n.[古生]牙形刺；牙形石
The Silurian strata containing abundant conodont fossils are well developed and comformable with the overlying Devonian strata in the Baizitian region, northern Yanbian, Sichuan. 四川省盐边县北部稗子田地区的志留系发育良好，牙形刺化石极为丰富，与上覆泥盆系连续沉积，并呈整合接触。
