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Contributed by Ralph L. Holloway, April 5, 2018 (sent for review December 1, 2017; reviewed by James K. Rilling and Chet C. Sherwood)
Significance
The new species Homo naledi was discovered in 2013 in a remote cave chamber of the Rising Star cave system, South Africa. This species survived until between 226,000 and 335,000 y ago, placing it in continental Africa at the same time as the early ancestors of modern humans were arising. Yet, H. naledi was strikingly primitive in many aspects of its anatomy, including the small size of its brain. Here, we have provided a description of endocast anatomy of this primitive species. Despite its small brain size, H. naledi shared some aspects of human brain organization, suggesting that innovations in brain structure were ancestral within the genus Homo.
Abstract
Hominin cranial remains from the Dinaledi Chamber, South Africa, represent multiple individuals of the species Homo naledi. This species exhibits a small endocranial volume comparable to Australopithecus, combined with several aspects of external cranial anatomy similar to larger-brained species of Homo such as Homo habilis and Homo erectus. Here, we describe the endocast anatomy of this recently discovered species. Despite the small size of the H. naledi endocasts, they share several aspects of structure in common with other species of Homo, not found in other hominins or great apes, notably in the organization of the inferior frontal and lateral orbital gyri. The presence of such structural innovations in a small-brained hominin may have relevance to behavioral evolution within the genus Homo.
Footnotes
↵1R.L.H. and S.D.H. contributed equally to this work.
- ↵2To whom correspondence may be addressed. Email: Rlh2{at}columbia.edu or jhawks{at}wisc.edu.
Author contributions: R.L.H., S.D.H., H.M.G., P.T.S., W.B.V., L.R.B., and J.H. designed research, performed research, analyzed data, and wrote the paper.
Reviewers: J.K.R., Emory University; and C.C.S., George Washington University.
Conflict of interest statement: R.L.H. and C.C.S. are coauthors on a 2018 paper published in PNAS.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1720842115/-/DCSupplemental.
- Copyright © 2018 the Author(s). Published by PNAS.
This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND).
Endocast morphology of Homo naledi from the Dinaledi Chamber, South Africa
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- Biological Sciences
- Anthropology
- Social Sciences
- Anthropology
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