The hominid’s unusual build may place it in humankind’s lineage
A surprising mix of apelike and humanlike features from head to toe supports a controversial contention that a 2-million-year-old member of the human evolutionary family gave rise to the genus Homo, an international team of researchers reports in six papers published April 12 in Science.
Anthropologist Lee Berger of the University of the Witwatersrand in Johannesburg, South Africa, and his colleagues assigned two partial skeletons and other fossils found in a South African cave in 2008 to a species they named Australopithecus sediba. Among the group’s new findings: A. sediba’s teeth suggest that this hominid evolved into a Homo species but had no links to earlier East African hominids often regarded as Homo ancestors. Those hominids include 3.2-million-year-old Australopithecus afarensis, best known for Lucy’s partial skeleton. A. sediba’s relatively long arms were suited to hanging out in trees, consistent with its narrow, apelike upper rib cage. But these hominids also had narrow, humanlike lower rib cages and lower backs that were longer and more flexible than those of people today. A. sediba probably walked awkwardly with its feet rolling inward and slightly pigeon-toed.
S. Churchill et al. The upper limb of Australopithecus sediba. Science. Vol. 340, April 12, 2013, p. 1233477-1. doi: 10.1126/science1233477. [Go to]
D. de Ruiter et al. Mandibular remains support taxonomic validity of Australopithecus sediba. Science. Vol. 340, April 12, 2013, p. 1232997-1. doi: 10.1126/science1232997. [Go to]
J. DeSilva et al. The lower limb and mechanics of walking in Australopithecus sediba. Science. Vol. 340, April 12, 2013, p. 1232999-1. doi: 10.1126/science1232999. [Go to]
J. Irish et al. Dental morphology and the phylogenetic “place” of Australopithecus sediba. Science. Vol. 340, April 12, 2013, p. 1233062-1. doi: 10.1126/science1233062. [Go to]
P. Schmid et al. Mosaic morphology in the thorax of Australopithecus sediba. Science. Vol. 340, April 12, 2013, p. 1234598-1. doi: 10.1126/science1234598. [Go to]
S. Williams et al. The vertebral column of Australopithecus sediba. Science. Vol. 340, April 12, 2013, p. 1232996-1. doi: 10.1126/science1232996. [Go to]
B. Bower. Possibly pivotal human ancestor debated. Science News. Vol. 179, May 7, 2011, p. 16. Available online: [Go to]