Some species of hominids, a family of primates dating back to the early Miocene, who lived in East Africa about 1.5 million years ago could use tools with their hands, according to a new study recently published in Nature by researchers at Stony Brook University. This is a question that has been debated at length until today, because the fossils known until now did not allow us to precisely reconstruct the anatomy of the hands of these our ancestors. But the recent discovery of new fossil remains reshuffles the cards on the table, allowing us to understand the evolution of hands.
During the excavation campaign (2019-2021) carried out by an American research group led by Carrie Mongle on the shores of Lake Turkana, in Kenya, the fossil remains of an individual of Paranthropus boiseia species of hominid that lived between 2.6 and 1.2 million years ago. The genre Paranthropus (from Greek, meaning “next to man”) was a genus of hominids that coexisted with the genus Australopithecus (from which our species probably derives) for a certain period of time, constituting a sort of parallel evolutionary line that became extinct around 1 million years ago. The individual, who lived about 1.5 million years ago and named KNM-ER 101000, has the bones of the hands and feet very well preservedallowing scholars to precisely observe the anatomy of the limbs, which has been debated until now.
The morphology of the hands of Paranthropus boisei suggests that in fact these were already very similar to those of subsequent hominid species. The proportion between the length of the thumb and the size of the hand is already basically “human”, and its anatomical conformation suggests how in theory it could have allowed us to hold something, even if not in a stable and precise way like we do. However, there are also substantial differences. Some features of the hand resemble those of the gorilla, which suggests how probably Paranthropus boisei was a good tree climber.
The study of the conformation of the bones of the feet was also particularly important; in fact, it was demonstrated that the foot had already morphologically adapted to a bipedal gait, which did not necessarily preclude the possibility of climbing trees.
