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. Meng and M. C. McKenna. 1998. Faunal turnovers of Paleogene mammals from the Mongolian Plateau. Nature 394:364-367 view
A. D. Barnosky, M. Holmes, R. Kirchholtes, E. Lindsey, K.C. Maguire, A.W. Poust, M.A. Stegner, J. Sunseri, B. Swartz, J. Swift, N.A. Villavicencio and G. Wogan. 2014. Prelude to the Anthropocene: Two new North American Land Mammal Ages (NALMAs). The Anthropocene Review I(3):225-242 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, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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 126585 collections

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International Chronostratigraphic Timescale			Ten Million Year Bins	Ordovician of China			Ordovician of Ibero-Bohemia
Ordovician	Late Ordovician	Hirnantian	Ordovician 5	Hirnantian	Xiaoxita †/Shikou	Wufeng †	Kosovian				443.8
		Katian		Chientangkiangian		Wufeng †	Kralodvorian	Bohdalec †			445.2
				Neichianshanian/Hanjiang			Kralodvorian				449.5
							Berounian				449.7 *
		Sandbian	Ordovician 4								453
									Zahorany †/Vinice	Letna †	456.2 *
								Liben †			458 *
	Middle Ordovician	Darriwilian	Ordovician 3	Darriwilian	Guniu †/Hulo						458.4
							Dobrotivian				458.5 *
							Oretanian				459.7 *
								Sarka †			461.7 *
					Hunjiang †	Dawan †/Daobaowan/Ningkuo		Sarka †			466.3 *
		Dapingian	Ordovician 2	Dapingian				Klabava †			467.3
		Dapingian		Dapingian			Arenigian				468
	Early Ordovician	Floian		Yiyangian			Arenigian				470
		Tremadocian	Ordovician 1	Xinchangian			Tremadocian				477.7
		Tremadocian	Ordovician 1	Xinchangian		Lianghekou †	Tremadocian				477.9 *
											485.4