Evolutionary changes of calcareous nannofossils during the past 200 million years based on the crystallographic analysis

本研究旨在通过对钙质纳米化石中方解石晶体的分析来阐明钙质纳米浮游生物的进化。主要研究结果如下：(1)晚三叠世钙质纳米浮游生物出现后，主要的钙质纳米化石分类群立即发生了多样化。(2)某些形态和晶体变化的事件可能与过去的全球环境变化相吻合。

This study aims at clarifying calcareous nannoplankton evolution based on the analysis of calcite crystals forming calcareous nannofossils. The main results are as follows;1) Major calcareous nannofossil taxa had diversified immediately after calcareous nannoplanktons appeared at the late Triassic.2) The events of some morphologic and crystallographic changes may coincide with past global environmental changes.