A Comparative Study on the Permian Invertebrate Marine Fossils between the Arctic and the Tethys

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Based on the occurrence data of the Permian marine invertebrate fossils both in the Arctic (mainly from Spitsbergen) and in the Tethys (from Japan, China, Southeast Asia, India, Pakistan, Iran, Turkey, Greece, Yugoslavia, Italy), it becomes evident that through the Permian Period there is a distinct difference between the marine invertebrate faunas in the Arctic Sea area and those in the Tethyan Sea area. In the Arctic region, the region of Franklinian Sea and adjacent shelves, the known Permian invertebrate faunas from Novaya Zemlya to Spitsbergen, Greenland and Canadian Arctic Islands have affinities with faunas of the Russian Platform, Uralian Sea and Eastern Siberia. They also indicate strong relations to those of the Zechstein Sea area of northern Europe. Invertebrate fossil assemblages of the Arctic are comparatively uniform within the province, while the assemblages of the Tethys are fairly different. Comparison of invertebrate fossil assemblages indicate that the Tethys Province can be fundamentally divided into three provinces, i. e. The Angara-Tethyan, the Middle-Tethyan and Gondwana-Tethyan Subprovinces from north to south in the Permian time. Among them the faunas from the Angara-Tethyan Subprovince usually include a lot of Arctic-type ones, while those of the Middle-Tethyan do contain none of the Arctic-type ones except for some bivalves. Faunas of the Gondwana-Tethyan Subprovince are considered to have some relationship with the Arctic ones in generic level, nevertheless do not contain any common species. This fact means that the climate in the Gondwana-Tethyan Subprovince and the Arctic Province was cooler compared with that in the Middle-Tethyan Subprovince. Through the Permian time faunal provincialism between the Arctic and the Tethys became more evident in the Late Permian compared with that in the Early Permian.