Paibi was selected over the Kyrshabakty River section, Malyi Karatau, Kazakhstan, and the GSSP was ratified by the International Union of Geological Sciences in late 2003.
The GSSP designation for the Paibi site in Kazakhstan was finalized in late 2003 after a selection process that involved comparing it to other potential sites like the Kyrshabakty River section and Malyi Karatau. This decision was made by the International Union of Geological Sciences.