Choristitid brachiopod species from the Upper Carboniferous Nagaiwa Formation, South Kitakami Belt, northeast Japan, and palaeobiogeographical implication

Abstract

Four choristitid brachiopod species were found in the Upper Carboniferous (Moscovian) limestone of the Nagaiwa Formation in the Nagaiwa area, South Kitakami Belt, northeast Japan: Choristites mosquensis Fischer de Waldheim, Choristites jigulensis (Stuckenberg), Parachoristites sp. A, and Parachoristites sp. B. All these species are Boreal-type brachiopods, distributed throughout the Upper Carboniferous (Bashkirian) to lowest Permian (Asselian) of northern and western Russia, central Asia, and Northwest to Northeast China. Therefore, the occurrence of the present choristitid brachiopods suggests that the South Kitakami area was part of the continental shelf along the eastern margin of North China (Sino-Korea) during the Late Carboniferous.