| Abstract: | The presence of the flyThoracochaeta zosteraein cesspits had led to the unlikely interpretation that seaweed had been present in Mediaeval cesspitis. Archaeological and modern pupae fromT. zosteraewere sampled along with their probable larval diets (extracted plant material from cesspit and seaweed, respectively). The spacing between pupae and food for δ13C and δ15N was similar for both modern and archaeological samples. Modern pupae had isotopic ratios typical for marine invertebrates for δ13C. Archaeological puparia had isotopic values typical for terrestrial grazers (i.e., non-marine), indicating that there was no marine inclusion in the cesspits. |
