Ancestors - BBC website

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US and Ethiopian scientists say they have discovered the fossilised

remains of one of the earliest human ancestors.

The research team, working in the north-east of Ethiopia, believe the

remains of the hominid, or primitive human, date back four million

years.

They say initial study of the bones indicates the creature was

bipedal - it walked around on two legs.

The fossils were found just 60km (40 miles) from the site where the

famous hominid Lucy was discovered.

Lucy (Australopithecus afarensis), whose remains were unearthed in

1974, lived 3.2 million years ago and is thought to have given rise

to the Homo line that ended in modern humans.

Like Lucy?

The as yet unnamed fossil creature, found in February at a new site

called Mille in the Afar region of Ethiopia, looks to be an even

earlier hominid cousin.

 

Could the skeleton be even older than Lucy?

The remains include a complete tibia from the lower part of the leg,

parts of the thighbone or femur, ribs, vertebrae, a collarbone,

pelvis and a complete shoulder blade.

" The discovery of 12 early hominid fossil specimens estimated to be

between 3.8 and 4 million years old will be important in terms of

understanding the early phases of human evolution before Lucy, "

Yohannes Haile Selassie told a news conference.

The researchers say the find is significant because, due to the

structure of the ankle bone, the individual almost certainly walked

upright like modern mankind.

" This is the world's oldest [hominid] biped, " claimed Bruce Latimer,

of the Cleveland Museum of Natural History, US, who made the

discovery with his Ethiopian colleague. " It will revolutionise the

way we see human evolution. "

He added: " This skeleton helps us to understand what happened in the

joints, how walking upright occurred, what we never had before. "

The find, one of a series of hominid fossils which are still being

unearthed, held many mysteries, he said.

" It is already clear that the individual was larger than Lucy; it has

longer legs than Lucy... but it is older which is strange. "

Early walkers

The discovery of the remains of at least nine primitive hominids of

similar age to the latest find was announced in January.

Those fossils, which were uncovered at As Duma in the north of

Ethiopia, were mostly teeth and jaw fragments, but also include parts

of hands and feet.

Bipedalism is a crucial aspect of the human form,

palaeoanthropologists believe - but there is a great deal of debate

about when exactly this ability first arose in our lineage.

There is some evidence that two, very much older hominids could walk

upright.

Recent computed tomography (CT) scans of the thighbone of a six-

million-year-old Kenyan creature known as Orrorin tugenensis suggest

it might have had quite a human gait.

And a seven-million-year-old hominid from Chad, known as

Sahelanthropus tchadensis and nicknamed Toumai, may also have been

bipedal. The assessment is based on an analysis of where the animal's

spine would have entered the skull and the position of muscle

attachments on head.