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. 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
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
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

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 126610 collections

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International Chronostratigraphic Timescale			Ordovician of North America					Ordovician of Britain				Ordovician of Australia
Ordovician	Late Ordovician	Hirnantian	Cincinnatian	Gamachian				Ashgill	Hirnantian			Bolindian	443.8
		Katian		Gamachian					Rawtheyan				445.2
				Richmondian					Rawtheyan				446 *
									Cautleyan				448.9 *
									Cautleyan			Eastonian	449 *
									Pusgillian				449.3 *
								Caradoc	Streffordian	Onnian †			449.6 *
				Maysvillian	Rocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian								449.8 *
				Edenian									450.4 *
			Mohawkian	Chatfieldian									451.1 *
									Cheneyan				451.5 *
									Cheneyan			Gisbornian	452 *
									Burrellian				452.7 *
		Sandbian											453
										Actonian †			453.2 *
				Turinian						Actonian †			453.7 *
										Marshbrookian †	Woolstonian †		454.2 *
										Longvillian †			455.2 *
									Aurelucian				456.8 *
			Whiterockian		Canadian †	Chazyan †/Marmor							457 *
										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 *
				Rangerian								Castlemainian	469.1 *
	Early Ordovician	Floian	Ibexian	Blackhillsian		Jeffersonian †	Cassinian †					Chewtonian	470
									Whitlandian			Chewtonian	471.1 *
												Bendigonian	471.8 *
												Lancefieldian	473.5 *
				Tulean									473.9 *
									Moridunian				474.3 *
		Tremadocian						Tremadoc	Migneintian				477.7
				Stairsian					Migneintian				480.3 *
				Stairsian					Cressagian				480.8 *
				Skullrockian/Demingian									482 *
												Warendian	482.8 *
												Warendian	485 *
													485.4
													487.5