Early hominin had human-like dexterity and gorilla strength

A pair of hands belonging to an enigmatic ancient hominin that lived around 1.5 million years ago has been found for the first time, revealing that they had gorilla-like strength alongside the dexterity to make tools.

Paranthropus boisei was first discovered by archaeologist Mary Leakey in 1959 at Olduvai Gorge, Tanzania. The skull was found alongside a type of stone tool known as Oldowan and it was claimed the species was the oldest known maker of stone tools. But because no hand fossils had been found, anthropologists couldn’t be sure that P. boisei had made them.

Now, Leakey’s granddaughter Louise Leakey, a palaeontologist at Stony Brook University in New York, and her colleagues have reported the discovery of a partial skeleton of a P. boisei individual from a site near Lake Turkana, Kenya. It includes a pair of hands, a skull and some feet bones from an individual thought to be male.

Compared with earlier hominin species, this hand has more human-like proportions and straighter fingers, says team member Carrie Mongle, also at Stony Brook University. The hand is pretty “similar in size to my own, but much more robust”, she says.

It has features similar to both modern humans and gorillas: for example, the thumb and finger bones are similarly proportioned to our hands, whereas other parts of the hand have much more robust bones, indicating the strength of a gorilla.

“Shaking hands with this individual would have been noticeably different than shaking hands with your average human,” says Mongle. “They would have been much stronger.”

It is now known that earlier hominins made tools, meaning P. boisei wasn’t the earliest. But Mongle says there has always been hesitation to attribute any Oldowan tools to Paranthropus because the remains of Homo habilis, a closer relative of modern humans, are often found in the same area.

“While we don’t have any tools from this new site, the hand shows Paranthropus boisei could have formed precision grips similar to ours,” she says.

Julien Louys at Griffith University in Brisbane, Australia, says the find helps fill in some of the many holes in our knowledge of the anatomy of ancient hominins in general, and Paranthropus in particular. He says the most surprising aspect of the discovery wasn’t the similarity to human hands, but the parts of the fossil that were similar to gorilla hands.

“Behaviourally, they must have had some parallels with gorillas, but obviously also retaining some of our own behaviours,” says Louys.

“Getting a fairly complete hand of a hominin is incredibly rare. The evidence suggests that Paranthropus likely used tools, or at least had the right hardware to use tools, which isn’t too unexpected,” he says.

“I’m sure some people will continue to argue that only our own genus was capable of making more sophisticated lithics [stone tools], and short of finding a hand of Paranthropus clutching an Oldowan artefact, the debate will likely continue,” says Louys.

Even gorillas are known to bang rock-like objects together as tools, says Amy Mosig Way at the Australian Museum in Sydney, so it is no surprise that P. boisei appears to have been capable of this. The more important question is whether stone tool-making was part of their behavioural repertoire, she says.

“What we can say at this stage is that it’s theoretically possible they did perform freehand percussion [hitting stones together],” she says.

Source: Humans - newscientist.com