Peptide mass fingerprinting as a tool to assess micromammal biodiversity in Pleistocene South Africa: The case of Klipdrift Shelter

Remains of small mammals from archaeological sites are often used as palaeoenvironmental proxies in the reconstruction of past environments. Yet, identification of micromammals to species-level based on morphological traits is often difficult due to fragmentation of diagnostic skeletal elements. Here we test the potential of Zooarchaeology by Mass Spectrometry (ZooMS) as a tool for the taxonomic identification of micromammal remains from Middle Stone Age (MSA) sequences in South Africa. ZooMS peptide markers are first established for 14 extant micromammal species present in the region. These novel peptide markers are then used to identify micromammal bone remains from the MSA levels of Klipdrift Shelter (c. 72-51 ka), De Hoop Nature Reserve, South Africa. Our study shows that collagen preservation in micromammal bones from MSA contexts is sufficient for successful ZooMS analysis. To our knowledge, these results represent the oldest material successfully analysed with ZooMS from an African context. The peptide markers developed as part of this study can be used to characterize a larger number of micromammal assemblages. This holds significant promise for the future application of ZooMS to prehistoric material in South Africa and elsewhere in the continent.