While I agree that Sculpting the Sphinx didn't require drawing on overly sophisticated technology, there are aspects of civilisation to be considered.
Obviously the people involved in the project had to be fed housed and compensated. This in itself is indication of a society that has, at the very least, achieved some degree of organisation and resource sharing.
But where I really beg to differ is..."It is a very simple thing to do, i.e. chip away at stone"
Please! if you think that achieving balance in three dimensional work(ie you can't put any stone back) is easy you have another thing coming.
As a Proffessional Totem Pole Carver, trained in the techniques of the Haida, Kwakuitl, and Tlingit of the North West Coast of NA, I can opine that you believe that it is easy.
Would it be unproffessional for me to ask that, to some degree, you take my word for it that maintaining balance and proportion in a sculpture of the scale of the Sphinx is indicative of a tradition of art that could only be the result of some degree of sophistication in the society that produced the artists.
Let's not forget the tools required.
Can we agree that the Sphinx was made using copper tools?
Where did the copper come from?
How was it smelted?
I could go on but I think my point has been lodged sufficiently.
Please note that I have in no way made any statement regarding when I think the Sphinx was carved, only that, IMHO it was a lot closer to 2500 BC than 10,500 BC. . . based on my opinion as a Sculptor.
Warwick L Nixon