors and canines were lost, although the openings for the tooth roots remain and indicate that the front teeth were very small in comparison to the cheek teeth, a feature typical of robust australopiths.