Tigris–Euphrates river system through the central plain and combine at Al-Qurnah to form the Shatt al-Arab and discharge into the Persian Gulf. The region has historical importance as part of the Fertile Crescent region, in which civilization is believed to have first emerged. The ecoregion is characterized by two large rivers, the Tigris and Euphrates. The rivers have several small tributaries which feed into the system from shallow freshwater lakes, swamps, and marshes, all surrounded by desert. The hydrology of these vast marshes is extremely important to the ecology of the entire upper Persian Gulf. Historically, the area is known as Mesopotamia. As
Euphrates softshell turtle sandy banks and many fish (especially cyprinids). Although it mainly resides in shallow calm water, this is typically adjacent to deep fast-flowing water. In the fast-flowing Euphrates it generally avoids the main stem, instead occurring in side-branches or backwaters. In parts of the Tigris River with a slower flow, it occurs even in the main stem. They bask on or at the banks of rivers, with some remaining in shallow water to avoid being on land. They sometimes bury themselves into the bottom. The Euphrates softshell turtle is mainly active during the day, but some night-activity also occurs. In parts