Table 1.
Radiocarbon (14C) dates on American mastodon fossils from Alaska and Yukon
| Specimen no. | 14C years B.P. | Lab no. | Details |
| Previously published radiocarbon dates | |||
| Yukon | |||
| CMN 33897 | 24,980 ± 1300 | Beta 16163 | ref. 7 |
| YG 33.2 | >45,130 | Beta 189291 | ref. 27 |
| YG 43.2 | 18,460 ± 350 | TO 7745 | ref. 25 |
| Alaska | |||
| UAMES 2414 | >50,000 | CAMS 91805 | ref. 26 |
| New radiocarbon dates on previously published Yukon specimens | |||
| CMN 33897 | >51,700 | UCIAMS 78694 | UF |
| YG 43.2 | >49,200 | UCIAMS 75320 | UF |
| New specimens with single radiocarbon dates | |||
| Yukon | |||
| CMN 8707 | >51,700 | UCIAMS 78700 | UF |
| CMN 11697 | >51,700 | UCIAMS 78698 | UF |
| CMN 15352 | 45,700 ± 2500 | UCIAMS 78695 | UF |
| CMN 31898 | 50,300 ± 3500 | UCIAMS 78696 | UF |
| CMN 33066 | >49,900 | UCIAMS 78697 | UF |
| CMN 42551 | >51,700 | UCIAMS 78699 | UF |
| CMN 42552 | >41,100 | UCIAMS 78703 | UF |
| F:AM: 104842 | 42,100 ± 1300 | UCIAMS 88773 | UF |
| YG 50.1 | >41,100 | AA 84994 | STD |
| YG 139.5 | >41,100 | AA 84985 | STD |
| YG 357.1 | >41,100 | AA 84995 | STD |
| YG 361.9 | >49,900 | UCIAMS 72419 | UF |
| Alaska | |||
| F:AM: 103281 | >50,800 | UCIAMS 88775 | UF |
| F:AM: 103292 | 46,100 ± 2100 | UCIAMS 88771 | UF |
| F:AM: 103295 | >46,900 | UCIAMS 88774 | UF |
| UAMES 7666 | >50,800 | UCIAMS 88767 | UF |
| UAMES 7667 | 51,300 ± 4000 | UCIAMS 88766 | UF |
| UAMES 30197 | >51,700 | UCIAMS 117242 | UF |
| UAMES 30198 | >51,200 | UCIAMS 117243 | UF |
| UAMES 30199 | >46,400 | UCIAMS 117235 | UF |
| UAMES 30200 | 47,000 ± 2300 | UCIAMS 117241 | UF |
| UAMES 30201 | >47,500 | UCIAMS 117232 | UF |
| UAMES 34126 | >46,100 | UCIAMS 117237 | UF |
| New specimens with multiple radiocarbon dates | |||
| Yukon | |||
| CMN 333 | 40,600 ± 1000 | UCIAMS 78701 | UF |
| >47,800 | UCIAMS 83803 | UF | |
| >49,500 | UCIAMS 83804 | UF | |
| YG 26.1 | 39,200 ± 3200 | AA 84981 | STD |
| >50,300 | UCIAMS 78705 | UF | |
| >51,700 | UCIAMS 78704 | UF | |
| Alaska | |||
| F:AM: 103277 | 29,610 ± 340 | OxA-25402 | UF |
| 33,810 ± 460 | UCIAMS 88772 | UF | |
| 47,100 ± 2500 | OxA-X-2490–48 | SAA | |
| F:AM: 103291 | 35,240 ± 610 | UCIAMS 88776 | UF |
| 42,800 ± 2400 | OxA-X-2515–35 | SAA | |
| 44,900 ± 2600 | OxA-X-2515–34 | SAA | |
| UAMES 2414 | >50,000 | CAMS 91805 | STD |
| >48,100 | UCIAMS 117234 | UF | |
| UAMES 7663 | 20,440 ± 130 | OxA-25401 | UF |
| 33,090 ± 470 | UCIAMS 88768 | UF | |
| 43,000 ± 2200 | OxA-X-2457–7 | SAA | |
| 48,200 ± 2600 | OxA-X-2492–15 | SAA | |
| UAMES 9705 | 38,800 ± 1100 | CAMS 53904 | STD |
| >51,700 | UCIAMS 117239 | UF | |
| UAMES 11095 | >51,200 | UCIAMS 117233 | UF |
| >54,000 | CAMS 91808 | STD | |
| UAMES 12047 | 51,700 ± 3200 | CAMS 92090 | STD |
| >48,800 | UCIAMS 117240 | UF | |
| UAMES 12060 | 36,370 ± 790 | AA-48275 | STD |
| 49,800 ± 3300 | UCIAMS 117236 | UF | |
| UAMES 34125 | 31,780 ± 360 | UCIAMS 117238 | UF |
| >50,100 | OxA-29838 | UF | |
All nominally finite radiocarbon dates are reported to 1σ. Specimen collection repositories: CMN, Canadian Museum of Nature; F:AM, Frick Collection of the American Museum of Natural History; UAMES, University of Alaska Museum Earth Sciences Collection; YG, Yukon Government Paleontology Program. Radiocarbon laboratories: AA, Arizona Accelerator Mass Spectrometry Laboratory; Beta, Beta Analytic Radiocarbon Laboratory; CAMS, Lawrence Livermore National Laboratory Center for Accelerator Mass Spectrometry; OxA, Oxford Radiocarbon Accelerator Unit; TO, Isotrace Laboratory the Canadian Centre for Accelerator Mass Spectrometry; UCIAMS, University of California, Irvine Keck Carbon Cycle Accelerator Mass Spectrometry Laboratory. Fraction dated: SAA, single amino acid hydroxyproline (35); STD, standard collagen gelatin pretreatment without ultrafiltration (49); UF, ultrafiltered collagen (32, 34).