Late Pleistocene age and archaeological context for the hominin calvaria from GvJm-22 (Lukenya Hill, Kenya)

• Published in: Proceedings of the National Academy of Sciences - PNAS 2015-03, Vol.112 (9), p.2682-2687
• Main Authors: Tryon, Christian A., Crevecoeur, Isabelle, Faith, J. Tyler, Ekshtain, Ravid, Nivens, Joelle, Patterson, David, Mbua, Emma N., Spoor, Fred
• Format: Article
• Language: English
• Subjects: Archaeology and Prehistory; Behavior; Biological Sciences; Comparative analysis; Craniology; Fossils; Hominids; Humanities and Social Sciences; Humans; Kenya; Mass Spectrometry; Skull; Social Sciences
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1417909112

Significance Modern human ( Homo sapiens ) fossils from eastern African archaeological contexts from ∼70,000–20,000 years ago are rare, limiting our ability to understand the relationship between biological and behavioral change during a time and place characterized by major human demographic shifts, including dispersals. Our chronological, archaeological, and human paleontological analyses of the GvJm-22 rock shelter and Kenya National Museums Lukenya Hill Hominid 1 partial calvaria constrain the age of major behavioral changes among African foragers (the shift to Later Stone Age technologies) and demonstrate the morphological distinctness of Late Pleistocene African hominins from African Holocene or Late Pleistocene Eurasian hominins, complicating the history of modern human diversity. Kenya National Museums Lukenya Hill Hominid 1 (KNM-LH 1) is a Homo sapiens partial calvaria from site GvJm-22 at Lukenya Hill, Kenya, associated with Later Stone Age (LSA) archaeological deposits. KNM-LH 1 is securely dated to the Late Pleistocene, and samples a time and region important for understanding the origins of modern human diversity. A revised chronology based on 26 accelerator mass spectrometry radiocarbon dates on ostrich eggshells indicates an age range of 23,576–22,887 y B.P. for KNM-LH 1, confirming prior attribution to the Last Glacial Maximum. Additional dates extend the maximum age for archaeological deposits at GvJm-22 to >46,000 y B.P. (>46 kya). These dates are consistent with new analyses identifying both Middle Stone Age and LSA lithic technologies at the site, making GvJm-22 a rare eastern African record of major human behavioral shifts during the Late Pleistocene. Comparative morphometric analyses of the KNM-LH 1 cranium document the temporal and spatial complexity of early modern human morphological variability. Features of cranial shape distinguish KNM-LH 1 and other Middle and Late Pleistocene African fossils from crania of recent Africans and samples from Holocene LSA and European Upper Paleolithic sites.