A new species of the primitive stromatoporoid Cystostroma from the Ordovician of East Asia

A new species of the most primitive rosenellid stromatoporoid Cystostroma, C. primordia sp. nov. is reported from the Hunghuayuan Formation (Lower Ordovician, Floian) of Guizhou Province in the South China Block and the Duwibong Formation (Middle Ordovician, Darriwilian) of the Taebaeksan Basin in mid-eastern Korea (North China Block). This species is the first representative of the genus found in both the North and South China blocks....