New find in South Africa: ancient human ancestor walked on two legs and was tiny

This species coexisted with Homo ergaster, the direct ancestor of modern humans. Until now, scientists have had many skulls and teeth of Paranthropus robustus, but few fragments to assess the height, physique and mode of locomotion of these hominins.

An unusual find from Swartkrans Cave

Researchers from a number of scientific organisations, including the Evolutionary Studies Institute at the University of the Witwatersrand (South Africa), have presented the results of the analysis of a new series of bones from the pelvis, femur and tibia. It turned out that they all belong to the only young adult representative of the species Paranthropus robustus. These bones demonstrate for the first time that:

1. Paranthropus robustus walked upright, like humans;
2. This species was very small in size - the most likely individual found (probably a female) was only about 1 metre tall and weighed 27kg.

According to Professor Travis Pickering of the University of Wisconsin in Madison, such tiny proportions make this specimen smaller than the famous "Lucy" (Australopithecus afarensis) and even "hobbit" (Homo floresiensis).

Analyses of the surface of some of the bones of Paranthropus robustus have shown tooth impressions similar to those of leopard fangs. This suggests that small and fragile individuals of Paranthropus robustus were victims of large predators that lived in the region 2 million years ago.

At the same time, scientists emphasise that the very fact of death of one representative from the paws of a leopard does not cast doubt on the adaptability of the entire species to life in the African savannahs. Paranthropus robustus, according to archaeological data, lived in this area for about a million years and left numerous stone and bone tools, which may have been able to make and use for food extraction.

Significance of the find

1. Increased understanding of walking and posture: A new series of bone artefacts provides clear evidence that Paranthropus robustus possessed anatomical adaptations for upright walking.
2. Modest size: The fact that individuals of this species may have been even smaller than Lucy speaks to the diversity of early hominin forms.
3. Future research: Scientists plan to use CT scans to further understand the bone structure and growth of Paranthropus robustus, as well as to study their modes of locomotion and "lifestyle" in more detail.

The study helps provide a better understanding of the evolutionary context of the hominin 'family': different lineages of early human ancestors coexisted, had different food adaptations, and differed in size and behavioural survival strategies. The new data may suggest exactly how Paranthropus robustus fits into the overall scheme of human evolution, along with Homo ergaster and other ancient species.

Research:
Travis Rayne Pickering et al, First articulating os coxae, femur, and tibia of a small adult Paranthropus robustus from Member 1 (Hanging Remnant) of the Swartkrans Formation, South Africa, Journal of Human Evolution (2025). DOI: 10.1016/j.jhevol.2024.103647