Abstract: In 1841, Murchison coined the term Permian for strata in the Russian Urals. Recognition of the Permian outside of Russia and central Europe soon followed, but it took about a century for the Permian to be accepted globally as a distinct geological system. The work of the Subcommission on Permian Stratigraphy began in the 1970s and resulted in current recognition of nine Permian stages in three series: the Cisuralian (lower Permian) – Asselian, Sakmarian, Artinskian and Kungurian; the Guadalupian (middle Permian) – Roadian, Wordian and Capitanian; and the Lopingian (upper Permian) – Wuchiapingian and Changhsingian. The 1990s saw the rise of Permian conodont biostratigraphy, so that all Permian Global Stratigraphic Sections and Points (GSSPs) use conodont evolutionary events as the primary signal for correlation. Issues in the development of a Permian chronostratigraphic scale include those of stability and priority of nomenclature and concepts, disagreements over changing taxonomy, ammonoid v. fusulinid v. conodont biostratigraphy, differences in the perceived significance of biotic events for chronostratigraphic classification, and correlation problems between provinces. Further development of the Permian chronostratigraphic scale should focus on GSSP selection for the remaining, undefined stage bases, definition and characterization of substages, and further integration of the Permian chronostratigraphic scale with radioisotopic, magnetostratigraphic and chemostratigraphic tools for calibration and correlation.

Abstract: Permian rugose corals underwent evolutionary episodes of assemblage changeover, biogeographical separation and extinction, which are closely related to geological events during this time. Two coral realms were recognized, the Tethyan Realm and the Cordilleran–Arctic–Uralian Realm. These are characterized by the families Kepingophyllidae and Waagenophyllidae during the Cisuralian, Waagenophyllidae in the Guadalupian and the subfamily Waagenophyllinae in the Lopingian, and the families Durhaminidae and Kleopatrinidae during the Cisuralian and major disappearance of colonial and dissepimented solitary rugose corals from the Guadalupian to the Lopingian, respectively. The development of these coral realms is controlled by the geographical barrier resulting from the Pangaea formation. According to the changes in the composition and diversity of the Permian rugose corals, a changeover event might have occurred at the end-Sakmarian and is characterized by the mixed Pennsylvanian and Permian faunas to typical Permian faunas, probably related to a global regression. In addition, three extinction events are present at the end-Kungurian, the end-Guadalupian and the end-Permian, which are respectively triggered by the northward movement of Pangaea, the Emeishan volcanic eruptions and subsequent global regression, and the global climate warming induced by the Siberian Traps eruption.