Therefore, the Pleistocene is currently an epoch of both the longer Neogene and the shorter Quaternary.
The proposal of INQUA is to extend the beginning of the Pleistocene to the beginning of the Gelasian Stage, shortening the Pliocene, and ending the Neogene with the revised end of the Pliocene.
It is estimated that, at maximum glacial extent, 30 percent of the Earth's surface was covered by ice.
In addition, a zone of permafrost stretched southward from the edge of the glacial sheet, a few hundred kilometers in North America, and several hundred in Eurasia.
GSSPs are generally, but not always, based on paleontological changes.