A 10-million-year-old jaw bone recently unearthed in Kenya may have belonged to a new species, which is the last common ancestor of gorillas, chimpanzees and humans.

A team of researchers from Kenya and Japan found the jaw fragment in volcanic mud flow deposits in northern Kenya. The jaw, with incisor, canine and molar teeth, is so different from previous finds that researchers have named the creature Nakalipithecus nakayamai and put it under a different genus Hominid. The discovery may prove to be a missing link in the primate evolution, since it gives credence to the hypothesis that the evolution from ape to human may have taken place entirely in Africa. Prior to this, there has been little evidence of fossils dating between 7 million and 13 million years ago in Africa. Hence, experts believed that the apes that eventually gave rise to humans had left Africa for Asia and Europe, only to return much later.

The finding also suggests that gorillas, chimps and orangutans, have originated from the Hominids. The search is now on for additional fossils to substantiate the new theory.