"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) †Early Devonian Epoch (419.2 - 393.3 Ma) (Stage) †Lochkovian Stage (419.2 - 410.8 Ma)