The methodology for calculating the number of Euryale ferox and Trapa natans nuts in the archaeological record at GBY was as follows:
E. ferox – calculation of nut numbers: The number of complete nuts (Table 1) was calculated for each excavated unit by estimating the number of fragments that could be conjoined to form a single nut coat. When this estimate suggested the presence of more than one nut, the number was rounded up to two, and so forth. However, some units yielded fragments including characteristic structures such as the attachment scar (hilum) or germination aperture of the nuts. In such cases, their number was compared to the estimated value derived from the conjoined fragments and the higher value was considered to represent the minimum number of complete nuts in the assemblage.
T. natans – calculation of nut numbers: The nuts of T. natans (Table 1) consist of a single nut enclosed within a bony calyx. The calyx bears four lateral spines, a typical depression at the base and an aperture surrounded by an extended rim at the tip. Most of the T. natans remains from GBY are fragments of the nut wall, while others are spines, apertures or bases. Hence, the number of nuts in each layer/level was calculated by estimating the number of fragments that could be conjoined to form a single nut wall. In addition, for layers/levels that also contained spines, apertures and bases, each structure was counted separately and the number of spines was divided by four. In such cases, as for E. ferox, their number was compared to the estimated value derived from the conjoined fragments and the higher value was considered to represent the minimum number of complete nuts in the assemblage.