Discovery: These human ancestors walked upright over 2 million years ago

The tapestry of human evolution is adorned with fascinating episodes and, among them, the story of Paranthropus robustus from the Cradle of Humankind in South Africa stands out as a testament to survival, adaptation, and dominance.

This ancient hominin species, also referred to as Australopithecus robustus, inhabited the terrains of South Africa approximately 2 million years ago. It shared this region with Homo ergaster, which is believed to be a direct forerunner of modern humans.

The Swartkrans Cave, that is nestled halfway between Johannesburg and Pretoria, is a treasure trove of Paranthropus robustus fossils.

Archaeological pursuits at this site since 1948 have helped unearth a multitude of insightful details about the extinct species’ dietary patterns and social arrangements.

But a recent groundbreaking discovery is now reshaping what we know about the physical traits and way of life of these early hominins, offering a rare glimpse into how they moved, survived, and interacted in a prehistoric landscape.

Life and traits of Paranthropus robustus

Paranthropus robustus was equipped with extraordinarily heavy jaws and thickly coated teeth – an adaptation for enduring lean times by when individuals would have needed to consume low-grade, tough foods.

Fossilized skulls and teeth of this species have been excavated in several different locations in the Cradle of Humankind.

The skulls and teeth provide fascinating insights into the social structure of these hominins. Some are exceptionally large, suggesting that they were probably males, while others are smaller and likely to have been females.

This physical difference suggests that Paranthropus robustus probably engaged in polygyny – a system of mating where one dominant male mates with several females.

But until now, the scarcity of fossilized bones from the rest of the post-cranial skeleton has impeded our knowledge of their body type, posture, and locomotion – key characteristics associated with their diet and mate searching behavior.

A recent groundbreaking find in the Swartkrans Cave is, however, poised to reverse this paradigm.

Discoveries at Swartkrans cave

Recently, an international team of researchers based at the Evolutionary Studies Institute at the University of the Witwatersrand in South Africa made a fascinating discovery.

Their dig resulted in the exposure of the very first articulating hipbone, thigh bone, and shin bone of a Paranthropus robustus individual.

This groundbreaking discovery provides us with valuable information regarding the existence and features of this prehistoric hominin species.

The newly discovered fossil not only illustrates that Paranthropus robustus primarily moved around by walking upright (similar to the locomotion of modern humans), but also reveals their surprisingly petite size.

“It is estimated that this individual, probably a female, was only about a meter tall (3.3 feet) and 27 kg (60 pounds) when it died, making it even smaller than adults from other diminutive early human species, including those represented by the famous ‘Lucy‘ (Australopithecus afarensis; about 3.2 million years old) and ‘Hobbit’ (Homo floresiensis; about 90,000 years old) skeletons, from Ethiopia and Indonesia, respectively,” explained Professor Pickering from the University of Wisconsin–Madison, who spearheaded the research.

Predators, prey, and survival instincts

The compact size of the prehistoric Prananthropus robustus rendered them vulnerable to predators, such as sabertooth cats and giant hyenas, who roamed the areas surrounding Swartkrans Cave.

This hypothesis is supported by the team’s identification of tooth marks and chewing damage on fossilized P. robustus bones. These marks are identical to those made by leopards when they chew on their prey.

Yet, their small size didn’t necessarily hinder their survival.

“Although it seems that this particular Paranthropus robustus individual was the unfortunate victim of predation, that conclusion does not mean that the entire species was inept,” Pickering stresses.

Their existence in South Africa for over a million years attests to their endurance, and the presence of stone and bone tools near their fossils suggests a degree of intelligence.

What happens next?

In order to learn more about the growth and developmental patterns of Paranthropus robustus, as well as their locomotion behaviors, the team is currently doing research that includes CT-scan examinations of internal bone structures.

This study has the potential to advance our knowledge of human evolution and add fresh chapters to the intriguing story of Paranthropus robustus.

Daily lives of Paranthropus robustus

Outside of their skeletal system and survival habits, knowledge of the daily existence of Paranthropus robustus gives greater insight into what they were like.

Scientists surmise that the early hominins lived in small groups and most likely scavenged in groups in the woodland and open savannas that surrounded the Swartkrans Cave.

They ate largely tough plant matter, such as roots, tubers, and seeds, to which their heavy-duty jaws and heavily enamel-coated teeth were best suited.

Proof of stone and bone tools alongside their fossils evokes intriguing questions regarding their level of cognitive skills.

Although not as sophisticated a tool maker as the subsequent hominin species, P. robustus might have utilized basic tools to assist with food preparation and tuber excavation.

Such resourcefulness implies that Paranthropus robustus was more cunning than previously realized, and was potentially able to manipulate its surroundings in order to enhance survival prospects.

As scientists go on to examine fossilized bones and related artifacts, every finding is a step towards piecing together the complicated world of Paranthropus robustus, a species that flourished under difficult prehistoric conditions.

The full study was published in the journal Journal of Human Evolution.

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