title: Endocranial capacity in an early hominid cranium from Sterkfontein, South Africa.
abstract: Two- and three-dimensional computer imaging shows that endocranial capacity in an approximately 2.8- to 2.6-million-year-old early hominid cranium (Stw 505) from Sterkfontein, South Africa, tentatively assigned to Australopithecus africanus, is approximately 515 cubic centimeters. Although this is the largest endocranial capacity recorded for this species, it is still markedly less than anecdotal reports of endocranial capacity exceeding 600 cubic centimeters. No australopithecine has an endocranial capacity approaching, let alone exceeding, 600 cubic centimeters. Some currently accepted estimates of early hominid endocranial capacity may be inflated, suggesting that the tempo and mode of early hominid brain evolution may need reevaluation.
authors.affiliation: Department of Anatomy and Neurobiology and Department of Anthropology, Washington University School of Medicine, St. Louis, MO 63110, USA. conroyg@thalamus.wustl.edu
authors.forename: G C
authors.initials: GC
authors.lastname: Conroy
authors.forename: G W
authors.initials: GW
authors.lastname: Weber
authors.forename: H
authors.initials: H
authors.lastname: Seidler
authors.forename: P V
authors.initials: PV
authors.lastname: Tobias
authors.forename: A
authors.initials: A
authors.lastname: Kane
authors.forename: B
authors.initials: B
authors.lastname: Brunsden
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001921:Brain / Q000033:anatomy & histology*; D003198:Computer Simulation; D005580:Fossils; D049690:History, Ancient; D015186:Hominidae / Q000033:anatomy & histology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008953:Models, Anatomic; D012886:Skull / Q000033:anatomy & histology*; D013019:South Africa; D014057:Tomography, X-Ray Computed