The recent discovery of a fossil belonging to a small human ancestor, Paranthropus robustus, in South Africa’s Cradle of Humankind has shed light on our ancient relatives. This young adult female stood at just 3 feet, 4.5 inches tall (1.03 meters), making her smaller than the famous Lucy and even the tiny "hobbits" from Indonesia.
The valuable fossils were found in the Swartkrans cave system and date back between 1.7 and 2.3 million years ago. It’s rare to find complete leg and hip bones from this species, highlighting the significance of this find. The individual, nicknamed SWT1/HR-2, likely had a short and stocky build, according to Travis Pickering, a paleoanthropologist at the University of Wisconsin–Madison. He compared her physique to that of modern pygmy populations, who typically have an average male height of under 4 feet, 11 inches (150 centimeters).
These early hominins were more than just walkers. Pickering noted that while her hip bones were robust, her leg bones showed some differences, suggesting P. robustus could move on two legs but might have also been capable of climbing. This adaptability could have been beneficial for avoiding predators or gathering food from trees.
Tragically, evidence suggests that SWT1/HR-2 may have met a violent end. Her bones showed marks consistent with animal teeth, likely from a leopard, indicating she may have been killed and partially eaten. Notably, her estimated weight of around 60.4 pounds (27.4 kg) fits within the prey size preferred by leopards, reinforcing this theory.
One intriguing question researchers are exploring is why P. robustus was so small. Unlike the "hobbits," which are thought to have experienced insular dwarfism due to living on a small island, there’s no evidence to suggest this here. Instead, scientists believe her size could be the result of natural variation within the species, population differences, or environmental influences like nutrition. Jason Heaton, a paleoanthropologist at the University of Alabama at Birmingham, emphasized that these factors might have shaped her development.
Further excavations could yield more fossils, helping to determine if SWT1/HR-2 represents a typical size for her species or if she was an exception. As our understanding of these early hominins expands, we gain valuable insights into the diversity of our ancestors and how they adapted to their environments.
For deeper insights, you can explore studies from the Smithsonian’s Human Origins Program, which provide a comprehensive overview of this fascinating species.
