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
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
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
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
F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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 126848 collections

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International Chronostratigraphic Timescale			Ordovician of China			Ordovician of the Baltic
Ordovician	Late Ordovician	Hirnantian	Hirnantian	Xiaoxita †/Shikou	Wufeng †	Harju	Porkuni			443.8
		Katian	Chientangkiangian		Wufeng †		Pirgu			445.2
			Neichianshanian/Hanjiang				Pirgu			449.5
							Vormsi			449.6 *
							Nabala	Johvi †		450 *
						Viru	Rakvere			450.6 *
							Oandu			452 *
		Sandbian					Keila	Idavere †		453
							Haljala			453.9
							Kukruse			456.4 *
							Uhaku	Aluoja †		457.5 *
	Middle Ordovician	Darriwilian	Darriwilian	Guniu †/Hulo			Uhaku			458.4
							Lasnamagi			458.9 *
							Aseri			460.4 *
						Oeland	Kunda			462.9 *
								Valaste †/Hunderum		464.3 *
				Hunjiang †	Dawan †/Daobaowan/Ningkuo					466.3 *
							Volkhov		Langevoja †/Vaana/Saka	467.1 *
		Dapingian	Dapingian				Volkhov			467.3
		Dapingian	Dapingian				Billingen			469.3 *
	Early Ordovician	Floian	Yiyangian							470
								Latorp †		470.1 *
							Hunneberg			473.7 *
		Tremadocian	Xinchangian							477.7
					Lianghekou †					477.9 *
							Varangu			481.3 *
							Pakerort			482.2 *
										485.4 *
										486.3
										486.5