Distinguishing wild ruminant lipids by gas chromatography/combustion/isotope ratio mass spectrometry

RATIONALE The carbon isotopic characterisation of ruminant lipids associated with ceramic vessels has been crucial for elucidating the origins and changing nature of pastoral economies. d13C values of fatty acids extracted from potsherds are commonly compared with those from the dairy and carcass fats of modern domesticated animals to determine vessel use. However, the processing of wild ruminant products in pottery, such as deer, is rarely considered despite the presence of several different species on many prehistoric sites. To address this issue, the carbon isotope range of fatty acids from a number of red deer (Cervus elaphus) tissues, a species commonly encountered in the European archaeological record, was investigated. METHODS Lipids were extracted from 10 modern red deer tissues obtained from the Slowinski National Park (Poland). Fatty acids were fractionated, methylated and analysed by gas chromatography/combustion/isotope ratio mass spectrometry (GCCIRMS). The d13C values of n-octadecanoic acid and n-hexadecanoic acid, and the difference between these values (?13C), were compared with those from previously published ruminant fats. RESULTS Nine of the ten deer carcass fats measured have ?13C values of less than -3.3 parts per thousand, the threshold previously used for classifying dairy products. Despite considerable overlap, dairy fats from domesticated ruminants with ?13C values less than -4.3 parts per thousand are still distinguishable. CONCLUSIONS The finding has implications for evaluating pottery use and early pastoralism. The processing of deer tissues and our revised criteria should be considered, especially where there is other archaeological evidence for their consumption. Copyright (c) 2012 John Wiley & Sons, Ltd.