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. 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
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
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
M. Freudenthal. 2006. Mammal Paleogene zones. personal communication 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
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

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 126606 collections

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International Chronostratigraphic Timescale			Ten Million Year Bins	Ordovician of North America
Ordovician	Late Ordovician	Hirnantian	Ordovician 5	Cincinnatian	Gamachian				443.8
		Katian			Gamachian				445.2
					Richmondian				446 *
					Maysvillian	Rocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian			449.8 *
					Edenian				450.4 *
				Mohawkian	Chatfieldian				451.1 *
		Sandbian	Ordovician 4		Chatfieldian				453
					Turinian				453.7 *
				Whiterockian		Canadian †	Chazyan †/Marmor		457 *
	Middle Ordovician	Darriwilian	Ordovician 3						458.4
		Dapingian	Ordovician 2						467.3
		Dapingian			Rangerian				469.1 *
	Early Ordovician	Floian		Ibexian	Blackhillsian		Jeffersonian †	Cassinian †	470
		Floian			Tulean				473.9 *
		Tremadocian	Ordovician 1		Tulean				477.7
					Stairsian				480.3 *
					Skullrockian/Demingian				482 *
									485.4
									487.5