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. A. Lillegraven and M. C. McKenna. 1986. Fossil mammals from the "Mesaverde" Formation (Late Cretaceous, Judithian) of the Bighorn and Wind River basins, Wyoming, with definitions of Late Cretaceous North American Land-Mammal "Ages". American Museum Novitates 2840:1-68 view
P. L. Gibbard, M. J. Head, and M. J. C. Walker. 2010. Formal ratification of the Quaternary System/Period and the Pleistocene Series/Epoch with a base at 2.58 Ma. Journal of Quaternary Science 25(2):96-102 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
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 127243 collections

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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