Our "ancient" history dribbles out. Personally, I think the author is misdating the age of Sumerian civilization -- clay tablets presenting the "king's list" make it much older that current estimates.

The Dispilio Tablet - the oldest known written text

www.ancient-origins.net

According to conventional archaeology, writing wasn’t invented until 3000 to 4000 BC in Sumeria.  However, an artefact was found over a decade ago which contradicts this belief – and