Analysis of a fossilized femur bone discovered in Bulgaria suggests that the oldest known human ancestor may have walked upright as early as 7.2 million years ago. The discovery sheds new light on the evolution of bipedalism and challenges the dominant theory of an African origin for the hominin lineage. The find, attributed to the species Graecopithecus, indicates that a key evolutionary stage may have occurred in Southern Europe, not Africa. Scientists, however, emphasize that this is a single find requiring further study.

Bipedalism Older Than Thought

Research on a femur bone found in Azmaka, Bulgaria, suggests that an ancestor of the species Graecopithecus may have moved on two legs as early as 7.2 million years ago. This is several million years earlier than the famous Lucy (Australopithecus afarensis) from Africa, dated to about 3.2 million years ago.

European, Not African Origin?

The discovery challenges the long-held theory that the hominin lineage originates exclusively from Africa. The Graecopithecus fossil, previously known from teeth found in Greece and Bulgaria, points to the possibility of a European origin for the key evolutionary branch leading to humans.

Research Methodology and Controversy

Scientists used advanced 3D imaging techniques to analyze the internal structure of the femur bone. The discovery has been met with a cautious reaction from parts of the paleoanthropological community, which points to the need to find more fossils to confirm the revolutionary thesis about bipedalism and European origin.

Significance for the Evolutionary Tree

If the thesis is confirmed, Graecopithecus could be the oldest known representative of the subfamily Homininae, which includes humans, chimpanzees, and gorillas. This would mean that the split between the hominin and chimpanzee lineages could have occurred in the Mediterranean region.

A significant paradigm shift may be underway in paleoanthropology. Analysis of a fossilized femur bone, discovered in the town of Azmaka in Bulgaria, indicates that the species Graecopithecus may have walked upright around 7.2 million years ago. This discovery, described in articles published between March 5 and 7, 2026, pushes the possible origins of bipedalism – a key feature of the human evolutionary line – back by several million years compared to earlier evidence from Africa. The bone, found earlier, was subjected to modern micro-tomographic studies, which revealed a characteristic internal structure that, according to scientists, supports the hypothesis of bipedalism. The debate about the cradle of humanity has been ongoing for decades, with the dominant "Out of Africa" theory throughout most of the 20th and 21st centuries placing the origins of the hominin lineage on the African continent. Key fossils, such as the skeleton of "Lucy" (Australopithecus afarensis) found in Ethiopia and dated to about 3.2 million years ago, formed a strong pillar of this narrative. Discoveries in Asia and Europe, such as fossil apes from the Miocene period, have always introduced a note of doubt regarding Africa's exclusivity. The latest research suggests that Graecopithecus freybergi, previously known mainly from teeth, may represent the oldest known ancestor of the lineage leading to humans, chimpanzees, and gorillas (subfamily Homininae). If this interpretation is confirmed, it would mean that the split between the hominin and chimpanzee lineages could have occurred in the Mediterranean region, not in Africa. „This discovery could revolutionize our understanding of the beginnings of humanity.” — Professor Madelaine Böhme, geologist and paleontologist However, German and Bulgarian scientists involved in the project emphasize that this is a preliminary analysis based on a single, incomplete skeletal element. 7.2 mln lat — Estimated age of the Graecopithecus femur boneThe scientific community's reaction to these reports is mixed. Some researchers admit the evidence is intriguing and deserves serious consideration but call for caution. Paleoanthropology knows many cases where single finds initially shook established theories, only to later turn out to be misinterpreted. More fossils are needed – especially pelvis, vertebrae, and other limb bones – to definitively confirm the bipedalism of Graecopithecus. Without them, the hypothesis will remain speculation, albeit scientifically stimulating. Regardless of the final verdict, the discovery in Bulgaria will certainly revive the debate about the geographical origin of our evolutionary line and force scientists to re-examine Miocene-era finds from Europe.

Mentioned People

  • Madelaine Böhme — Geologist and paleontologist involved in the Graecopithecus femur bone research.