(Table 1) Calcareous nannofossils from ODP Hole 133-815A@en

Species abundances: V (very rare) = <1 specimen per 50 fields (<0.04%), R (rare) = 1 specimen per 11-50 fields (~0.04%-0.2%), F (few) = 1 specimen per 2-10 fields (~0.2%-1%), C (common) = 1-5 specimens per field (~1%-5%), A (abundant) = 6-25 specimens per field (~5%-25%), W (very abundant) = >25 specimens per field (>25%), - = absent.物种丰度分级标准如下：极稀有（V, very rare）：每50个视野内标本数不足1个（占比<0.04%）；稀有（R, rare）：每11~50个视野内出现1个标本，占比约0.04%~0.2%；偶见（F, few）：每2~10个视野内出现1个标本，占比约0.2%~1%；常见（C, common）：每个视野内可见1~5个标本，占比约1%~5%；丰富（A, abundant）：每个视野内可见6~25个标本，占比约5%~25%；极丰富（W, very abundant）：每个视野内可见25个以上标本，占比>25%；符号"-"代表未检出标本。