Orbitally tuned cyclic sedimentation series, calibrated to the geomagnetic polarity and biostratigraphic scales, have considerably improved the resolution of the Paleogene time scale.
Fossil teeth from Ethiopia reveal details of hippos’ rise to dominance in Africa, including a newly-discovered transitional species and a tight connection with the rise of modern grasses.
–Magnetostratigraphy is the science of reading the prehistoric record of changes to the Earth’s magnetic field.
As time has gone on, varying conditions of our magnetic field have corresponded with particular time periods.
After the global catastrophe and biotic crisis at the Cretaceous–Paleogene boundary, stratigraphically important marine microfossils started new evolutionary trends, and on land the now flourishing mammals offer a potential for stratigraphic zonation.