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 where native horses and camels were wiped out. In July 2018, a team of Russian scientists in collaboration with Princeton University announced that they had brought two female nematodes frozen in permafrost, from around 42,000 years ago, back to life. The two nematodes, at the time, were the oldest confirmed living animals on the planet. The evolution of anatomically modern humans took place during the Pleistocene. In the beginning of the Pleistocene "Paranthropus" species are still present, as well as early human ancestors, but during the lower Palaeolithic they disappeared, and the only hominin species found in fossilic records is