stratigraphic intervals
   (System) †Jurassic (201.3 - 145.0 Ma)
     (Series) †Upper (163.5 - 145.0 Ma)
       (Stage) †Tithonian (152.1 - 145.0 Ma)
         1 (Substage) †Portlandian
         2 (Substage) †elegans-fittoni Zones