Mid-Permian Fusulinoidean Territories in Panthalassa

Abstract

Two evolutionary lineages of the Neoshwagerinidae are recognized in the East TethysPanthalassa region in the mid-Permian time. These are the Misellina-Cancellina-ColaniaLepidolina and Misellina-Maklaya-Neoschwagerina-Yabeina evolutionary lineages. They formed distinctly isolated habitats in the Panthalassa region and are named the Colania-Lepidolina and Neoschwagerina-Yabeina territories, respectively. The paleogeographic distribution of the two territories is newly presented with an analysis of the Circum-Pacific accretionary complex combining the fusulinoidean faunas in mid-oceanic paleo-atoll limestones and the timing of their accretion clarified by radiolarian fossils. It is concluded that the Colania-Lepidolina territory expanded into a paleo-equatorial area in mid-Panthalassa with the Neoschwagerina-Yabeina territory at its southern side in the southern hemisphere. In East Paleo-Tethys, South China and Indochina continental blocks which were isolated in equatorial regions throughout the Permian period are striking territories characterized by an extension of the Lepidolina of the ColaniaLepidolina evolutionary lineage. On the Japanese Islands, Kurosegawa, Hida Gaien, South Kitakami and Maizuru belts are also characterized by the occurrence of Lepidolina.