Katiën katiano International Chronostratigraphic Chart (2017) Ordovician Period Hirnantian Age Base of Hirnantian Upper Ordovician Epoch younger bound -445.2 +|-1.4 Ma kat kat Phanerozoic Eon kati Kat Kat Kat Katiense katij Paleozoic Era older bound -453 +|-0.7 Ma Katian カティアン期 Katium Katium Кат Katiano a1.1.3.5.1.2 Base of Katian Katian Age Sandbian Age Kati 凯迪期 Katien Katien Katis