The last common ancestor we shared with chimps seems to have lived in the eastern Mediterranean -- not in East Africa as generally assumed. This bold conclusion comes from a study of Greek and Bulgarian fossils, suggesting that the most mysterious of all ancient European apes was actually a human ancestor, or hominin. However, other researchers remain unconvinced by the claim.

The first pre-humans were widely believed to have developed in Africa with the lineages of humans and chimpanzees -- our closest living ancestor -- diverging around five to seven million years ago. According to a report from Phys Org, new research has shown that the split may have happened much earlier in eastern Mediterranean.

Led by Madelaine Böhme and Nikolai Spassov, a team of researchers analyzed two specimens of the fossil hominid Graecopithecus freybergi: a lower jaw from Greece and an upper premolar from Bulgaria. They used computer topography to figure out the internal structures of the individuals and found that the roots of premolars are widely fused.

"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," Böhme explained.

The lower jaw from Greece also had additional dental root features, which strongly suggested the species Graecopithecus freybergi is part of the pre-human lineage. Before this study, pre-humans have only been placed in sub-Saharan Africa. Graecopithecus is also several hundred thousand years older than the oldest potential pre-human ever discovered in Africa, so the human lineage may have actually begun in the Mediterranean.

Although scientists agree in the value of the recent study in its analysis of the species, not everyone is convinced that the Graecopithecus could be definitively classified as a hominin with the current data, according to a report from New Scientist.

Sergio Almécija from the George Washington University pointed out that primates are known to evolve similar features independently adding, "Single characters are not reliable to make big evolutionary [claims]."

The research was published in two papers in the journal PLOS ONE.