PBDB Interval Range

454.2 - 449.6 Ma

International Chronostratigraphic Timescale			Ordovician of Britain
Ordovician	Late Ordovician	Hirnantian	Ashgill	Hirnantian			443.8
		Katian		Rawtheyan			445.2
				Cautleyan			448.9 *
				Pusgillian			449.3 *
			Caradoc	Streffordian	Onnian †		449.6 *
				Cheneyan			451.5 *
				Burrellian			452.7 *
		Sandbian					453
					Actonian †		453.2 *
					Marshbrookian †	Woolstonian †	454.2 *
					Longvillian †		455.2 *
				Aurelucian	Longvillian †		456.8 *
				Aurelucian	Soudleyan †/Harnagian/Costonian		457.4 *
	Middle Ordovician	Darriwilian	Llanvirn	Llandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn			458.4
		Darriwilian		Abereiddian/Early Llanvirn			461.3 *
		Dapingian		Abereiddian/Early Llanvirn			467.3
		Dapingian	Arenig	Fennian			468.4 *
	Early Ordovician	Floian		Fennian			470
				Whitlandian			471.1 *
				Moridunian			474.3 *
		Tremadocian	Tremadoc	Migneintian			477.7
			Tremadoc	Cressagian			480.8 *
							485 *
							485.4