Pre-Incas kept detailed records too Jude Webber Wednesday, 20 July 2005 This inhabitant of the ancient Peruvian city of Caral would have used knotted string to communicate sophisticated concepts as long as 5000 years ago (Image: Reuters/ Pilar Olivares) A sophisticated arrangement of knots and strings, found on the site of the oldest city in the Americas, indicates ancient Peruvians were skilled at conveying detailed information much earlier than once thought. Archaeologists say the string arrangement, known as a quipu or khipu, indicates ancient Americans were expert communicators thousands of years earlier. Until now the oldest known quipus, often associated...