Paleoanthropologists have made a groundbreaking discovery in northern Kenya: the most complete skeleton of Homo habilis ever found. This ancestor of modern humans roamed the earth over 2 million years ago. The skeleton includes strong arm bones, setting H. habilis apart from later species.
The fossils were first uncovered in 2012 by a team led by Meave Leakey of the Turkana Basin Institute and were announced in 2015. Recent analysis was published in the journal The Anatomical Record.
The skeleton, named KNM-ER 64061, dates back around 2.02 to 2.06 million years. The findings clearly identify it as H. habilis due to the complete set of lower teeth. It features collarbones, upper and lower arm bones, and fragments of a vertebra and pelvis. This makes it not only the most complete H. habilis skeleton but also among the oldest ever discovered. For context, the oldest known H. habilis skeleton, found in Ethiopia, dates back 2.33 million years.
Fred Grine, a paleoanthropologist and co-author of the study, emphasized the significance of this discovery. He noted there are only three other incomplete skeletons of this pivotal species. Analyzing H. habilis is crucial for understanding early human evolution. This species is a links between older australopithecines—which include the famous fossil “Lucy”—and Homo erectus, a more familiar ancestor that spread globally.
Research findings indicate that the arm bones of H. habilis are similar to other early Homo specimens and some australopithecines. Specifically, it had a longer forearm and thicker arm bones than H. erectus.
According to the researchers, the length of KNM-ER 64061’s humerus suggests the individual was about 5 feet 3 inches tall and weighed around 67.7 pounds. These traits show that H. habilis had proportions resembling those of australopithecines, being shorter and lighter than H. erectus.
While its arm structure suggests some ability for climbing, it’s unclear if H. habilis was fully arboreal, meaning it may have used trees more like earlier species or adapted to a more ground-based lifestyle.
Ashley Hammond, another paleoanthropologist involved in the study, called attention to the long and robust arms of this newly discovered skeleton. Yet, the shape of the lower limbs remains uncertain. The pelvis fragments hint that H. habilis may have walked more like H. erectus, which adds another layer of intrigue to its evolutionary significance.
This find could help scientists better understand the variety of hominin species living in East Africa between 2.2 million and 1.8 million years ago. Research indicates that four hominin species, including Paranthropus boisei, H. habilis, and H. erectus, coexisted in this region. As such, the relationship between H. habilis and H. erectus raises questions about our family tree.
In a world flooded with fascinating discoveries, this skeleton offers a fresh perspective on our distant relatives and the evolution of our species. For further reading on this topic and to deepen your understanding of human ancestry, check out resources from the Smithsonian Institution.
This recent change in our understanding of H. habilis emphasizes how the past continually reshapes our views of human evolution.
