"global chronostratigraphic units"
   (Eon) Phanerozoic Eon (541.0 Ma - present)
     (Era) †Mesozoic Era (252.17 - 66.0 Ma)
       (Period) †Jurassic Period (201.3 - 145.0 Ma)
         (Epoch) †Dogger Epoch
           1 (Stage) †Aalenian Stage (174.1 - 170.3 Ma)
           2 (Stage) †Bajocian Stage (170.3 - 168.3 Ma)
           3 (Stage) †Bathonian Stage (168.3 - 166.1 Ma)
           4 (Stage) †Callovian Stage (166.1 - 163.5 Ma)