According to a new study, led by University of Texas at Austin anthropologists Gabrielle A. Russo and Liza Shapiro, a 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 anatomical features related to habitual upright, two-legged walking remain exclusively associated with humans and their fossil ancestors.
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“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.”
Here are some of the many theses put forward for human bipedalism.