Archaeologists analysed two known specimens of the fossil hominid Graecopithecus freybergi found in Bulgaria and Greece, revealing that common lineage of great apes and humans split several hundred thousand years earlier than hitherto assumed.
According to the researchers the split of the human lineage occurred in the Eastern Mediterranean and not – as customarily assumed – in Africa. Researchers have assumed up to now that the lineages diverged five to seven million years ago and that the first pre-humans developed in Africa. A lower jaw from Greece and an upper premolar from Bulgaria belonging to the fossil hominid Graecopithecus freybergi were analysed. Using computer tomography, researchers visualized the internal structures of the fossils and demonstrated that the roots of premolars are widely fused. According to the scientists, while great apes typically have two or three separate and diverging roots, the roots of Graecopithecus converge and are partially fused – a feature that is characteristic of modern humans, early humans and several pre-humans including Ardipithecus and Australopithecus.
The lower jaw has additional dental root features, suggesting that the species Graecopithecus freybergi might belong to the pre-human lineage. Graecopithecus is several hundred thousand years older than the oldest potential pre-human from Africa, the six to seven million year old Sahelanthropus from Chad. The research team dated the sedimentary sequence of the Graecopithecus fossil sites in Greece and Bulgaria with physical methods and got a nearly synchronous age for both fossils – 7.24 and 7.175 million years before present. As with the out-of-East-Africa theory, the evolution of pre-humans may have been driven by dramatic environmental changes.
(after Wolfgang Gerber, University of Tübingen, Past Horizon & Live Science)