Notable: Fat residues on elephant-butchering tools

Notable paper: Solodenko N, Zupancich A, Cesaro SN, Marder O, Lemorini C, et al. (2015) Fat Residue and Use-Wear Found on Acheulian Biface and Scraper Associated with Butchered Elephant Remains at the Site of Revadim, Israel. PLoS ONE 10(3): e0118572. doi:10.1371/journal.pone.0118572

Synopsis: Natalya Solodenko and colleagues examined a set of stone tools from a Late Acheulean context, where the tools were found in association with elephant bones bearing cutmarks. They looked at the microscopic wear on the cutting surfaces of the tools to assess how they had been used, finding that a biface was probably used for scraping hides and a scraper was used for processing flesh or hides and also for wood. They also examined the tools using a Fourier Transform Infrared reflectance methodology, finding evidence for both bone residue (likely from bone particles in the deposit rather than use of the tools) and adipocere, a residue of ancient fat from the use of the tools on animal flesh.

Interesting because: As the authors note, there have been few previous instances where both usewear and residue analysis have been applied to tools from the Lower Paleolithic. Yet it seems a promising area:

Herrygers (2002) was able to detect wood residue on Oldowan tools from Koobi Fora, this results support the conclusion drawn from use-wear analysis carried out by Keeley and Toth (1981) [57, 68]. Another example is given by Dominguez-Rodrigo et al (2001) who identified phytoliths on several handaxes from the Acheulian site of Peninj [35]. Hardy and Moncel (2011) identified several plant and animal residues on stone tools related to the Neanderthal Middle Palaeolithic occupation excavated at the site of Payre (France) [56]. Only few works (e.g. [58, 60, 61, 69, 70]) included a combination of both use-wear and residues analyses.

Where is this going? We’re not so long past the days when archaeological projects routinely washed every artifact, eliminating most chances of finding small traces of organic material that might adhere to their surfaces from use. We shouldn’t get carried away with the idea of forensic examination of every flake, as this is incredibly work-intensive and would in many cases impede the recovery of other information from a site. But excavation strategies should include a clear strategy for sampling usewear and residues on artifacts. The field really needs a more coherent infrastructure for carrying out such analyses integrated with the traditional processes of excavation and lithic analysis. This would ideally include blinded study and replication across multiple labs, to regularize the interpretation of both non-destructive methods like FTIR and destructive sampling of residues and sediments.

Science word of the day: Adipocere, often known as “corpse wax”, is a chemical outcome of decay of fat into a soaplike substance.