25 years of Ocean Drilling have advanced the stratigraphy. The Late Mesozoic to Cenozoic zonation schemes of calcareous nannofossil,foraminifera , radiolarian and dinoflagellate were established on basis of the information gained from DSDP and ODP,and the resolution of stratigraphic division can be as high as less than 0. 1Ma using numerous marine bio-datum events.
    New techniques such as hydraulic piston coring was applied to DSDP Leg 73 in the South Atlantic Ocean and yielded a tight calibration between biotratigraphy and magnetic polarity time scale. Since then, biostratigraphic datum has been correlated with magnetostratigraphic chron for each leg of DSDP and ODP and a high resolution magneto-biochronologic schemes of Late Mesozoic and Cenozoic has been established. As a result, some theoretical topics such as origin,migration,evolution and extinction of microorganism can be explored using data from legs located at various latitudes.