It's possible that all of those numbers are wrong -- not by a couple thousand years, but by tens of thousand of years. Göbekli Tepe was only recently discovered and dated in Turkey, it pre dates the pyramids by over 11,500 years.
http://www.thedailybeast.com/newsweek/2010/02/18/history-in-the-remaking.html
If you look at the floor of the Med you'll find dozens, if not hundreds of ancient sites that were lost when the coast line rose after the ice age. We are told that the Sumerians were the world's first civilization formed around 4,000 BC -- 1500 years before construction began on the pyramids. Yet Göbekli Tepe predates the formation of Sumeria by almost 10,000 years itself.
What we think we know about our ancient past is ever-changing and constantly being redefined.