Anthropologists have discovered jawbone fragments which may belong to the last common ancestor of great apes and humans.

In 2005, a Kenyan and Japanese research team discovered a jawbone fossil that is believed to be part of a previously unknown species of great ape. This creature could be the last common ancestor shared by gorillas, chimpanzees and humans. The species is between the size of a female gorilla and female orangutan.

Researchers say the 10-million-year-old jawbone may prove to be the “missing link,” the key split in the evolutionary chain that scientists have been searching for. Humans split from other primates in terms of evolutionary development millions of years ago. Exactly when this split occurred is one of the great mysteries of science.

The jaw fragment was found with 11 intact teeth buried in volcanic mudflow deposits in the northern Nakali region of Kenya. Scientists say it dates back about 9.8 million years.

The Nakali region of Kenya is located in East Africa’s Rift Valley, an area long regarded by anthropologists as “the cradle of humankind.”

 [Source: USA Toda; New York Times; Discover]