Endocast morphology of Homo naledi from the Dinaledi Chamber, South Africa

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 .