A Kungurian (Early Permian) Panthalassan brachiopod fauna from Hatahoko in the Mino Belt, central Japan

要旨

Twelve brachiopod species are described from the Cisuralian (Early Permian) Kungurian horizon of a large limestone block in the Middle Jurassic accretionary complex at Hatahoko in the Mino Belt, central Japan. Most species of the Hatahoko fauna are known from the Kungurian to lowest Guadalupian (Middle Permian) of West Texas, U.S.A. The Kungurian age is also indicated by the associated conodonts in the same limestone block. The Hatahoko brachiopod fauna, as well as some other previously-reported Guadalupian brachiopod faunas, exhibits a very strong paleobiogeographical affinity with the faunas in West Texas, U.S.A. Therefore it can be interpreted as a fauna which inhabited reef-seamount complexes close to North America in the mid-equatorial region of the Panthalassa in the late Early Permian, rifted westwards thousands of kilometers, and finally accreted onto the Japanese Island when the Western Pacific Plate subducted beneath the Eurasian Plate during the Jurassic.

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