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
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. 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

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 125929 collections

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International Chronostratigraphic Timescale			Ordovician of Australia	Ordovician of North America
Ordovician	Late Ordovician	Hirnantian	Bolindian	Cincinnatian	Gamachian				443.8
		Katian			Gamachian				445.2
					Richmondian				446 *
			Eastonian		Richmondian				449 *
					Maysvillian	Rocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian			449.8 *
					Edenian				450.4 *
				Mohawkian	Chatfieldian				451.1 *
			Gisbornian						452 *
		Sandbian							453
					Turinian				453.7 *
				Whiterockian		Canadian †	Chazyan †/Marmor		457 *
	Middle Ordovician	Darriwilian	Darriwilian						458.4
		Dapingian	Yapeenian						467.3
			Castlemainian						468.5 *
			Castlemainian		Rangerian				469.1 *
	Early Ordovician	Floian	Chewtonian	Ibexian	Blackhillsian		Jeffersonian †	Cassinian †	470
			Bendigonian						471.8 *
			Lancefieldian						473.5 *
					Tulean				473.9 *
		Tremadocian			Tulean				477.7
					Stairsian				480.3 *
					Skullrockian/Demingian				482 *
			Warendian		Skullrockian/Demingian				482.8 *
									485.4
									487.5