Human teeth from securely stratified Middle Stone Age contexts at Sibudu, South Africa

摘要

The fossil record of early Homo sapiens in the African Pleistocene remains sparse. In contrast to its prominent position regarding the cultural evolution of our species, southern Africa plays a secondary role in narratives regarding human biological origins. Reasons for this are a limited and fragmentary fossil record from the Middle Stone Age (MSA), further complicated by a number of human remains coming from contexts lacking chronostratigraphic information. Similar to the southern African MSA overall, the rich archeological deposits of Sibudu stand in opposition to its scarce record of hominin fossils. Here, we report on three human teeth (SIB-1, 2, 3) from securely stratified MSA deposits at Sibudu dating between >77 and 64ka. The teeth include two lower deciduous molars (Ldm(2)) with heavy occlusal wear and one fragment. We focus on describing the find and archeological context, followed by an initial assessment of the fossils and their contextualization within the African record. The juvenile teeth derive from rich and well-stratified archeological deposits, associated with a Howiesons Poort industry at similar to 64ka from PGS3 (SIB-3) and pre-Still Bay occupations in strata Casper and Danny at >77ka (SIB-1, 2). The latter constitute the oldest human fossils from Sibudu. Metric and morphological analyses of the Ldm(2)s (SIB-2, 3) find a combination of archaic traits (e.g., mid-trigonid crest) and crown dimensions that overlap with ranges of both Pleistocene and recent Homo sapiens. These results match with a population of Homo sapiens that lies chronologically between the earliest members of the species and recent humans.