Fossil Analysis Provides Insight Into Ape Evolution

A study from University of Missouri debunks the idea that a fossil found in 2002 belonged to the last ancestor of modern-day great apes that include chimpanzees, orangutans, bonobos, gorillas and humans. Instead, researchers of the new study argue that Pierolapithecus catalaunicus (that lived about 11.9 million years back) might have lived at a time when the great apes were evolving, but hadn't yet diversified into various species.

Researchers reached their conclusion after studying the pelvis bone of the fossil. Ashley Hammond, a Life Sciences Fellow in the MU Department of Pathology and Anatomical Sciences, used a tabletop laser scanner attached to a turntable to get a 3-D image of the specimen. She then used this image to compare the pelvis bone of the fossil to the pelvis bones of the ape species living today.

The ilium, or the largest pelvic bone of the Pierolapithecus catalaunicus, was found to be wider than that of another primitive species of ape that lived about 18 million years ago, called Proconsul nyanzae. The pelvis size is related to the ape's movement. The research also showed that the forefingers of the fossil were different from the forefingers of modern apes, suggesting that the apes may have evolved in a different way than currently speculated.

"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. 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," Hammond explained.

She added that further research is required to find how apes evolved.           

"Contrary to popular belief, we're not looking for a missing link," Hammond said in a news release. "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."

The study is published in the Journal of Human Evolution.