Researchers have discovered the first confirmed fossil hands of Paranthropus boisei, an ancient hominin that lived around 1.5 million years ago. The find reveals that this species possessed human-like hand proportions for tool-making alongside the robust strength of a gorilla. The partial skeleton, including hands, a skull, and foot bones, was unearthed near Lake Turkana in Kenya.
Paranthropus boisei, first identified by archaeologist Mary Leakey in 1959 at Olduvai Gorge in Tanzania, was initially linked to Oldowan stone tools found nearby. However, without hand fossils, it remained uncertain whether this species made them. Now, palaeontologist Louise Leakey of Stony Brook University in New York and her team have reported a breakthrough: a partial skeleton of a male P. boisei individual from a site near Lake Turkana, Kenya, dated to about 1.5 million years ago.
The discovery includes a pair of hands, a skull, and some foot bones. Team member Carrie Mongle, also at Stony Brook University, notes that compared to earlier hominins, the hand features more human-like proportions and straighter fingers. "The hand is pretty similar in size to my own, but much more robust," she says. The thumb and finger bones are proportioned like those of modern humans, enabling precision grips for tool use, while other parts are robust like a gorilla's, suggesting exceptional strength. "Shaking hands with this individual would have been noticeably different than shaking hands with your average human," Mongle adds. "They would have been much stronger."
Although no tools were found at the site, Mongle explains, "the hand shows Paranthropus boisei could have formed precision grips similar to ours." This addresses long-standing hesitation to attribute Oldowan tools to P. boisei, especially since Homo habilis remains often appear in the same areas.
Julien Louys at Griffith University in Brisbane, Australia, praises the rarity of such a complete hominin hand. He finds the gorilla-like features most surprising, suggesting behavioral parallels with gorillas alongside human traits. "The evidence suggests that Paranthropus likely used tools, or at least had the right hardware to use tools," Louys says, though debate may persist without direct evidence like a hand clutching a tool.
Amy Mosig Way at the Australian Museum in Sydney notes that even gorillas use simple tools, so P. boisei's capability for freehand percussion—hitting stones together—is plausible. The journal reference is Nature, DOI: 10.1038/s41586-025-09594-8.