A 1.34-million-year-old partial skeleton of the Plio-Pleistocene hominin Paranthropus boisei – including arm, hand, leg and foot fragments – found at the Olduvai Gorge site in Tanzania represents one of the most recent occurrences of the hominin before its extinction in East Africa.

Paranthropus boisei was a long-lived species of archaic hominin that first evolved in East Africa about 2.3 million years ago.

The first skull of Paranthropus boisei, dated to 1.75 million years old, was discovered in 1959 at Olduvai by the anthropologist Dr Mary Leakey. A number of hominin’s skull fossils have been discovered over the years, but the build and skeletal adaptations of the rest of the Paranthropus boisei‘s body have been unknown, until now.

During Olduvai excavations in 2010-2011, anthropologist Dr Charles Musiba of the University of Colorado Denver with colleagues unearthed the partial skeleton of a large adult individual who is represented by various teeth and skeletal parts.

“This is the first time we’ve found bones that suggest that this creature was more ruggedly built – combining terrestrial bipedal locomotion and some arboreal behaviors – than we’d previously thought. It seems to have more well-formed forearm muscles that were used for climbing, fine-manipulation and all sorts of behavior,” said Dr Musiba, who is a co-author of the paper published in the journal PLoS ONE.

“We are starting to understand the physiology of these individuals of this particular species and how it actually adapted to the kind of habitat it lived in. We knew about the kind of food it ate – it was omnivorous, leaning more toward plant material – but now we know more: how it walked around and now we know it was a tree climber.”

“The size of the arm bones suggests strong forearms and a powerful upper body. It’s a different branch on our ancestry tree. It came later than the other hominins, so the question now is what happened to it? We’re going to do more work on biomechanics and see what else this creature was doing.”

The Paranthropus boisei individual likely stood 1.0 to 1.4 m tall and possessed a robust frame.

“We know that it was very strong. It’s unprecedented to find how strong this individual was. The stronger you are the more adaptive you are,” Dr Musiba said.

______

Domínguez-Rodrigo M et al. 2013. First Partial Skeleton of a 1.34-Million-Year-Old Paranthropus boisei from Bed II, Olduvai Gorge, Tanzania. PLoS ONE 8 (12): e80347; doi: 10.1371/journal.pone.0080347