PBDB Interval

International Chronostratigraphic Timescale

The interval definitions in this timescale are derived from the following sources:

K. M. Cohen, S.C. Finney, P.L. Gibbard and J.-X. Fan. 2023. The ICS International Chronostratigraphic Chart v2023/09. view
J. Meng and M. C. McKenna. 1998. Faunal turnovers of Paleogene mammals from the Mongolian Plateau. Nature 394:364-367 view
F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 view
W. B. Harland, R. L. Armstrong, A. V. Cox, L. E. Craig, A. G. Smith and D. G. Smith. 1990. A Geologic Time Scale 1989. view
A. G. Sennikov and V. K. Golubev. 2006. Vyazniki Biotic Assemblage of the Terminal Permian. Paleontological Journal 40(suppl. 4):S475-S481 view
B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 view

There are 59 timescales which overlap this one. show

Interval boundaries marked with * have been interpolated based on the differences between the ages for international timescale boundaries quoted in the source and the currently accepted ages for those boundaries.

Interval names marked with † are no longer in current use.

This timescale is used in the definition of 127245 collections

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International Chronostratigraphic Timescale			Ten Million Year Bins	Ordovician of Ibero-Bohemia				Ordovician of Britain
Ordovician	Late Ordovician	Hirnantian	Ordovician 5	Kosovian				Ashgill	Hirnantian			443.8
		Katian		Kralodvorian	Bohdalec †				Rawtheyan			445.2
									Cautleyan			448.9 *
									Pusgillian			449.3 *
								Caradoc	Streffordian	Onnian †		449.6 *
				Berounian					Streffordian			449.7 *
									Cheneyan			451.5 *
									Burrellian			452.7 *
		Sandbian	Ordovician 4									453
										Actonian †		453.2 *
										Marshbrookian †	Woolstonian †	454.2 *
										Longvillian †		455.2 *
						Zahorany †/Vinice	Letna †					456.2 *
									Aurelucian			456.8 *
										Soudleyan †/Harnagian/Costonian		457.4 *
					Liben †					Soudleyan †/Harnagian/Costonian		458 *
	Middle Ordovician	Darriwilian	Ordovician 3					Llanvirn	Llandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn			458.4
				Dobrotivian								458.5 *
				Oretanian								459.7 *
									Abereiddian/Early Llanvirn			461.3 *
					Sarka †							461.7 *
		Dapingian	Ordovician 2		Klabava †							467.3
				Arenigian								468
								Arenig	Fennian			468.4 *
	Early Ordovician	Floian							Fennian			470
									Whitlandian			471.1 *
									Moridunian			474.3 *
		Tremadocian	Ordovician 1	Tremadocian				Tremadoc	Migneintian			477.7
								Tremadoc	Cressagian			480.8 *
												485 *
												485.4