"global chronostratigraphic units" (Eon) Phanerozoic Eon (541.0 Ma - present) (Era) †Paleozoic Era (541.0 - 251.902 Ma) (Period) †Devonian Period (419.2 - 358.9 Ma) (Epoch) †Mid Devonian Epoch (393.3 - 382.7 Ma) (Stage) †Givetian Stage (387.7 - 382.7 Ma)