Reader found, "inter alia", that the flow of rainwater causing the weathering had been stemmed by the construction of 'Khufu's quarries', which lie directly "upstream" of the Sphinx enclosure, and therefore concludes that the Sphinx must predate the reign of Khufu (2589 – 2566 BC), and certainly Khafra, by several hundred years. Reader disagrees with Schoch's palaeometeorological estimates, and instead concludes that the Sphinx dates to the Early Dynastic Period (c. 3150 – 2686 BC). To explain the disproportionate size of the head compared to the body, Reader, as does Schoch, also suggests the head of the Sphinx was originally that of a lion and recarved sometime later in the likeness of a pharaoh. Zahi Hawass, former Egyptian minister of state for antiquities affairs and secretary-general of the Supreme Council of Antiquities, was asked in an interview on the PBS series NOVA if it was possible that a more ancient civilization might have sculpted the Sphinx. Hawass replied: "Of course it is not possible for one reason …. No single artifact, no single inscription, or pottery, or anything has been found until now, in any place to predate the Egyptian civilization more than 5,000 years ago." This reasoning and conclusion was supported in a similar NOVA interview by Mark Lehner, another senior Egyptologist. Other archaeologists who have made similar criticisms include Kenneth Feder. A different argument used by Egyptologists to ascribe the Sphinx to Khafra is the "context" theory, which notes that the Sphinx is located in the context of the funerary complex surrounding the Second Pyramid, which is traditionally connected with Khafra. Apart from the Causeway, the Pyramid and the Sphinx, the complex also includes the Sphinx Temple and the Valley Temple, both of which display the same architectural style, with 100-tonne stone blocks quarried out of the Sphinx enclosure. A diorite statue of Khafra, which was discovered buried upside down along with other debris in the Valley Temple, is claimed as support for the Khafra theory. Reader agrees that the Sphinx Temple and Valley Temple are closely associated with the Sphinx, as is the Causeway and even part of the Khafra Mortuary Temple, but suggests this evidence merely indicates these structures also predate Khafra and does not link the Sphinx in any way to Khafra.