Paranthropus robustus

Overview

Locations of fossils

Diet

Defining Features

Image: P. robustus rendering Source: https://www.bradshawfoundation.com/origins/paranthropus_robustus.php

Overview

Paranthropus meaning beside human(3)

robustus meaning strongly built(3)

Lived during the Pleistocene Epoch, ca. 2.2-1.5 million years ago(3).

Locations of fossils

Most of these sites were or still are caves, made of dolomitic limestone, located in the "Cradle of Humankind"(3).

Kromdraai, South Africa

about a dozen individuals

Image: Kromdraai, South Africa Source: https://www.dw.com/de/wiege-der-menschheit-kromdraai/a-64219794

Swartkrans, South Africa

over one hundred individuals

Image: Swartkrans, South Africa Source: https://www.facebook.com/photo.php?fbid=101385723284886&id=101380283285430&set=a.101383519951773&locale=ps_AF

Drimolen Cave System

tens of individuals including DNH7

Image: Drimolen Cave System Source: https://communities.springernature.com/posts/drimolen-cranium-dnh-155-documents-microevolution-in-an-early-hominin-species

Cooper's Cave

partial cranium

Image: Cooper's Cave Source: https://commons.wikimedia.org/wiki/File:Cooper%27s_Cave_South_Africa.jpg

Gondolin Cave

lower molar

Image: Gondolin Cave Source: https://www.newscientist.com/article/2263973-treasure-trove-of-ancient-human-remains-hints-at-undiscovered-species/

Image: DNH 7 skull, showing the powerful jaw of P. robustus. Source: https://www.mchenry.edu/origins/species/paranthropus-robustus.html

Diet

P. robustus were initially believed to be herbivores, however carbon isotope testing and tooth enamel wear revealed evidence that P. robustus were more likely omnivores(3).

It is widely believed they ate savannah based foods such as grasses, seeds, roots, pith and tubers as well as the small animals or insects that also ate these plants. It is also possible P. robustus ate bulbs and anthills(3).

The jaw of this species are designed for eating hard foods, meaning they most likely had a plant based diet with small amounts of meat(3).

Defining Features

Overall, P. robustus is much more robust compared to the genus Australopith. P. robustus possess wide, flaring zygomatics, megadont molars, a flatter face, relatively large browridge, a mildly present sagittal crest and show significant evidence of bipedalism(1-2, 4-6).

Image: SK 48 skull, showing the browridge, flat face and sagittal crest. Source: https://humanorigins.si.edu/evidence/human-fossils/fossils/sk-48

Sexual Dimorphism

It was initially believed that P. robustus had minimal sexual dimorphism because of the limited number of specimens. However the discovery of DNH 7 changed this way of thinking. The significantly smaller fossil is thought to be a female, if this is correct it proves that P. robustus displays a large degree of sexual size dimorphism(3).

Male P. robustus - 1.2 meters tall, 54 kg in weight(7)

Female P. robustus - 1 meter tall, 40 kg in weight(7)

TM 1517

Found by school boy Gert Terblanche in Kromdraai, South Africa in 1938, TM 1517 is the type specimen for the species Paranthropus robustus. Robert Broom is credited officially to having found P. robustus, but he writes credit to the school boy in his article. In total, the 2 million year old fossil TM 1517 consists of a partial skull and lower jaw, as well as postcranial fragments including a distal right humerus, proximal right ulna, and a distal left phalanx of the hallux(1). Upon review it has been agreed that TM 1517 is an immature individual. Some of the morphologies of P. robustus include a flatter face than most African apes, smaller canine teeth, and a more centrally located occipital condyle, indicating bipedalism(2,4).

Image: articulated cast of TM 1517 Source: https://www.donsmaps.com/robustus.html

Image: partial cranial and post cranial remains of TM 1517 Source: https://www.sciencephoto.com/media/170827/view/type-specimen-of-the-hominid-paranthropus-tm-1517

Image: fossil of TM 1517 Source: https://www.donsmaps.com/robustus.html

DNH 7

Commonly known as Eurydice, DNH 7 is the most complete skull of any P. robustus found to date. Discovered by Andre W Keyser in 1994 at the site Drimolen, South Africa, Eurydice is widely believed to be female due to the much smaller, more gracile build. Morphologies include a sagittal crest, wide zygomatics, flat face, large post canine teeth, exterior anterior pillars and a present browridge. These morphologies follow those of TM 1517, the type specimen for P. robustus, but each feature is much more gracile, further exemplifying the sexual dimorphism of this species(5-6).

Image: frontal view of skull of DNH 7 Source: https://www.sciencedirect.com/science/article/pii/S0047248420301743

Image: articulated view of skull of DNH7 Source: https://humanorigins.si.edu/evidence/human-fossils/fossils/dnh-7

Image: lateral view of skull of DNH 7 Source: https://www.sciencedirect.com/science/article/pii/S0047248420301743

Image: Hominin evolutionary tree. Source: https://www.nhm.ac.uk/discover/the-origin-of-our-species.html

Evolutionary Tree

Dating to the Pleistocene epoch, more specifically 2.2 to 1.5 million years ago, where P. robustus fits into the evolutionary tree is debated(7). Is this a human ancestor? Is this a died out, distant cousin? Without DNA it is hard to know for certain, however it is widely believed that P. robustus is somehow related to humans. Mounting evidence, as well as dating, proves that P. robustus is older than anatomically modern humans, but did exist at a time with other hominin species such as Homo erectus and Australopithecus sediba(7).

Sources

Broom, R. The Pleistocene Anthropoid Apes of South Africa. Nature 142, 377–379 (1938). https://doi.org/10.1038/142377a0
Cazenave M;Dean C;Zanolli C;Oettlé AC;Hoffman J;Tawane M;Thackeray F;Macchiarelli R; “Reassessment of the TM 1517 Odonto-Postcranial Assemblage from Kromdraai B, South Africa, and the Maturational Pattern of Paranthropus Robustus.” American Journal of Physical Anthropology, U.S. National Library of Medicine, Aug. 2020, pubmed.ncbi.nlm.nih.gov/32449177/.
Kaszycka, K.A. (2017). Paranthropus robustus. In: Shackelford, T., Weekes-Shackelford, V. (eds) Encyclopedia of Evolutionary Psychological Science. Springer, Cham. https://doi.org/10.1007/978-3-319-16999-6_3431-1
Kgasi, Lazarus. “The First Ape-Man of Kromdraai Cave (TM 1517).” Ditsong Museums of South Africa, 29 July 2021, ditsong.org.za/en/the-first-ape-man-of-kromdraai-cave-tm-1517/.
Rak, Yoel, et al. "The DNH 7 Skull of Australopithecus Robustus from Drimolen (Main Quarry), South Africa." Journal of Human Evolution, vol. 151, 2021, https://doi.org/10.1016/j.jhevol.2020.102913.
“DNH 7 | The Smithsonian Institution’s Human Origins Program.” Smithsonian Institute, humanorigins.si.edu/evidence/human-fossils/fossils/dnh-7. Accessed 1 Apr. 2025.
“Paranthropus Robustus | The Smithsonian Institution’s Human Origins Program.” Smithsonian Institute, humanorigins.si.edu/evidence/human-fossils/species/paranthropus-robustus. Accessed 1 Apr. 2025.