Species identification and decay assessment of Late Pleistocene fragmentary vertebrate remains from Pin Hole Cave (Creswell Crags, UK) using collagen fingerprinting

Ancient bone remains are widely utilized when investigating vertebrate biodiversity of past animal populations but are often so highly fragmented that the majority of specimens cannot be identified to any meaningful taxonomic level. Recently, high-throughput methods for objective species identification using collagen peptide mass fingerprinting have been created to overcome this with the added indication that they could also offer a means of relative ageing through decay measurement. Here we explore both species identification and decay measurements for the Pin Hole Cave microfaunal' assemblage, the site that has been designated as a representative for Marine Oxygen Isotope Stage 3 in Britain in terms of its suite of mammalian fauna. We explore the technique's potential to corroborate the faunal diversity established previously by macroscopic studies and evaluate the decay measurements across the species boundary. The results support that the analysis of fragmentary remains by collagen fingerprinting can yield a more diverse set of fauna, and offer additional information relating to taphonomy, than the analysis of morphologically intact bones on their own. However, although useful for identifying likely contaminations of an assemblage, there was an unexpected decrease in the decay measurements observed for some megafauna compared with much younger microfauna, indicating that other factors need to be carefully monitored before it could be used as a relative ageing technique in Quaternary deposits.