RT Journal Article SR Electronic T1 Australopithecus afarensis endocasts suggest ape-like brain organization and prolonged brain growth JF Science Advances JO Sci Adv FD American Association for the Advancement of Science SP eaaz4729 DO 10.1126/sciadv.aaz4729 VO 6 IS 14 A1 Gunz, Philipp A1 Neubauer, Simon A1 Falk, Dean A1 Tafforeau, Paul A1 Le Cabec, Adeline A1 Smith, Tanya M. A1 Kimbel, William H. A1 Spoor, Fred A1 Alemseged, Zeresenay YR 2020 UL http://advances.sciencemag.org/content/6/14/eaaz4729.abstract AB Human brains are three times larger, are organized differently, and mature for a longer period of time than those of our closest living relatives, the chimpanzees. Together, these characteristics are important for human cognition and social behavior, but their evolutionary origins remain unclear. To study brain growth and organization in the hominin species Australopithecus afarensis more than 3 million years ago, we scanned eight fossil crania using conventional and synchrotron computed tomography. We inferred key features of brain organization from endocranial imprints and explored the pattern of brain growth by combining new endocranial volume estimates with narrow age at death estimates for two infants. Contrary to previous claims, sulcal imprints reveal an ape-like brain organization and no features derived toward humans. A comparison of infant to adult endocranial volumes indicates protracted brain growth in A. afarensis, likely critical for the evolution of a long period of childhood learning in hominins.