苏美尔语
The entire Early Dynastic period is generally dated to 2900–2350 BC according to the Middle Chronology, or 2800–2230 BC according to the Short Chronology. The Sumerians were firmly established in Mesopotamia by the middle of the 4th millennium BC, in the archaeological Uruk period, although scholars dispute when they arrived. It is hard to tell where the Sumerians might have come from because the Sumerian language is a language isolate, unrelated to any other known language. Their mythology includes many references to the area of Mesopotamia but little clue regarding their place of origin, perhaps indicating that they had been there for a long time. The Sumerian language is identifiable from its initially logographic script which arose last half of the 4th millennium BC.