A rich civilisation (possibly in the millions), leaving absolutely no trace in any shape or form? Maybe time to apply Occam's Razor. On the other hand, a green

A rich civilisation (possibly in the millions), leaving absolutely no trace in any shape or form? Maybe time to apply Occam's Razor. On the other hand, a green north Africa is well established. And it turns out that the Ancient Egyptians might have descended from hunter-gatherers who were driven towards the nile as the grasslands gave way to desert. For all of which there is archaeological evidence.