Heritage Cases

Introduction This proposal is for a feasibility study to assess if the amount of collagen present in micromammal bone material from Middle Stone Age (MSA) levels at Klipdrift Shelter (KDS) (Henshilwood et al. 2014), De Hoop Nature Reserve, are suitable for genus/species identification using Zooarchaeology by Mass Spectrometry (ZooMS) (Buckley et al. 2009, 2016, 2018). The feasibility study will use identified micromammal species by dental morphology and non-identifiable cranial and post-cranial elements/fragments from section and surface cleanings of the MSA deposits at KDS. The reference database of modern taxa have been collected from barn owl pellets at roost sites in De Hoop Nature Reserve. Our goal is to determine the potential of ZooMS as a method of identifying micromammal species from archaeological sites and thus develop a methodology for future analyses while initiating a reference database of extant micromammal species from the southern coastal region in South Africa. The ZooMS analyses will be undertaken at the Max Planck Institute for the Science of Human History (MPI-SHH) in Jena, Germany, under the guidance of Dr. Katerina Douka and Dr. Patrick Roberts. The analyses will commence in April 2019 and the material will be returned to South Africa by April 2020, as per agreement with Iziko South African Museum, Cape Town (see attachment). In terms of the National Heritage Resources Act (Act 25 of 1999), section 35(4), a temporary export permit must be obtained prior to analysis. Aims Our initial aim is to determine if there are sufficient amounts of collagen present in micromammal bone from MSA deposits for ZooMS analyses. Secondly we would like to identify the taxonomic level at which species identification can be made. If the feasibility study is successful, our ultimate aim is to supplement morphological identification with ZooMS analyses of micromammal material from the Howiesons Poort sequences at KDS and Klasies River main site. Concurrently we will collect extant micromammal species from the Western and Eastern Cape and set up a reference database for identification by ZooMS. Rationale Due to the fragmentary nature of micromammal material recovered from archaeological sites, morphological identification of micromammals may be complicated and time consuming. Taxonomic identification is done by dental morphology, but a significant amount of potential identification of taxa is hampered due to breakage, digestion, post-depositional processes and thus missing taxonomic identifiable characteristics. Additionally, many birds of prey, which are the usual accumulators of micromammal archaeological assemblages, remove the heads from their rodent prey prior to consuming the remainder of the carcass (e.g. Glue 1967). Identification of species based on post-cranial rodent remains is not methodologically developed nor viable due to frequent fragmentation and lacking research on taxonomic morphological traits. ZooMS, where collagen acts as a barcode with a specific identification for each genus/species, allows for identification of non-morphological bone and have the potential to supplement and refine the current methodology in the field of micromammal analyses (Van der Sluis et al. 2014; Buckley et al. 2016, 2018). The method has been tested on large mammal assemblages from archaeological sites (Buckley et al. 2009), but remains relatively unexplored on micromammal samples. Buckley et al. (2018) have recently applied ZooMS on arvicoline rodents (voles and lemmings), the dominant mammalian taxonomic group present at the Late Pleistocene site of Pin Hole Cave, Creswell Crags U.K., and were able to demonstrate that some taxa can be objectively distinguished to genus and in some cases species. ZooMS has the potential to increase the number of identified species and/or improve assessment of proportional abundance of species in an assemblage, especially when supplemented to morphological identification (Buckley et al. 2018). Applying ZooMS to archaeological samples requires setting up a modern reference database of identified extant species, and our feasibility study will initiate this work. This database will also benefit future micromammal ZooMS analyses in the region. If successful, ZooMS has the potential to increase the sample size of archaeological material for analysis, reduce time required for traditional morphometrics identification and offer a cost-efficient solution compared to aDNA analyses. The “Zooarchaeology by Mass Spectrometry” Laboratory at MPI-SHH, Department of Archaeology, Jena, Germany, have been selected as facilitators as they are one of the leading laboratories for ZooMS analyses. Presently there is no equivalent expertise of this methodology in South Africa. This type of analyses requires a Matrix assisted laser desorption/ionisation time of flight mass spectrometer (MALDI-Tof-MS) is a specialized instrument (~€0.5M) exclusively used on archaeological material at the MPI-SHH. Following the pilot study we propose to undertake here, and with expertise and interest building in the country, it may become possible that the first part of the pretreatment (collagen extraction and purification) will take place in South Africa, so that all bone materials stay in the country and only extracted collagen is exported.