Reconstruction of the skull from the combination of finds. © Photo by Fred Spoor
Read aloud About two million years ago, two other species of the genus Homo existed in East Africa at the same time as Homo erectus, which is regarded as the direct ancestor of modern man. This is confirmed by new fossil finds from Kenya. It is a facial bone, a complete lower jaw and a part of a second lower jaw. They show the same characteristics as a former hominid find, whose assignment to a species of its own was previously controversial. This debate is now over, say the researchers around Meave and Louise Leakey of the Turkana Basin Institute in Nairobi. For a long time Homo erectus was considered the only primal representative of the genus Homo. This early man developed about two million years ago and populated parts of Africa, Asia and Europe. But then researchers in East Africa found fossils that had a similar age, but differed in their anatomical properties of the known H. erectus fossils. This parallel human form was called Homo habilis.

As early as 1972, another mysterious fossil was discovered near Lake Turkana in Kenya. It bears the name KNM-ER 1470, short? 1470 ". It was an edentulous skull without a jaw, which seemed to be distinguished by its unusual morphology of all other hominid finds: He had a flat face and a comparatively large volume of the brain. This triggered a long-standing debate among anthropologists: some saw in the unusual morphology only gender differences or a natural degree of variation within a species. Others assigned the skull to a species of their own called Homo rudolfensis. However, because comparisons were missing, the existence of H. rudolfensis was still on shaky ground.

The trains of their own kind

"For the last 40 years, we have searched for fossils in the sediments around Lake Turkana that confirm the unique features of 1470 and show us what the teeth and lower jaw looked like, " says Meave Leakey. "Now we were finally successful." The new facial bone was discovered in 2008. Now the investigations documented that he has characteristic similarities with the find 1470. display

The facial bone also has a particularly well preserved upper jaw, which still has almost all the molars in place. In turn, the two other new puzzle pieces fit perfectly: The two lower jaw fossils also belong to this hominid form, the researchers say. The three fossils were dated to an age of 1.78 to 1.95 million years. "So the bottom line seems clear that two species of early genus Homo existed on Earth at the same time as Homo erectus, " says co-author Fred Spoor of the Max Planck Institute in Leipzig. The researchers hold so far with name assignments but still subtly back. They want to first clarify whether it remains in the name homo rudolfensis for the now delineated hominid form.

Meave and Louise Leakey (Turkana Basin Institute in Nairobi) et al .: Nature, doi: 10.1038 / nature11322 © science.de? Martin Vieweg

© science.de

Recommended Editor'S Choice