In the Latest Devonian to Mississippian periods, Ural Ocean became a seaway. Until the three collided in the Carboniferous, it created the Ural Mountains, completely closing the ocean, and forming the Pangaea supercontinent.
During the Late Devonian to Mississippian periods, the Ural Ocean transformed into a seaway.  Before colliding in the Carboniferous period, it formed the Ural Mountains, completely sealing the ocean and forming the Pangaea supercontinent.