A 2.6-million-year-old jawbone discovered in Ethiopia's Afar region marks the first known fossil of the robust hominin Paranthropus from that area. Found about 1,000 kilometers north of previous sites, the specimen suggests this early human relative was more adaptable and widespread than previously thought. Led by University of Chicago paleoanthropologist Zeresenay Alemseged, the discovery challenges long-held views on hominin competition and evolution.
The fossil, a partial jaw from the Mille-Logya research area, dates back 2.6 million years and ranks among the oldest Paranthropus specimens. Previously, Paranthropus fossils were absent from the Afar, despite abundant remains of other hominins like Ardipithecus, Australopithecus, and Homo. This gap had puzzled researchers, leading some to speculate that Paranthropus was confined to southern regions due to a specialized diet or inability to compete with more versatile Homo species.
Alemseged, the Donald N. Pritzker Professor of Organismal Biology and Anatomy, dismisses those notions. "Neither was the case: Paranthropus was as widespread and versatile as Homo and the new find shows that its absence in the Afar was an artifact of the fossil record," he stated. The team recovered fragments from the site and analyzed them using high-resolution micro-CT scanning in Chicago, revealing details about the jaw's structure.
"It's a remarkable nexus: an ultra-modern technology being applied to a 2.6-million-year-old fossil to tell a story that is common to us all," Alemseged noted. The find indicates Paranthropus, often called the 'nutcracker' for its massive jaws and thick-enamel molars, could exploit diverse food sources and coexist with early Homo members.
This discovery broadens understanding of hominin evolution following the human-chimpanzee split around 7 million years ago. It prompts reevaluation of competitive dynamics among groups: facultative bipeds like Ardipithecus, habitual bipeds such as Australopithecus, obligate bipeds in Homo, and robust forms like Paranthropus.
"The new discovery gives us insight into the competitive edges that each group had, the type of diet they were consuming, the type of muscular and skeletal adaptations that they had," Alemseged explained. The research, approved by Ethiopian authorities and funded by the Hearst family and the University of Chicago, appears in the January 2026 issue of Nature under the title "First Afar Paranthropus fossil expands the distribution of a versatile genus." Co-authors include Fred Spoor, Denné Reed, and others.