An excursus is similar to an appendix and provides a digression from the main text. The excursuses are completely optional and are not part of the course. This excursus compares the history of the Late Neolithic Mesopotamia to Moses' description of the period from Adam and Eve to Noah. This period from 5800 BC to 3500 BC begins the appearance the Ubaid in the archaeological record in 5800 BC in southern Mesopotamia, and ends with the Mesopotamian Great Ur Flood in 3500 BC.Â