Pleistocene The lower boundary of the Pleistocene Series is formally defined magnetostratigraphically as the base of the Matuyama (C2r) chronozone, isotopic stage 103. Above this point there are notable extinctions of the calcareous nanofossils: "Discoaster pentaradiatus" and "Discoaster surculus". The Pleistocene covers the recent period of repeated glaciations. The name Plio-Pleistocene has, in the past, been used to mean the last ice age. The revised definition of the Quaternary, by pushing back the start date of the Pleistocene to 2.58 Ma, results in the inclusion of all the recent repeated glaciations within the Pleistocene. The modern continents were essentially at their
Pleistocene Park region during the Pleistocene but now faces possible extinction in its remaining habitats is the saiga antelope, which can form massive herds that keep the vegetation down. At the edges of these large stretches of grassland could be found more shrub-like terrain and dry conifer forests (similar to taiga). In this terrain the browsers of the Pleistocene were to be found. This group of megafauna included woolly rhinoceros, moose, wapiti, Yukon wild ass, and camels. The more mountainous terrain was occupied by several species of mountain-going animals like the snow sheep. Back in the Pleistocene there was also a great