That's interesting - I didn't know that Hancock and Bauval had withdrawn their 10,500BC dating of the Sphinx (though I'm a little suspicious of a carbon date based on the mortar used in the Sphinx as both fresh mortar and new stone cladding could have been introduced at any time during its long history).

Perhaps more interesting are the connections we do seem to have between the Silbury complex and Egypt. One, the word Kennet (or more accurately the sound cunnit) appears to be common to both cultures and carries with it the same notion of fertilty. Two, Silbury and the Zoser (Zil?) Pyramid at Saqqara date from approximately the same time and are remarkably similar in shape. Four, it's got to be more than just coincidence that Silbury, the Zoser Pyramid and the Marlborough Mound are all five-stepped and flat-topped.