The cuneiform script was developed from pictographic proto-writing in the late 4th millennium BC, stemming from the near eastern token system used for accounting. These tokens were in use from the 9th millennium BC and remained in occasional use even late in the 2nd millennium BC. Early tokens with pictographic shapes of animals, associated with numbers, were discovered in Tell Brak, and date to the mid-4th millennium BC. It has been suggested that the token shapes were the original basis for some of the Sumerian pictographs.