Non-destructive ZooMS identification reveals strategic bone tool raw material selection by Neandertals

Abstract

Five nearly identical fragments of specialized bone tools, interpreted as lissoirs (French for "smoothers"), have been found at two Middle Paleolithic sites in southwest France. The finds span three separate archaeological deposits, suggesting continuity in the behavior of late Neandertals. Using standard morphological assessments, we determined that the lissoirs were produced on ribs of medium-sized ungulates. However, since these bones are highly fragmented and anthropogenically modified, species determinations were challenging. Also, conservative curation policy recommends minimizing destructive sampling of rare, fragile, or small artifacts for molecular identification methods. To better understand raw material selection for these five lissoirs, we reassess their taxonomy using a non-destructive ZooMS methodology based on triboelectric capture of collagen. We sampled four storage containers and obtained identifiable MALDI-TOF MS collagen fingerprints, all indicative of the same taxonomic clade, which includes aurochs and bison (Bos sp. and Bison sp.). The fifth specimen, which was stored in a plastic bag, provided no useful MALDI-TOF MS spectra. We show that the choice of large bovid ribs in an archaeological layer dominated by reindeer (Rangifer tarandus) demonstrates strategic selection by these Neandertals. Furthermore, our results highlight the value of a promising technique for the non-destructive analysis of bone artifacts.

Figure 1

Photographs of the (a) Pech-de-l’Azé I (PA I) and (b-e) Abri Peyrony (AP) lissoirs. (a) PA I G8-1417. (b) AP-4209. (c) AP-4493. (d) AP-10818, newly published here. (e) AP-7839. Adapted/modified from.

Figure 2

Examples of non-destructive MALDI-TOF MS spectra. (a) Membrane extraction blank. (b) Washing control #2 from Les Cottés. This spectrum represents one example of eight washing and sedimentary control samples processed. (c) Lissoir (AP-4209) from Abri Peyrony. The top row displays the complete spectrum in the m/z range 1000 – 3500. The bottom row displays a close-up view of the m/z range around peptide marker P1 (1105 m/z) and A (1208 m/z for Bos sp./Bison sp.). Note the difference in peptide intensity between the controls and the lissoir.

Figure 3

Ungulate species composition by the number of identified specimens (NISP) of the layers that preserved the lissoirs at Pech I and Abri Peyrony (AP); lissoirs indicated by their taxonomic identity as observed through ZooMS. Specimens not identified to species, such as medium and large ungulates (ung), are depicted with diagonal stripes between their most likely attributed species. For simplicity, categories “red deer/reindeer”, “cervid/saiga”, and “medium ungulate” in Tables 1 and 2 are combined into “medium ungulate” here. Lissoir depictions courtesy of Anna E. Goldfield.