With some regular intervals we have a look at the Late quartenary megafauna extinction. Currently the American Mastodon (Mammut americanum) has captured our attention. When diving in the literature we observe many dating "problems" like this for instance: http://www.calvin.edu/academic/geology/mastodon/poster/proto4.htm or this real gem: https://kb.osu.edu/dspace/bitstream/1811/5422/1/V68N06_257.pdf Well, there were many problems with carbon dating in those days but on the other hand, can you reject dates that do not fit your idea / hypothesis / theory? In that timeframe, Martin really had forced his will upon the community, the megafauna was over-killed when the first humans allegedly arrived in North America somewhere between 12-10ky crossing the Beringia land bridge. No doubt about that (Not!). So what is your choice when you find datings of 8000 years or 6000 years or 3400 years? It does not fit the theory so it must be contaminated. An excellent example of circular reasoning, the first half that is. Nowadays, we know that extinction took place at a much greater intervals. The horses and woolly rhinos disappeared shortly after the onset of the Bolling event some 14,000 Calendar BP, the last woolly mammoths on Wrangel island at 4150 years Cal BP (3700 14C years). The Irish Elk was also one of the last to go around 6000 years ago. So, why not the American Mastodon? After all, the animal was a browser, specializing on consuming trees, which were abundantly available in the early wet phase of the Holocene, the Preboreal. So, if he survived the Younger Dryas there was no more reason to get extinct in the Preboreal when his biotope restored nicely. Worth ducking into. So we need all the datings of the mastodon and for comparison his buddy, the woolly mammoth (Mammuthus primigenius) who lived in a completely different biotope (steppe) though.