A 7-million-year-old tooth found in Bulgaria has shown that hominids, or humanity's ape ancestors, were still roaming the continent 2 million years later than previously thought.

On Wednesday, scientists from Bulgaria, France and Germany published their findings of the pre-molar tooth found near the town of Chirpan, Bulgaria in the journal Human Evolution.

"The latest data have shown that contrary to the hominids in Western and Central Europe (with the exception of the insular Oreopithecus), hominids from the Eastern Mediterranean may have lived up to 8 to 7.5 [million years ago], preadapted to the more open biotopes of the Balkan-Iranian zoographic province," the team wrote.

Previously, the most recent example of hominid in Europe was the Ouranopithecus macedonensis found in Greece and estimated at 9.2 million years old.

Madelaine Böhme, one of the paper's co-authors and professor of anthropology at the University of Tübingen told Deutsche Welle that the find represented some of the first evidence that hominids living outside of Africa between 7 million and 9 million years ago could have contributed to the evolution of modern humans, or Homo sapiens.

Previously, she explained, the consensus was that while hominids had existed in Europe, they had simply died off, and become extinct. But now, she said, this find fills a gap in the fossil record for hominids in this period and may suggest that European hominids eventually migrated back to Africa.

The period between 7 million and 10 million years ago is very bleak in the fossil record in Africa, she said, with bi-pedal hominids becoming more common starting at around 6 million years ago.

2 million years later

Great apes in Europe were assumed to have become extinct at least 9 million years ago when the terrain transformed from jungle to more of a savannah-type prairie, with scarcer year-round foraging options for fruit.

The find was part of a larger dig that grew out of a quarry in the Azmaka region of Bulgaria. Researchers had already been working the area for several years after other fossils were discovered as a result of a new road being built through the area.

The molar had been discovered in Upper Miocene fluvial sediments by personnel from the National Museum of Natural Science in Sofia, Bulgaria. The Miocene epoch lasted from 23 million years ago until 5.3 million years ago, a period thought to have been characterized by a generally cooling climate as the world headed towards a series of Ice Ages.

In the same layer of sediment as the remains, the scientists found other fossils that suggested savannah-inhabitants, such as the ancestors of antelope, rhinoceros, saber-toothed cats and elephants.

Eating habits

One conclusion drawn by the researchers is that these hominids were able to adapt to the changing environment.

Electron microscope analysis of the well-worn tooth revealed that it had been used to chew harder objects such as grass, seeds and nuts - fare also associated with later African hominids such as "Lucy" or Australopithecus, dating from approximately 4 million years ago.

"These were eating habits that were prerequisite for survival in a savannah-type environment," Böhme told Deutsche Welle.

The researchers were able to draw a lot of conclusions based on one tooth, but Böhme was quick to admit she would have liked more to work with.

"We need more fossils, we need a whole skeleton!" she laughed. "That would be the best, of course."

She added that anthropology as a whole need to re-think where exactly the origins of modern humans are.

"There is increasing evidence, however, that a significant part of human evolution happened outside Africa, in Europe and western Asia," she said.

Author: Stuart Tiffen
Editor: Cyrus Farivar