Extinct ancient ape did not walk like a human, study shows

Jul 25, 2013

According to a new study, led by University of Texas at Austin anthropologists Gabrielle A. Russo and Liza Shapiro, the 9- to 7-million-year-old ape from Italy did not, in fact, walk habitually on two legs.

The findings refute a long body of evidence, suggesting that Oreopithecus had the capabilities for bipedal (moving on two legs) walking.

The study, published in a forthcoming issue of the Journal of Human Evolution, confirms that related to habitual upright, two-legged walking remain exclusively associated with humans and their fossil ancestors.

"Our findings offer new insight into the Oreopithecus locomotor debate," says Russo, who is currently a postdoctoral research fellow at Northeast Ohio Medical University. "While it's certainly possible that Oreopithecus walked on two legs to some extent, as apes are known to employ short bouts of this activity, an increasing amount of anatomical evidence clearly demonstrates that it didn't do so habitually."

As part of the study, the researchers analyzed the fossil ape to see whether it possessed lower spine anatomy consistent with bipedal walking. They compared measurements of its lumbar vertebrae (lower back) and (a triangular bone at the base of the spine) to those of modern humans, fossil hominins (extinct bipedal ), and a sample of mammals that commonly move around in trees, including apes, sloths and an extinct lemur.

The lower spine serves as a good basis for testing the habitual bipedal locomotion hypothesis because lumbar vertebrae and sacra exhibit distinct features that facilitate the transmission of body weight for habitual bipedalism, says Russo.

According to the findings, the anatomy of Oreopithecus lumbar vertebrae and sacrum is unlike that of humans, and more similar to apes, indicating that it is incompatible with the functional demands of walking upright as a human does.

"The lower spine of humans is highly specialized for habitual bipedalism, and is therefore a key region for assessing whether this uniquely human form of locomotion was present in Oreopithecus," says Shapiro, a professor of anthropology. "Previous debate on the locomotor behavior of Oreopithecus had focused on the anatomy of the limbs and pelvis, but no one had reassessed the controversial claim that its lower back was human-like."

Explore further: 11.9 million-year-old fossil of great ape sheds light on evolution

More information: www.sciencedirect.com/science/article/pii/S0047248413001322

Related Stories

It's all in the way we move

Mar 13, 2013

When, how and why modern humans first stood up and walked on two legs is considered to be one of the greatest missing links in our evolutionary history. Scientists have gone to the far ends of the earth – and the wonderful ...

Lucy and Selam's species climbed trees

Oct 25, 2012

Australopithecus afarensis (the species of the well-known "Lucy" skeleton) was an upright walking species, but the question of whether it also spent much of its time in trees has been the subject of much debate, partly becaus ...

Recommended for you

Lemurs match scent of a friend to sound of her voice

9 hours ago

Humans aren't alone in their ability to match a voice to a face—animals such as dogs, horses, crows and monkeys are able to recognize familiar individuals this way too, a growing body of research shows.

Love-shy panda artificially inseminated

19 hours ago

Britain's only female giant panda, Tian Tian, has been artificially inseminated after failing to mate with her male partner Yang Guang, Edinburgh Zoo said Tuesday.

User comments : 0

More news stories

Patent talk: Google sharpens contact lens vision

(Phys.org) —A report from Patent Bolt brings us one step closer to what Google may have in mind in developing smart contact lenses. According to the discussion Google is interested in the concept of contact ...

Wireless industry makes anti-theft commitment

A trade group for wireless providers said Tuesday that the biggest mobile device manufacturers and carriers will soon put anti-theft tools on the gadgets to try to deter rampant smartphone theft.