A newly discovered fossil of Paranthropus robustus, an early human relative, reveals that it walked upright like modern humans.
This species lived in South Africa around 2 million years ago, alongside Homo ergaster, a direct ancestor of today’s people.
Fossils of Paranthropus robustus have been found in large numbers at Swartkrans Cave, located between Johannesburg and Pretoria.
Over the years, scientists have studied its diet and social behaviors based on many skulls and teeth excavated from the site since 1948.
The species had strong jaws and thick teeth, suggesting that during tough times, it could survive on hard-to-chew, low-quality food.
Researchers also found differences in skull and tooth sizes, indicating that males were much larger than females.
This suggests Paranthropus robustus followed a mating system where dominant males had multiple mates.
Until now, scientists had few bones from the rest of the Paranthropus robustus skeleton, limiting their knowledge about its posture and movement. However, a major discovery at Swartkrans has changed that.
A team of international researchers from Wits University in South Africa found a set of bones—including a hipbone, thigh bone, and shin bone—that belonged to a single young adult Paranthropus robustus.
The discovery proves that this species walked on two legs regularly, just like humans. However, researchers were surprised to find that this individual was extremely small.
According to Professor Travis Pickering from the University of Wisconsin–Madison, who led the study, the fossil suggests this individual—likely a female—was only about 1 meter (3 feet) tall and weighed 27 kg (60 pounds).
This makes it even smaller than well-known early human ancestors such as “Lucy” (Australopithecus afarensis) and the “Hobbit” (Homo floresiensis).
Its small size likely made it an easy target for predators, such as sabertooth cats and giant hyenas. The team found bite marks and chewing damage on the bones, similar to marks left by leopards on their prey. This suggests the individual was killed and eaten by a predator.
Despite this, Paranthropus robustus was a successful species, surviving in South Africa for over a million years. Fossils of the species are often found near stone and bone tools, which were used for cutting meat and digging for food.
Scientists are still trying to determine whether Paranthropus robustus, Homo ergaster, or both were responsible for making these tools. However, the research team believes Paranthropus robustus had the intelligence and physical ability to use them.
Further studies, including CT scans of the bones, will help researchers learn more about how Paranthropus robustus grew, developed, and moved. This exciting discovery adds to our understanding of early human relatives and their way of life millions of years ago.
Source: KSR.
