Australopithecus afarensis was one of the longest-lived and best known early human species that originated in Africa.

Previous fossils of this species have all be found in the centre of the Rift Valley in Kenya.

Now, researchers have discovered remains at a settlement on the outskirts of Nairobi suggesting our ancestors roamed much further than we thought.

For the first time, fossils of the the hominid Australopithecus afarensis have been found east of the Rift Valley, showing the species travelled further than we thought . A sculptor's rendering of the species, displayed as part of an exhibition that includes the 3.2 million year old fossilised remains of 'Lucy', is pictured

An international team of paleontologists led by Dr Emma Mbua of Mount Kenya University and Professor Masato Nakatsukasa of Kyoto University found fossilized teeth and forearm bone belonging to an adult male and two infant Australopithecus afarensis.

The fossils were found at an exposure eroded by the Kantis River in Ongata-Rongai, a settlement in the outskirts of Nairobi.

A. afarensis is believed to have lived between 3.7 and 3 million years ago, which has been determined by fossils like the famous 'Lucy' from Ethiopia.

An international team of paleontologists led by Dr Emma Mbua of Mount Kenya University and Professor Masato Nakatsukasa of Kyoto University found fossilized teeth, pictured left, and forearm bone, pictured right, belonging to an adult male and two infant Australopithecus afarensis

The fossils were found at an exposure eroded by the Kantis River in Ongata-Rongai, a settlement in the outskirts of Nairobi, shown on map. So far, all other A. afarensis fossils had been identified from the centre of the Rift Valley, shown on map

THE COMPLEX EVOLUTION OF MAN 55 million years ago - First primitive primates evolve 15 million years ago - Hominidae (great apes) evolve from the ancestors of the gibbon 8 million years ago - First gorillas evolve. Later, chimp and human lineages diverge 5.5 million years ago - Ardipithecus, early 'proto-human' shares traits with chimps and gorillas 4 million years ago - Ape like early humans, the Australopithecines appeared. They had brains no larger than a chimpanzee's but other more human like features 3.9-2.9 million years ago - Australoipithecus afarensis lived in Africa. 3-2 million years ago - Australopithecus africanus lived 2.7 million years ago - Paranthropus, lived in woods and had massive jaws for chewing 2.3 million years ago - Homo habalis first thought to have appeared in Africa 1.85 million years ago - First 'modern' hand emerges 1.8 million years ago - Homo ergaster begins to appear in fossil record 1.6 million years ago - Hand axes become the first major technological innovation 800,000 years ago - Early humans control fire and create hearths. Brain size increases rapidly 400,000 years ago - Neanderthals first begin to appear and spread across Europe and Asia 200,000 years ago - Homo sapiens - modern humans - appear in Africa 40,0000 years ago - Modern humans reach Europe This graphic reveals where A. afarensis is believed to sit in the evolution of other australopiths and homo species. Years are shown along the bottom. The new findings show that Australopithecus could have covered a much greater area than previously thought by 3 million years ago Advertisement

'So far, all other A. afarensis fossils had been identified from the centre of the Rift Valley,' said Professor Nakatsukasa.

'A previous Australopithecus bahrelghazali discovery in Chad confirmed that our hominid ancestor's distribution covered central Africa, but this was the first time an Australopithecus fossil has been found east of the Rift Valley.

'This has important implications for what we understand about our ancestor's distribution range, namely that Australopithecus could have covered a much greater area by this age.'

Analysis revealed the Kantis region was humid, but had a plain like environment with fewer trees compared to other sites in the Great Rift Valley where A. afaransis fossils had previously appeared.

'The hominid must have discovered suitable habitats in the Kenyan highlands.

'It seems that A. afaransis was good at adapting to varying environments,' said Professor Nakatsukasa.

Analysis revealed the Kantis region, at the site pictured, was humid but had a plain like environment with fewer trees compared to other sites in the Great Rift Valley where A. afaransis fossils had previously appeared

Dr Emma Mbua, lead author of the paper, pictured at the excavation site. The Kantis site was first noted in a 1991 geological survey. At that time, a farmer said that he and his family had come across fossilized bones from Kantis in the 1970s, although they did not recognize their importance

The team's survey also turned up masses of mammal fossils, including samples that probably belong to new species of bovids or baboons.

The Kantis site was first noted in a 1991 geological survey. At that time, a farmer said that he and his family had come across fossilized bones from Kantis in the 1970s, although they did not recognize their importance.

Since then, Kantis and other sites have been identified thanks to fossil notifications from the local population.

'Kantis is in the vicinity of Nairobi, a major city,' said Professor Nakatsukasa. 'We hope that the discovery of the new site and the fossils will aid in increasing tourism, and in improving educational awareness of the local community.'

The team's survey also turned up masses of mammal fossils, including an ancient hippo jaw, pictured

Analysis revealed that the Kantis region was humid, but had a plain like environment with fewer trees compared to other sites in the Great Rift Valley. The team's survey also turned up masses of mammal fossils, including a few that probably belong to new species of bovids or baboons. Modern baboon pictured