(Table 1) Distribution of early Cretaceous nannofossils in DSDP Hole 77-535@en

Species abundances: V = very abundant (> 10 specimens per field of view at 1560 X), A = abundant (1 to 10 specimens per field), C, common (1 specimen per 2-10 fields), F = few (1 specimen per 11-100 fields), R = rare (1 specimen per 101-1000 fields). - = absent.物种丰度分级标准如下：V = 极丰富（very abundant）：1560倍放大视野下，每视野标本数大于10；A = 丰富（abundant）：每视野可见1~10个标本；C = 常见（common）：每2~10个视野可见1个标本；F = 稀少（few）：每11~100个视野可见1个标本；R = 稀有（rare）：每101~1000个视野可见1个标本；- = 标本缺失。