November 18, 2004. Copyright 2004, Graphic News. All rights reserved

Skeleton of first great ape uncovered
By Mark Rutter

LONDON, November 18, Graphic News:  The Journal Science has reported the discovery of a partial skeleton of a new species of great ape that promises to fill some of the gaps in our knowledge of human evolution.

Between 22 million and 5.5 million years ago, a period known as the Miocene, around 100 different ape species are thought to have roamed modern-day Europe, Asia and Africa. The apes were able to flourish in the lush subtropical forest cover, giving rise to an abundant source of fruit. Although most of these apes are now extinct, it was then that the common ancestor of the great apes -- orangutans, chimpanzees and gorillas -- and man evolved from primitive monkeys.

As the fossil record of the Miocene is incomplete, piecing together the evolutionary history has proven to be difficult and contentious, with a number of conflicting theories put forward. Many of the skeleton fossils originating from this time lack several vital parts, and usually consist only of jaws and teeth, giving little indication of posture and movement.

The new species, Pierolapithecus catalaunicus, named after the village near Barcelona, Spain, where it was found, is the best preserved and most complete skeleton yet found from this period. Salvador Moyˆ-Solˆ, of BarcelonaÕs Institut de Paleontologia, and colleagues believe it to be between 12.5 and 13 million years old. Scientists who examined its skull and the bones of the chest, lumbar region of the back and the wrist say that it appears to be either the common ancestor of great apes, or at least very closely linked to it.

The shape of the face is important in differentiating apes. Great apes have several common features that differentiate them from more primitive monkeys, including a flattened nose with wide nostrils. These facial characteristics were present in Pierolapithecus, although it did retain a monkey-like profile to the skull.

Other features of the skeleton give clues to how Pierolapithecus got around. The chest is ape-like, being broad and shallow, compared with the narrow deep chest of monkeys, enabling better upper limb movement for climbing up trees. Flexible wrists would have allowed it to hang easily from branches, further improving its vertical climbing ability. This is particularly interesting as it is the earliest time that the ape-like wrist has been seen. These characteristics are also indicative of upright walking, as is the relatively rigid spine in the lumbar region.

Although the skeleton did show a few monkey-like features, there is no doubt that the overwhelming characteristics are those of a great ape. On the basis of this, the researchers were able to conclude that the split between great apes and monkeys occurred around 11-16 million years ago, a finding backed up by studies of the genetics of the various groups of modern apes.
/ENDS