[From the Christian Science Monitor] (Not rock pile related, this goes more to the pigheaded-ness of archeologists.)
This is an elegant study of mastadon populations. Apparently a fungus which grows only in mastadon dung has population cycles that match the mastadon population cycles. So, this fungus makes spores that can be counted and compared layer-to-layer in lake bottom sediments; and this documents the increases and decreases of mastadon populations in the past.
As was know, but this substantiates it, mastadon s were already in decline 1,500 years before the so called "Clovis Culture" - the paleo-Indians described as the "great game hunters"...you know the intrepid hunter gatherers who followed the mastadon across the Bering land bridge. Now since we have clearer evidence of this premature mastadon decline, the conclusion from archeologists is that something other than over-hunting must have caused the population declines.
This conclusion is coming from the people who have a hard time acknowledging that man was already here before Clovis. There are only a few people left who still think "Clovis was first". Hopefully they are going the way of the mastadon (or more aptly, the way of that dung fungus). But let me get this argument straight: mastadons dying out before Clovis shows that mastadons were not hunted to extinction because pre-Clovis people did not hunt mastadons. Seems a bit circular.
Don't get me wrong, there is good evidence that other factors caused the decline. In particular but rarely mentioned: there were a large number of non-game species that died out in the same 30K-10Y years ago time interval. For example certain species of mouse and of owl. Hard to imagine all these things depending on a eco-system with mastadons.