Near Lake Turkana in northern Kenya, researchers have uncovered fossils of hand and foot bones belonging to an extinct relative of humans, dating back 1.52 million years. This significant discovery indicates that the species, known as Paranthropus boisei, possessed the ability to grasp and manipulate objects, including stone tools, and was fully bipedal.
This finding marks the first time that hand and foot bones can be confidently attributed to Paranthropus boisei. The excavated remains include a partial skeleton featuring most of the hand, three foot bones, several teeth, a partial forearm bone, and fragments of the skull. Previous fossils of this species had been largely fragmentary, making this new evidence particularly illuminating.
Paranthropus boisei is a part of the human evolutionary lineage, serving as a distant cousin to Homo sapiens, which evolved much later. This robustly built species had strong jaws and large teeth, adapted for chewing tough plant materials. Its skull featured a distinctive crest on top, which provided an anchor for powerful jaw muscles, while prominent cheekbones contributed to a characteristic dish-shaped facial structure.
According to Carrie Mongle, a paleoanthropologist from Stony Brook University and lead author of the study published in the journal Nature, “Sixty-five years after the original discovery of this species, this is the first time we can confidently link Paranthropus boisei to specific hand and foot bones.” The fossils were found in the Koobi Fora region, located on the eastern side of Lake Turkana.
Prior to this discovery, scientists had limited access to cranial and dental remains, leaving much of the species” anatomy unexplored. The structure of the hand bones suggests that Paranthropus boisei could form precision grips similar to those of modern humans, indicating potential capabilities for making and using stone tools. Louise Leakey, a paleoanthropologist and co-author of the study, noted, “We can tell that the hand of this species was built for forceful and sustained grips.”
Furthermore, the fossils provided insights into the species” locomotion, confirming that it walked upright on two legs. “From the few foot bones, we can deduce that it was fully bipedal, unlike a chimp, and would have had a lateral arch similar to modern human feet,” Leakey stated.
As members of the human evolutionary lineage, known as hominins, Paranthropus boisei was one of four hominin species coexisting in East Africa between one and two million years ago. Although stone and bone tools from this era have been discovered, it remained uncertain whether Paranthropus was capable of creating or utilizing such tools.
The genus Homo includes modern humans as well as extinct relatives, including Homo habilis, Homo rudolfensis, and Homo erectus, who lived concurrently with Paranthropus boisei. A study published last year revealed that both Paranthropus boisei and Homo erectus left overlapping footprints in the mud along the lakeshore at Koobi Fora, prompting questions about their interactions and competition for resources.
Traditionally, it was believed that while Homo species developed larger brains and advanced stone tool-making skills, Paranthropus boisei became a dietary specialist focused on grasses. Ultimately, this species went extinct, an evolutionary path that Leakey described as “an evolutionary dead end.”
