The National Museums of Kenya (NMK) has unearthed yet another new fossil discovery Tuesday in the Nakali region of Kenya 40 kilometers from Maralal town.

The new species "Nakalipithecus Nakayamai" dates back to 9.8 million years ago and is believed to be a new genus of the great ape.

This comes only four months after the announcement of the discovery of two fossils, a Homo Habilis relic dating back 1.44 million years and Homo Erectus dating back 1.55 million years, which were found seven years ago East of Lake Turkana.

The new discovery is a fossil jaw and 11 isolated teeth, which according to researchers, represented a new species of Great Ape.

In a press invite, the researchers said the discovery could be the missing link in the evolution theory, and was the most likely ancestor of the African great apes and humans.

"Based on this particular discovery, we can comfortably say we are approaching the point at which we can pin down the so-called missing link," said Frederick Manthi, Senior Research Scientist at the National Museums of Kenya.

"We have to find more fossils from a cross-section of sites to sustain that particular theory," he told a news conference.

Christened Nakalipithecus nakayamai, the new species fed on nuts, seeds and fruit.

The new species, was discovered by researchers from NMK and Japanese universities along the volcanic mud flow deposits in the Nakali region of Central Kenya.

The joint palaeontological project placed the age of the specimens at between 9.80 and 9.88 million years, which they said was a crucial period when humans and the African great apes [chimpanzees and gorilla] are believed to have diverged. 

"The teeth were covered in thick enamel and the caps were low and voluminous, suggesting that the diet of this ape consisted of a considerable amount of hard objects, like nuts or seeds, and fruit," Yutaka Kunimatsu at Kyoto University's Primate Research Institute said.

"It could be positioned before the split between gorillas, chimps and humans," he added.

Kunimatsu said it was hard to determine what Nakalipithecus nakayamai looked like.

"We only have some jaw fragments and some teeth ... but we hope to find other body parts in our future research. We plan to go back next year. We will try to find bones below the neck to tell us how the animal moved," he said.

Published in the latest issue of the Proceedings of the National Academy of Sciences, the finding is significant as it gives credence to the theory that the evolution from ape to man may have taken place entirely in Africa.

Prior to this finding, there had been so little fossil evidence in Africa dating between 7 to 13 million years ago that some experts began to surmise that the last common ancestor left Africa for Europe and Asia, and then returned later.

But Kunimatsu said the findings suggested that the ancestor of African great apes and humans likely evolved in Africa.

"Now, we have a good candidate in Africa. We do not need to think the common ancestor came back from Eurasia to Africa. I think it is more likely the common ancestor evolved from the apes in the Miocene in Africa," he said.

The Miocene is a period of time extending from 23.03 million to 5.33 million years ago.

"Some apes (then) left Africa and migrated to Eurasia. They then became orangutans in Southeast Asia. Today's orangutan evolved from the apes that left Africa," he said.

The researchers said the fossils of large apes in Eastern Africa dating back between five and eleven million years were rare.

They said this new discovery would strengthen claims that suggest Kenya is indeed the cradle of mankind.