POPULATION DYNAMICS OF DALMANELLA TESTUDINARIA AND DORYTRETA LONGICRURA (BRACHIOPODS) OF LATE ORDOVICIAN HIRNANTIA FAUNA FROM NORTHWESTERN GUIZHOU, SW CHINA

• 黔西北晚奥陶世Dalmanella testudinaria及Dorytreta longicrura(腕足类)居群动态学研究