stratigraphic intervals
Count: [*†*] 2; †295
   (System) †Cambrian (541.0 - 485.4 Ma)
  Count: [†*] †34
     (Series) †Middle (509 - 497 Ma) see Series Series 3 (509 - 497 Ma)
    Count: [†*] †10
       (Stage) †lower Middle
      Count: [†*] †2
         (Substage) †upper
        Count: -