The Paleogene Period

All Paleocene stages (i.e. Danian, Selandian and Thanetian) have formally ratified definitions, and so have the Ypresian and Lutetian Stages in the Eocene and the Rupelian Stage in the Oligocene. The Bartonian, Priabonian and Chattian Stages are not yet formally defined. After the global Cretaceous–Paleogene boundary catastrophy and biotic crisis, stratigraphically important marine microfossils start new evolutionary trends, and on land the now flourishing mammals offer a potential for stratigraphic zonation. During the Paleogene the global climate, being warm until the late Eocene, shows a significant cooling trend culminating in a major cooling event in the beginning of the Oligocene, preparing the conditions for modern life and climate. Unraveling orbitally tuned cyclic sedimentation series, calibrated to the geomagnetic polarity and biostratigraphic scales, have considerably improved the resolution of the Paleogene time scale.status: publishe