The holotype of P. robustus was discovered at the site of Kromdraai, South Africa . The holotype is a partial skull with the Transvaal Museum reference number of TM 1517. It was discovered by a young schoolboy named Gert Terreblanche and the skull was described by Robert Broom in 1938 as a new genus and species . Excavations immediately following this discovery yielded relatively few hominins. Further discoveries of P. robustus were made during later excavations at Kromdraai B as well as at the sites of Swartkrans, Drimolen, Gondolin and Coopers.
It is difficult to estimate actual body size based on specimens recovered to date, but it is suggested that P. robustus has a predicted body weight approximating that of chimpanzees. The face of P. robustus is somewhat prognathic but flattened, thus the species is often referred to as the "flat-faced" ape man. P. robustus has relatively large dentition but not as large as the East African species P. boisei. The species name robustus was given for the large jaws and a pronounced sagital crest in males. Like other early hominin species, its canines are small relative to its posterior teeth. Based on recent discoveries - particularly at the site of Drimolen - it has been established that the species was relatively highly sexually dimorphic.
The dating of South African breccia caves is difficult, but it is hypothesized that the oldest P. robustus fossils date to around 1.9 million years old and the youngest finds are just over 1 million years old.
- Kromdraai, South Africa 1938
- Swartkrans, South Africa 1948
- Drimolen, South Africa 1992
- Gondolin, South Africa 1997
- Coopers, South Africa 1999
All fossils of P. robustus are held either at the Transvaal Museum, Pretoria or the University of the Witwatersrand, Johannesburg. The fossils held at the Transvaal Museum are from Swartkrans and Kromdraai and represent the early collections of Broom and later C.K. Brain. The University of the Witwatersrand holds specimens from Coopers and Drimolen.
Species subsumed under P. robustus
- Australopithecus robustus
- Paranthropus crassidens
- Paranthropus means "to the side of humans".
- Recent research has suggested Paranthropus made bone tools which it used for digging for termites, roots and tubers.
- Two specimens of Paranthropus - a male and a female of the same age (approximately in their late teens) - were found cheek by jowl at the site of Drimolen and named Orpheus and Eurydice by their discoverers.