Until further notice, the authors of manuscripts submitted to Micropaleontology and Stratigraphy will have the choice of two options in characterizing the age of later Cenozoic events and strata. The options are: - 2.6 Ma option: Pleistocene defined in the Gelasian GSSP. This option conforms to the recent proposal by INQUA, subsequently approved by IUGS (Gibbard, Head and Walker, 2010), in which the recognition of a formal Quaternary Period/System in place of the latter part of the Neogene leads to redefining the base of the Pleistocene Epoch/Series in the San Nicolá GSSP of the Gelasian Age/Stage, currently calibrated to 2.588 (2.6) Ma. - 1.8 Ma option: Pleistocene defined in the Calabrian GSSP. This option conforms to the previous usage of Pleistocene, most recently exemplified in “GTS 2004” (Gradstein, Ogg and Smith, 2004), wherein the Pleistocene is defined in the Vrica GSSP of the Calabrian Age/Stage, currently calibrated to 1.801 (1.8) Ma.