A new study led by Dr Salvador Moya-Sola from the Universitat Autònoma de Barcelona, Spain, is the first to examine the pelvis fragments of an early hominid called Pierolapithecus catalaunicus.

Dr Moya-Sola with colleagues discovered the fossil specimen of Pierolapithecus in Spain in 2002. They estimated that the hominid lived about 11.9 million years ago, arguing that it could be the last common ancestor of modern great apes: chimpanzees, orangutans, bonobos, gorillas and humans.

According to the new analysis published in the Journal of Human Evolution, the shape of the specimen’s pelvis indicates that Pierolapithecus lived near the beginning of the great ape evolution, after the lesser apes had started to develop separately but before the great ape species began to diversify.

The team members used a tabletop laser scanner attached to a turntable to capture detailed surface images of the fossil, which provided them with a 3-D model to compare the Pierolapithecus pelvis anatomy to living species.

“The ilium – the largest bone in the pelvis – of the Pierolapithecus is wider than that of Proconsul nyanzae, a more primitive ape that lived approximately 18 million years ago. The wider pelvis may be related to the ape’s greater lateral balance and stability while moving using its forelimbs. However, the fingers of the Pierolapithecus catalaunicus are unlike those of modern great apes, indicating that great apes may have evolved differently than scientists originally hypothesized,” said study first author Dr Ashley Hammond from the University of Missouri School of Medicine.

“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.”

The researchers continue searching for fossils to further explain the evolution of the great apes in Africa.

“Contrary to popular belief, we’re not looking for a missing link,” Dr 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.”

______

Bibliographic information: Ashley S. Hammond et al. Middle Miocene Pierolapithecus provides a first glimpse into early hominid pelvic morphology. Journal of Human Evolution, published online March 30, 2013; doi: 10.1016/j.jhevol.2013.03.002