Middle Permian foraminifers from the Zhabuye and Xiadong areas in the central Lhasa Block and their paleobiogeographic implications

•Foraminifer Shanita is found in the central part of the Lhasa Block.•Fusuline Nankinella-Chusenella assemblage was endemic in the Lhasa and Tengchong Blocks.•Both the Bangong-Nujiang Ocean and the Neotethys Ocean would have opened before the Middle Permian.