Researchers Malinverno and Meyers refined the timeline of Earth's magnetic field reversals for 33 to 83 million years ago. They combined seafloor magnetic stripes, radioactive-decay rock dates, and orbit-driven climate cycles as equals, and measured the timeline's uncertainty.
This timeline is a backbone for dating Earth's history. Scientists use it to date geological and biological events and to work out how fast they changed. With its uncertainties now measured, dates built on it become more trustworthy. It also supports dating most of the geological record, where seafloor magnetic records don't exist.
✦ A better calendar for Earth's deep past makes every date that depends on it more honest.