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
B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 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
J. I. Raine, A. G. Beu, A. F. Boyes, H. J. Campbell, R. A. Cooper, J. S. Crampton, M. P. Crundwell, C. J. Hollis, and H. E. G. Morgans. 2015. Revised Calibration of the New Zealand Geological Timescale: NZGT2015/1. GNS Science Report 2012(39) 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

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 126152 collections

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International Chronostratigraphic Timescale			Ordovician of China			Ordovician of Britain				Ordovician of Ibero-Bohemia				Ten Million Year Bins
Ordovician	Late Ordovician	Hirnantian	Hirnantian	Xiaoxita †/Shikou	Wufeng †	Ashgill	Hirnantian			Kosovian				Ordovician 5	443.8
		Katian	Chientangkiangian				Rawtheyan			Kralodvorian	Bohdalec †				445.2
							Cautleyan								448.9 *
							Pusgillian								449.3 *
			Neichianshanian/Hanjiang				Pusgillian								449.5
						Caradoc	Streffordian	Onnian †							449.6 *
							Streffordian			Berounian					449.7 *
							Cheneyan								451.5 *
							Burrellian								452.7 *
		Sandbian												Ordovician 4	453
								Actonian †							453.2 *
								Marshbrookian †	Woolstonian †						454.2 *
								Longvillian †							455.2 *
												Zahorany †/Vinice	Letna †		456.2 *
							Aurelucian								456.8 *
								Soudleyan †/Harnagian/Costonian							457.4 *
								Soudleyan †/Harnagian/Costonian			Liben †				458 *
	Middle Ordovician	Darriwilian	Darriwilian	Guniu †/Hulo		Llanvirn	Llandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn							Ordovician 3	458.4
										Dobrotivian					458.5 *
										Oretanian					459.7 *
							Abereiddian/Early Llanvirn								461.3 *
											Sarka †				461.7 *
				Hunjiang †	Dawan †/Daobaowan/Ningkuo						Sarka †				466.3 *
		Dapingian	Dapingian								Klabava †			Ordovician 2	467.3
										Arenigian					468
						Arenig	Fennian								468.4 *
	Early Ordovician	Floian	Yiyangian				Fennian								470
							Whitlandian								471.1 *
							Moridunian								474.3 *
		Tremadocian	Xinchangian			Tremadoc	Migneintian			Tremadocian				Ordovician 1	477.7
					Lianghekou †		Migneintian								477.9 *
							Cressagian								480.8 *
															485 *
															485.4