Table 1.
δ13C values in bison bone from archaeological sites and resulting estimates of %C4 plants in past plant communities (see text)
| Site | n | MNI | Species | 14C yr BP | yr BP | δ13C | %C4 |
|---|---|---|---|---|---|---|---|
| CKM | 7 | 4 | Bison antiquus | 10,612 (74) | 12,590 (100) | −18.18 (0.88) | 19.72 (6.07) |
| ABF | 11 | 9 | B. antiquus | 10,612 (74) | 12,590 (100) | −17.72 (1.02) | 22.62 (7.03) |
| ABAB | 14 | 14 | B. antiquus | 10,430 (570) | 12,390 (960) | −18.53 (0.56) | 17.03 (3.86) |
| ABHG | 11 | 11 | B. antiquus | 10,157 (325) | 11,910 (706) | −16.62 (1.66) | 30.21 (11.45) |
| HK | 12 | 12 | Bison occidentalis | 6370 (150) | 7280 (147) | −15.49 (2.25) | 38.00 (15.52) |
We calculated the minimum number of individual bison (MNI) sampled from each cultural component by sampling the right calcanei, non-conjoining astragali, or fused 2/3 tarsals (88% of samples), and by significant size or morphological contrasts in bones. Standard deviations are shown in parentheses. For ABF and ABHG, radiocarbon dates were derived from combined regional radiocarbon dates weighed by their standard deviations (11). The ABAB 14C date (RL-557) was the most reliable of four radiocarbon dates. The HK 14C date is the average of two optimal dates (RL-437, RL-185). Radiocarbon dates are converted to calendar years (15).