Great Ape Fossil May Be Last Ancestor Of Chimps And Humans
May 2, 2013

Fossil Of Ancient Ape Provides Human Evolution Clues

April Flowers for - Your Universe Online

In 2002 a fossil specimen of an ape skeleton was unearthed in Spain. The researchers who discovered the remains assigned it a new genus and species, Pierolapithecus catalaunicus, estimating that the ape lived about 11.9 million years ago. The researchers argued that the ape could be the last common ancestor of modern great apes, which include chimpanzees, orangutans, bonobos, gorillas and humans.

Now a new study led by a University of Missouri integrative anatomy expert has revealed that the shape of the ape´s pelvis indicates that it lived near the beginning of the great ape evolution after the lesser apes started to independently develop but before the great ape species began to diversify.

The international team was led by Ashley Hammond, a Life Sciences Fellow in the MU Department of Pathology and Anatomical Sciences, and included members from the Autonomous University of Barcelona, the University of Turin and Stony Brook University. Using a tabletop laser scanner attached to a turntable, Hammond was the first to examine the pelvis fragment. The scanner allowed Hammond to capture detailed surface images of the ape fossil, providing her with a 3D model to compare to the pelvic anatomy of living species.

A report on the findings of this study will be published in an upcoming issue of the Journal of Human Evolution.

The fossil´s ilium, the largest bone of the pelvis, is wider than that of Proconsul nyanzae, a more primitive ape that lived about 18 million years ago. The team believes the wider pelvis is related to the greater lateral balance and stability that the ape required to use its forelimbs. Because the fingers of the Pierolapithecus catalaunicus are unlike those of modern great apes, however, the evolutionary history of the great apes might be different than originally hypothesized.

Pierolapithecus catalaunicus seemed to use a lot of upright behaviors such as vertical climbing, but not the fully suspensory behaviors we see in great apes alive today,” Hammond said. “Today, chimpanzees, orangutans, bonobos and gorillas use forelimb-dominated behaviors to swing below branches, but Pierolapithecus catalaunicus didn´t have the long, curved finger bones needed for suspension, so those behaviors evolved more recently.”

The hunt for fossils needs to continue in order to better understand the evolution of the great apes of Africa.

“Contrary to popular belief, we´re not looking for a missing link,” Hammond said. “We have different pieces of the evolutionary puzzle and big gaps between points in time and fossil species. We need to continue fieldwork to identify more fossils and determine how the species are related and how they lived. Ultimately, everything is connected.”