A team of archaeologists has discovered what it says is evidence of humankind's oldest ritual. Africa's San people may have used a remote cave for ceremonies of python worship as much as 70,000 years ago, that is, 30,000 years earlier than the oldest previously known human rites, the team says. The researchers found a large rock inside the cave that they say resembles a giant python, with natural features in the stone forming an eye and a mouth. The 20-foot-by-6.5-foot (six metre by two metre) stone was also scarred by several hundred human-made grooves that may have been meant to resemble scales. Beneath the python rock, scientists found a section of curved wall, which they believe may have collapsed during work on the "python". The researchers also discovered quartz flakes packed in some of the cave's crevices. And the team unearthed spearheads identical to those found at another site in Botswana, which had been dated to 77,000 years ago.