Aeroniën aerón younger bound -438.5 +|-1.1 Ma Paleozoic Era Aeroniense older bound -440.8 +|-1.2 Ma Phanerozoic Eon Aeronian Age Silurian Period Llandovery Epoch Aeronium Aeronium Base of Aeronian Telychian Age a1.1.3.4.4.2 Aéronien aeron アエロニアン期 Aeron Aeron Aeron Rhuddanian Age Aeronis aeronij aeroniano aeroni Base of Telychian Aeroni Aeronien Aeroniano перон 埃隆期 Geologic Time Scale (2020) Aeronian