stratigraphic intervals
   (System) †Triassic (251.902 - 201.3 Ma)
     (Series) †Lower (251.902 - 247.2 Ma)
       (Stage) †Olenekian (251.2 - 247.2 Ma)
         1 (Substage) †Spathian
         2 (Substage) †Smithian