stratigraphic intervals
   (System) †Cretaceous (145.0 - 66.0 Ma)
     (Series) †Upper (100.5 - 66.0 Ma)
       (Subseries) †Senonian
         (Stage) †Maastrichtian (72.1 - 66.0 Ma)
           1 (Biozone) †neuberigicus Zone
           2 (Biozone) †tridens Zone