Within the genus Homo, cranial capacity again doubled from H. habilis through Homo ergaster or H. erectus to Homo heidelbergensis by 0.6 million years ago. The cranial capacity of H. heidelbergensis overlaps with the range found in modern humans.
The original height of the Pyramid was 146.5 m (488 ft), but today it is only 137 m (455 ft) high, the 9 m (33 ft) that is missing is due to the theft of the fine quality white Tura limestone covering, or casing stones, for construction in Cairo. It is still the tallest pyramid.
As of November 2008, sources cite either 118 or 138 as the number of identified Egyptian pyramids. Most were built as tombs for the country's pharaohs and their consorts during the Old and Middle Kingdom periods. The earliest known Egyptian pyramids are found at Saqqara, northwest of Memphis. The earliest among these is the Pyramid of Djoser (constructed 2630 BCâ2611 BC) which was built during the third dynasty.