Early to mid-Holocene South African Later Stone Age human crania exhibit a distinctly Khoesan morphological pattern

Introduction Khoesan is a term used to identify a large cluster of southern African peoples who share a number of linguistic, cultural and biological traits which distinguish them from neighbouring Bantu-speakers. Although linguistically diverse, all Khoesan groups speak click languages. Similarities in territorial organization, gender relations, kinship, ritual and cosmology are also shared across all Khoesan groups. Biologically, the Khoesan exhibit a number of morphological characteristics such as light yellow-brown skin, epicanthic eyefolds and female steatopygia, that are unique among southern African populations. The Khoesan possess some of the deepest genetic roots of all recent humans, possibly reaching as far back as the early Late Pleistocene. In contrast, their distinctive phenotype appears to have had a much more recent origin. Late Pleistocene South African fossils, such as the c. 110 000–90 000-year-old Klasies River specimens and the c. 80 000–55 000-year-old Border Cave specimens, cannot be securely assigned to any contemporary African population, let alone to the Khoesan, on the basis of craniofacial traits. The more recent Hofmeyr cranium (ELM 24; c. 36 000 years old) also does not resemble the craniofacial pattern of recent Khoesan peoples. On current evidence, the earliest appearance of Khoesan-like craniofacial traits in South African human populations likely dates back to the terminal Pleistocene or early Holocene. Analyses of the ‘Fish Hoek Man’ cranium (SAM-AP 4692), reportedly dated to c. 12 000 BP, indicate a close resemblance to recent Khoesan peoples. However, a secure date for SAM-AP 4692 is not yet available, and therefore this specimen cannot at this stage provide firm support for a terminal Pleistocene age for the appearance of characteristic Khoesan craniofacial traits. The earliest securely dated cranium which displays close morphological affinities to Khoesan crania is the terminal Pleistocene/early Holocene ‘Albany Man’ cranium (UCT 378) from Elands Bay Cave on the Cape southwest coast (Table 1). In addition to UCT 378, systematic excavations in 1978 produced a second fragmentary, early Holocene cranium, UCT 374 (Table 1). Bräuer and Rösing note that UCT 378 combines large overall size and robusticity with typical Khoesan facial morphology. UCT 374 has thus far not been described in the literature. The site of Matjes River Rock Shelter in the southern Cape has also produced several fragmentary human crania from its terminal Pleistocene/early Holocene Layer D. Unfortunately, only one individual from this layer, NMB 1342 (also designated MR 1), has been securely dated to the terminal Pleistocene/early Holocene (Table 1). Like UCT 378, NMB 1342 is a large, robust cranium which displays characteristic Khoesan facial The sample of South African early to mid-Holocene Later Stone Age(LSA) human crania is small and quite fragmentary, limiting our knowledge of human craniofacial morphology for this period. Previous limited analyses have described the morphology displayed by these early crania as a combination of Khoesan and non-Khoesan traits. Although essentially Khoesan-like in terms of facial morphology, their overall large size and robust neurocranial structure were regarded as atypical of Khoesan craniofacial morphology, leading to questions about the role of these early populations in the ancestry of recent Khoesan populations. Here we provide a quantitative analysis in which we compare five well-preserved pre-5000 BP LSA crania with (i) a large sample of post-5000 BP LSA Khoesan crania; and (ii) a sample of crania from recent South African Bantu-speakers. We show that these pre-5000 BP crania fall comfortably within the range of variation observed for the post-5000 BP Khoesan sample, in terms of both size and shape, suggesting that distinctive Khoesan craniofacial morphology was already present in South African LSA populations by the first half of the Holocene.