How old is civilization?
Rain weathering on the base of the sphinx suggests that it is at least 6000 years old. Was there an ancient Masma civilization?
It is highly unlikely that we became hairless in anything less than 10,000 years so it is much more probable that there were many ancient complex civilizations at least 10,000 years ago. The questions is what happened to them? Was there really a flood 6500 years ago that wiped the slate clean?