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
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
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
F. M. Gradstein, F. P. Agterberg, J. G. Ogg, J. Hardenbol, P. Van Veen, J. Thierry, and Z. Huang. 1995. A Triassic, Jurassic, and Cretaceous time scale. SEPM Special Publication 54 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
A. G. Sennikov and V. K. Golubev. 2006. Vyazniki Biotic Assemblage of the Terminal Permian. Paleontological Journal 40(suppl. 4):S475-S481 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 Australia	Ordovician of Britain
Ordovician	Late Ordovician	Hirnantian	Bolindian	Ashgill	Hirnantian			443.8
		Katian			Rawtheyan			445.2
					Cautleyan			448.9 *
			Eastonian		Cautleyan			449 *
					Pusgillian			449.3 *
				Caradoc	Streffordian	Onnian †		449.6 *
					Cheneyan			451.5 *
			Gisbornian		Cheneyan			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	Darriwilian	Llanvirn	Llandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn			458.4
		Darriwilian	Darriwilian		Abereiddian/Early Llanvirn			461.3 *
		Dapingian	Yapeenian		Abereiddian/Early Llanvirn			467.3
			Yapeenian	Arenig	Fennian			468.4 *
			Castlemainian					468.5 *
	Early Ordovician	Floian	Chewtonian					470
			Chewtonian		Whitlandian			471.1 *
			Bendigonian					471.8 *
			Lancefieldian					473.5 *
					Moridunian			474.3 *
		Tremadocian		Tremadoc	Migneintian			477.7
					Cressagian			480.8 *
			Warendian		Cressagian			482.8 *
			Warendian					485 *
								485.4