The newly-discovered fossil — a 2.6-million-year-old partial lower jaw found in the Afar region of Ethiopia — represents the first known specimen of Paranthropus ever discovered there and is among the oldest remains attributed to this genus anywhere in Africa. The discovery is reshaping paleoanthropologists’ understanding of one of humanity’s ancient relatives, suggesting that a robust branch of early hominins was far more widespread and adaptable than previously believed.
Paranthropus boisei. Image credit: © Roman Yevseyev.
Labeled MLP-3000, the new Paranthropus fossil was found in the Mille-Logya research area.
The specimen consists of an edentulous mandibular corpus with preserved tooth roots and an associated partial molar crown.
Geological and magnetostratigraphic evidence place the fossil securely between roughly 2.9 and 2.5 million years ago, during a period marked by significant environmental change in eastern Africa.
“If we are to understand our own evolutionary trajectory as a genus and species, we need to understand the environmental, ecological, and competitive factors that shaped our evolution,” said University of Chicago’s Professor Zeresenay Alemseged.
“This discovery is so much more than a simple snapshot of Paranthropus’ occurrence: it sheds fresh light on the driving forces behind the evolution of the genus.”
Until now, Paranthropus fossils had been documented from southern Ethiopia to South Africa, but not from the Afar region.
The absence was puzzling given the region’s exceptionally rich fossil record, which spans about 6 million years and includes key finds of Australopithecus and early Homo.
The new discovery indicates that Paranthropus had a broader geographic range from its earliest known appearance than previously recognized.
“We strive to understand who we are and how we became to be human, and that has implications for how we behave and how we are going to impact the environment around us, and how that, in turn, is going to impact us,” Professor Alemseged said.
“In the fossil record, the human lineage is represented by over 15 hominin species that generally fit into four groups: facultative bipeds, habitual bipeds, obligate bipeds, and robust hominins.”
“Hundreds of fossils representing over a dozen species of Ardipithecus, Australopithecus, and Homo had been found in the Afar region of northern Ethiopia, so the apparent absence of Paranthropus was conspicuous and puzzling to paleoanthropologists, many of whom had concluded the genus simply never ventured that far north.”
“While some experts suggested that dietary specialization restricted Paranthropus to southern regions, others hypothesized that this could have been the result of Paranthropus’ inability to compete with the more versatile Homo,” he added.
“However, 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.”
Anatomical analysis shows that the jaw combines hallmark features of Paranthropus, including a particularly robust mandibular corpus and very large postcanine teeth, with traits considered more primitive and seen in earlier hominins.
This mosaic of characteristics led the researchers to attribute the fossil conservatively to Paranthropus sp., without assigning it to a specific species.
According to the authors, the context of the find is as significant as the fossil itself.
The Mille-Logya area preserves sediments from a poorly sampled interval between about 3.0 and 2.4 million years ago, a time when climates across eastern Africa were becoming more open and grassland-dominated.
Associated animal fossils indicate shifting habitats, suggesting that Paranthropus was able to occupy a range of environments rather than being confined to a narrow ecological niche.
The presence of Paranthropus in the Afar also means that multiple hominin lineages co-existed in the region during the Late Pliocene.
Fossils of early Homo and Australopithecus of similar ages are already known from nearby sites, underscoring a period of unexpectedly high diversity near the dawn of the genus Homo.
By extending the known range of Paranthropus more than 1,000 km north of its previously recognized limits, the find challenges long-held assumptions about the ecology and dispersal of these robust hominins.
“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, whether they were using stone tools or not — all parts of their adaptation and behavior that we are trying to figure out,” Professor Alemseged said.
“Discoveries like this really trigger interesting questions in terms of reviewing, revising, and then coming up with new hypotheses as to what the key differences were between the main hominin groups.”
The discovery is reported in a paper published today in the journal Nature.
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Zeresenay Alemseged et al. First Afar Paranthropus fossil expands the distribution of a versatile genus. Nature, published online January 21, 2026; doi: 10.1038/s41586-025-09826-x
