I dunno what wiped out the mayan dynastic kultur.  the commons are still there, but perhaps disease and/or climate change made them unable to tolerate a ruling elite.  the same thing happened to the aztecs, invaders whose elite were wiped out by the native mexicans after only a century of misrule.

p.s. it's approx. 60 F here.  doesn't snow much here, excepting the sierra.  if we can't discuss religion nor politics, that leaves the weather as the only topic that keeps the trolls at bay.