"global chronostratigraphic units"
   (Eon) Phanerozoic Eon (541.0 Ma - present)
     (Era) Cenozoic Era (66.0 Ma - present)
       (Sub-era) †Tertiary Sub-era (66.0 - 2.58 Ma) see Period Tertiary Period (66.0 - 2.58 Ma)
         (Period) †Neogene Period (23.03 - 2.58 Ma)
           (Epoch) †Pliocene Epoch (5.333 - 2.58 Ma)
             1 (Stage) †Zanclian Stage
             2 (Stage) †Piacenzian Stage (3.600 - 2.58 Ma)