What is the old Sphinx theory?

Attracted little interest until 1990 when Robert Schoch,a trained geologist and Boston University professor,found rock fissures in the Sphinx that suggested creation by running water or rainfall.He concluded that the front and side dated from 5000 to 7000 B.C. (although no one disputes that it was later recarved as a royal totem).But if Schoch is right,a cruder yet still impressive "proto-Sphinx" was carved in the even more distant past.