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
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
B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 view
M. O. Woodburne. 1987. A prospectus of the North American Mammal Ages. In: Woodburne, M. O. (ed.), Cenozoic Mammals of North America. University of California Press, Berkelery, CA 285-290 view
J. Alroy. 2000. New methods for quantifying macroevolutionary patterns and processes. Paleobiology 26(4):707-733 view
J. Palfy, P. L. Smith, and J. K. Mortensen. 2000. A U-Pb and 40Ar/39Ar time scale for the Jurassic. Canadian Journal of Earth Sciences 37(6):923-944 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 126662 collections

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International Chronostratigraphic Timescale			Ordovician of Britain				Ordovician of the Baltic				Ordovician of Ibero-Bohemia
Ordovician	Late Ordovician	Hirnantian	Ashgill	Hirnantian			Harju	Porkuni			Kosovian				443.8
		Katian		Rawtheyan				Pirgu			Kralodvorian	Bohdalec †			445.2
				Cautleyan											448.9 *
				Pusgillian											449.3 *
			Caradoc	Streffordian	Onnian †			Vormsi							449.6 *
								Vormsi			Berounian				449.7 *
								Nabala	Johvi †						450 *
							Viru	Rakvere							450.6 *
				Cheneyan				Rakvere							451.5 *
				Cheneyan				Oandu							452 *
				Burrellian				Oandu							452.7 *
		Sandbian						Keila	Idavere †						453
					Actonian †			Keila							453.2 *
					Actonian †			Haljala							453.9
					Marshbrookian †	Woolstonian †									454.2 *
					Longvillian †										455.2 *
													Zahorany †/Vinice	Letna †	456.2 *
								Kukruse							456.4 *
				Aurelucian											456.8 *
					Soudleyan †/Harnagian/Costonian										457.4 *
								Uhaku	Aluoja †						457.5 *
												Liben †			458 *
	Middle Ordovician	Darriwilian	Llanvirn	Llandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn											458.4
											Dobrotivian				458.5 *
								Lasnamagi			Dobrotivian				458.9 *
								Lasnamagi			Oretanian				459.7 *
								Aseri							460.4 *
				Abereiddian/Early Llanvirn											461.3 *
												Sarka †			461.7 *
							Oeland	Kunda							462.9 *
								Kunda	Valaste †/Hunderum						464.3 *
								Volkhov		Langevoja †/Vaana/Saka					467.1 *
		Dapingian										Klabava †			467.3
											Arenigian				468
			Arenig	Fennian											468.4 *
								Billingen							469.3 *
	Early Ordovician	Floian													470
									Latorp †						470.1 *
				Whitlandian											471.1 *
				Whitlandian				Hunneberg							473.7 *
				Moridunian											474.3 *
		Tremadocian	Tremadoc	Migneintian							Tremadocian				477.7
				Cressagian											480.8 *
								Varangu							481.3 *
								Pakerort							482.2 *
								Pakerort							485 *
															485.4 *
															486.3
															486.5