2134/25680
Noel Cameron
Noel
Cameron
Barry Bogin
Barry
Bogin
Debra Bolter
Debra
Bolter
Lee R. Berger
Lee R.
Berger
The postcranial skeletal maturation of Australopithecus sediba
Loughborough University
2017
Evolution of growth
Hominin ontogeny
Maturity indicators
Postcranial skeleton
Evolutionary Biology
Anthropology
Medical and Health Sciences not elsewhere classified
Archaeology
2017-07-03 09:05:53
Journal contribution
https://repository.lboro.ac.uk/articles/journal_contribution/The_postcranial_skeletal_maturation_of_Australopithecus_sediba/9629132
OBJECTIVES: In 2008, an immature hominin defined as the holotype of the new species Australopithecus sediba was discovered at the 1.9 million year old Malapa site in South Africa. The specimen (MH1) includes substantial post-cranial skeletal material, and provides a unique opportunity to assess its skeletal maturation. METHODS: Skeletal maturity indicators observed on the proximal and distal humerus, proximal ulna, distal radius, third metacarpal, ilium and ischium, proximal femur and calcaneus were used to assess the maturity of each bone in comparison to references for modern humans and for wild chimpanzees (Pan troglodytes). RESULTS: In comparison to humans the skeletal maturational ages for Au. sediba correspond to between 12.0 years and 15.0 years with a mean (SD) age of 13.1 (1.1) years. In comparison to the maturational pattern of chimpanzees the Au. sediba indicators suggest a skeletal maturational age of 9-11 years. Based on either of these skeletal maturity estimates and the body length at death of MH1, an adult height of 150-156 cm is predicted. DISCUSSION: We conclude that the skeletal remains of MH1 are consistent with an ape-like pattern of maturity when dental age estimates are also taken into consideration. This maturity schedule in australopiths is consistent with ape-like estimates of age at death for the Nariokotome Homo erectus remains (KMN-WT 15000), which are of similar postcranial immaturity to MH1. The findings suggest that humans may have distinctive and delayed post-cranial schedules from australopiths and H. erectus, implicating a recent evolution of somatic and possibly life history strategies in human evolution.