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
Superman: The Animated Series off into a new animated series, "Justice League", which also featured other popular DC Comics characters, including Wonder Woman, The Flash, Green Lantern, Martian Manhunter, and Hawkgirl which spawned a sequel series "Justice League Unlimited". Originally producer Bruce Timm wanted the show to have a more 1940s Fleischer Studios "Superman"-cartoon feel. Another original character design sheet showed the characters in a stylised 1950s style (not unlike that of the live-action "Adventures of Superman" TV series), suggesting that the producers also considered setting the series during that period, or possibly ending up like "Batman: The Animated Series" (set during modern times,