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, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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
F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 view
M. Kretzoi. 1942. Necroteuthis n. g. (Ceph. Dibr., Necroteuthidae N. F.) aus dem Oligozän von Budapest und das system der Dibranchiata. Földtani Közlöny 72:125-238 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			Ordovician of North America					Ordovician of Ibero-Bohemia				Ordovician of Britain
Ordovician	Late Ordovician	Hirnantian	Cincinnatian	Gamachian				Kosovian				Ashgill	Hirnantian			443.8
		Katian		Gamachian				Kralodvorian	Bohdalec †				Rawtheyan			445.2
				Richmondian									Rawtheyan			446 *
													Cautleyan			448.9 *
													Pusgillian			449.3 *
												Caradoc	Streffordian	Onnian †		449.6 *
								Berounian								449.7 *
				Maysvillian	Rocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian											449.8 *
				Edenian												450.4 *
			Mohawkian	Chatfieldian												451.1 *
													Cheneyan			451.5 *
													Burrellian			452.7 *
		Sandbian														453
														Actonian †		453.2 *
				Turinian										Actonian †		453.7 *
														Marshbrookian †	Woolstonian †	454.2 *
														Longvillian †		455.2 *
										Zahorany †/Vinice	Letna †					456.2 *
													Aurelucian			456.8 *
			Whiterockian		Canadian †	Chazyan †/Marmor										457 *
														Soudleyan †/Harnagian/Costonian		457.4 *
									Liben †					Soudleyan †/Harnagian/Costonian		458 *
	Middle Ordovician	Darriwilian										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							Klabava †							467.3
								Arenigian								468
												Arenig	Fennian			468.4 *
				Rangerian												469.1 *
	Early Ordovician	Floian	Ibexian	Blackhillsian		Jeffersonian †	Cassinian †									470
				Blackhillsian									Whitlandian			471.1 *
				Tulean									Whitlandian			473.9 *
													Moridunian			474.3 *
		Tremadocian						Tremadocian				Tremadoc	Migneintian			477.7
				Stairsian									Migneintian			480.3 *
				Stairsian									Cressagian			480.8 *
				Skullrockian/Demingian									Cressagian			482 *
				Skullrockian/Demingian												485 *
																485.4
																487.5