Abstract
Steroids are used as faecal markers in environmental and in archaeological studies, because they provide insights into ancient agricultural practices and the former presence of animals. Up to now, steroid analyses could only identify and distinguish between herbivore, pig, and human faecal matter and their residues in soils and sediments. We hypothesized that a finer differentiation between faeces of different livestock animals could be achieved when the analyses of several steroids is combined (Δ5-sterols, 5α-stanols, 5β-stanols, epi-5β-stanols, stanones, and bile acids). We therefore reviewed the existing literature on various faecal steroids from livestock and humans and analysed faeces from old livestock breed (cattle, horse, donkey, sheep, goat, goose, and pig) and humans. Additionally, we performed steroid analyses on soil material of four different archaeological periods (sites located in the Lower Rhine Basin, Western Germany, dating to the Linearbandkeramik, Urnfield Period / Bronze Age, Iron Age, Roman Age) with known or supposed faecal inputs. By means of already established and newly applied steroid ratios of the analysed faeces together with results from the literature, all considered livestock faeces, except sheep and cattle, could be distinguished on the basis of their steroid signatures. Most remarkably was the identification of horse faeces (via the ratio: epi-5β-stigmastanol: 5β-stigmastanol + epicoprostanol: coprostanol; together with the presence of chenodeoxycholic acid) and a successful differentiation between goat (with chenodeoxycholic acid) and sheep/cattle faeces (without chenodeoxycholic acid). The steroid analysis of archaeological soil material confirmed the supposed faecal inputs, even if these inputs had occurred several thousand years ago.
Highlights
Archaeological excavations frequently discover organic-rich topsoil material potentially influenced by human or animal remains, but not necessarily mixed with archaeological artefacts.PLOS ONE | DOI:10.1371/journal.pone.0164882 January 6, 2017Steroid Biomarkers - Improved Identification of Faecal Remains in Archaeological Soil Material
We combined for the first time the assessment of Δ5-sterols, 5α-stanols, 5β-stanols, epi-5β-stanols, stanones, and bile acids for a differentiation between different livestock faeces, including faeces from different herbivore livestock, and we complemented our data set by a compilation of literature data
Both the bile acid methyl ester and the Δ5-sterol, stanol, and stanone fraction were spiked with 5α-cholestane before analysis by gas chromatography-mass spectrometry (GC/MS) with an Agilent 5973 quadrupole mass spectrometer coupled to an Agilent 6890 gas chromatograph (Agilent, Boblingen, Germany)
Summary
Archaeological excavations frequently discover organic-rich topsoil material potentially influenced by human or animal remains, but not necessarily mixed with archaeological artefacts. To account for the potential of using the steroid composition for source assignment, several steroid ratios for detection of faecal input into soils and sediments have been proposed to date These ratios usually use 5β-stanols as well as their transformation products (Fig 1). The main objective of this work, was, to improve source identification for common livestock faeces by their steroid composition (considering the impact of diet and breed) and to elucidate if the identified steroid compositions can be detected in respective archaeological soil material To achieve this aim, we combined for the first time the assessment of Δ5-sterols, 5α-stanols, 5β-stanols, epi-5β-stanols, stanones, and bile acids for a differentiation between different livestock faeces, including faeces from different herbivore livestock, and we complemented our data set by a compilation of literature data. We did not consider faeces from livestock that were fed with silage or concentrate to ensure comparability of results from steroid analysis in faeces and in archaeological soil material and chose archaeological soil samples with strong indications on ancient livestock management or a human faecal input
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
