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
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
B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 view
J. Meng and M. C. McKenna. 1998. Faunal turnovers of Paleogene mammals from the Mongolian Plateau. Nature 394:364-367 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 126973 collections

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International Chronostratigraphic Timescale			Ordovician of Britain				Ordovician of Australia
Ordovician	Late Ordovician	Hirnantian	Ashgill	Hirnantian			Bolindian	443.8
		Katian		Rawtheyan				445.2
				Cautleyan				448.9 *
				Cautleyan			Eastonian	449 *
				Pusgillian				449.3 *
			Caradoc	Streffordian	Onnian †			449.6 *
				Cheneyan				451.5 *
				Cheneyan			Gisbornian	452 *
				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			Darriwilian	458.4
		Darriwilian		Abereiddian/Early Llanvirn			Darriwilian	461.3 *
		Dapingian		Abereiddian/Early Llanvirn			Yapeenian	467.3
			Arenig	Fennian			Yapeenian	468.4 *
							Castlemainian	468.5 *
	Early Ordovician	Floian					Chewtonian	470
				Whitlandian			Chewtonian	471.1 *
							Bendigonian	471.8 *
							Lancefieldian	473.5 *
				Moridunian				474.3 *
		Tremadocian	Tremadoc	Migneintian				477.7
				Cressagian				480.8 *
				Cressagian			Warendian	482.8 *
							Warendian	485 *
								485.4