"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) (Epoch) †Late Triassic Epoch (237 - 201.3 Ma) (Stage) †Norian Stage (227 - 208.5 Ma)