Abstract An evaluation of the potential geodynamic connections between the evolution of Paleozoic oceans in NW Gondwana and NE Gondwana is challenging. Until recently, most syntheses emphasized only two Paleozoic oceans (the Proto-Tethys and the Palaeo-Tethys) in the east Tethys realm. However, the discovery of early Paleozoic ophiolites along Palaeo-Tethys sutures located south of Proto-Tethys sutures challenges these traditional views. After a comprehensive review of relevant early Paleozoic tectonomagmatic events, we herein recognize and propose a model for the tectonic evolution of a hitherto unrecognized early Paleozoic ocean, which we call the Proto-Qiangtang Ocean. This ocean was short lived; it opened in the late Cambrian, began to subduct in the Middle Ordovician, and closed diachronously westwards between the Late Ordovician and the middle Silurian. Its closure by middle Silurian time indicates that was a spatially and temporally distinct ocean from the Palaeo-Tethys Ocean. The early tectonic evolution of the Proto-Qiangtang Ocean shares many characteristics with that of the Rheic Ocean. Both opened in the late Cambrian in the back-arc region of the Iapetus–Proto-Tethys Ocean, and the Proto-Qiangtang Ocean is considered to represent the eastern extension of the Rheic Ocean. This correlation has important implications for the Paleozoic tectonic evolution and palaeogeography of northern Gondwana.

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.