Carboniferous Period 前期ミシシッピアン紀 Early Mississippian Geologic Time Scale (2018) younger bound -346.7 +|-0.4 Ma Base of Carboniferous Devonian Period 早密西西比世 Paleozoic Era Mississippian Sub-period Late Devonian Epoch Tournaisian Age Base of Middle Mississippian Base of Visean older bound -358.9 +|-0.4 Ma Middle Mississippian Epoch Lower Mississippian Famennian Age ミシシッピ川下流 下密西西比州 Phanerozoic Eon Visean Age Early Mississippian Epoch x1.1.3.2.2.3