"global chronostratigraphic units"
   (Eon) Phanerozoic Eon (541.0 Ma - present)
     (Era) †Mesozoic Era (252.17 - 66.0 Ma)
       (Period) †Triassic Period (251.902 - 201.3 Ma)
         1 (Epoch) †Scythian Epoch
         2 (Epoch) †Mid Triassic Epoch (247.2 - 237 Ma)
         3 (Epoch) †Late Triassic Epoch (237 - 201.3 Ma)