Jemdet Nasr
Writing appeared very early in the Middle Uruk period, and then developed further in the Late Uruk and Jemdet Nasr periods. The first clay tablets inscribed with a reed stylus are found in Uruk IV (nearly 2000 tablets were found in the Eanna quarter) and some are found also in Susa II, consisting solely of numeric signs. For the Jemdet Nasr period, there is more evidence from more sites: the majority come from Uruk III (around 3000 tablets), but also Jemdet Nasr, Tell Uqair, Umma, Khafadje, Tell Asmar, Nineveh, Tell Brak, Habuba Kabira, etc. as well as tablets with proto-Elamite writing in Iran (especially Susa), the second writing system to be developed in the Near East.