Fossilised ape skeleton could be evolution's missing link

An extinct ape that lived 13 million years ago has been identified as the leading contender for the title of last common ancestor of humans and all great apes alive today.

An extinct ape that lived 13 million years ago has been identified as the leading contender for the title of last common ancestor of humans and all great apes alive today.

Scientists have found a fossilised partial skeleton of the ape at a site near Barcelona in Spain and have concluded that it could be the species that gave rise to all subsequent great apes, including orang-utans, gorillas and chimps, as well as humans.

The new species, called Pierolapithecus catalaunicus, bears many of the anatomical hallmarks of present-day apes yet retains some primitive features which suggest it lies at the root of all human and great ape evolution.

If it were not itself the last common ancestor of all great apes and humans, then P. catalaunicus was closely related to it, said Salvador Moya-Sola, who led the team from the Miguel Crusafont Institute of Palaeontology in Barcelona.

"This probably is very close to the last common ancestor of great apes and humans ... The importance of this new fossil is that for the first time all the key areas that define modern great apes are well-preserved," Professor Moya-Sola said.

Although the ape fossils were found in what is now Spain, it almost certainly lived in Africa as well, where the earliest humans evolved, he said.

P. catalaunicus was probably a fruit-eater, weighed about 35kg (77lbs) and lived mostly in trees, although its short fingers meant that it was not as agile as chimpanzees which can hang easily from branches using their long, curved hands.

A study of the creature's rib cage and chest, published in the journal Science, shows that it had diverged significantly from the basic body plan of Old World monkeys to adopt a more upright, ape-like stance.

Instead of having a rounded ribcage with shoulder blades attached to the sides - like monkeys - P. catalaunicus had a wider, flatter chest with shoulder blades lying flat against its back, similar to modern apes and humans.

Meike Köhler, a member of the research team, said that although the concept of a "missing link" was misunderstood, the extinct ape filled a gap in the early evolution of humans and apes.

"I would call it a missing link ... This does not mean that just this individual, or even this species, exactly this species, must have been the species that gave rise to everything else which came later in the great ape tree. But it is, if not the species, most probably a very closely related species that gave rise to it," she said.

R Brooks Hanson, deputy editor of physical sciences at Science, said that the Old World monkeys of Africa and a group of primates that evolved into apes split off from one another about 25 million years ago. About 14 to 16 million years ago, gibbons split off from the rest of the great apes, and P. catalaunicus lived after this point, before orang-utans split off at about 10 or 11 million years ago.

" P. catalaunicus, or its close relative, may have been the last common ancestor of all living great apes, or close to that ancestor," Dr Hanson said. "Although this group includes humans, it's important to remember that we've had millions of years of evolution since then," Mr Hanson said.