The Leakey Foundation reveals what we know about the newest proto-human species to be given a name, Australopithecus sediba – and what these guys tell us about the way we learned to walk:
A new hominin species, Australopithecus sediba (Au. sediba), was named by Berger and his colleagues, following the discovery of two partial skeletons just under two million years old, a juvenile male individual– Malapa Hominin 1 (MH1)– and an adult female, Malapa Hominin 2 (MH2). The skeletons are under the custodianship of the University of the Witwatersrand, where they are being kept. Each partial skeleton is more complete than the famous “Lucy,” an Australopithecus afarensis or early hominin species found in 1974 in Ethiopia. Now, 10 years later after the discovery of Malapa, full descriptions of the hominin fossil material, as well as raw measurement data and surface scans of the fossils, available at Morphosource.org, are published in a special issue of the open access journal, PaleoAnthropology.
“The anatomies we are seeing in Australopithecus sediba are forcing us to reassess the pathway by which we became human,” explained co-editor and Leakey Foundation grantee Jeremy DeSilva, an associate professor of anthropology at Dartmouth, and co-author of four of the papers, including ones on the lower limb and computer animation of the walking mechanics.
“Our findings challenge a traditional, linear view of evolution. It was once thought that a fossil species a million years younger than Lucy would surely look more human-like. For some anatomies of Australopithecus sediba, like the knee, that is true. But, for others, like the foot, it is not. Instead, what we’re witnessing here are parallel lineages, illustrating how different hominin experiments were unfolding early in our complex evolutionary history,” explained DeSilva.
The special issue also finds that Au. sediba was well adapted to terrestrial bipedalism or walking on just two feet but also spent significant time climbing in trees, perhaps for foraging and protection from predators.
Video at the link. Full article pdfs (nine of them) in PaleoAnthropology on this page.