stratigraphic intervals
   (System) †Cretaceous (145.0 - 66.0 Ma)
     (Series) †Lower (145.0 - 100.5 Ma)
       (Subseries) †Neocomian
         1 (Stage) †Hauterivian (132.6 - 129.4 Ma)
         2 (Stage) †Valanginian (139.8 - 132.6 Ma)
         3 (Stage) †Berriasian (145.0 - 139.8 Ma)