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
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
B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 view
Z.-X. Qiu and Z.-D. Qiu. 1995. Chronological sequence and subdivision of Chinese Neogene mammalian faunas. Palaeogeography, Palaeoclimatology, Palaeoecology 116(1-2):41-70 view
D. H. Erwin and S. A. Bowring. 2004. Cambrian time scale. view
F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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 126324 collections

Show more time

Show linear time

International Chronostratigraphic Timescale			Ordovician of Australia	Ordovician of Britain				Ten Million Year Bins	Cambrian of Siberia	Ordovician of North America					Ordovician of Ibero-Bohemia
Ordovician	Late Ordovician	Hirnantian	Bolindian	Ashgill	Hirnantian			Ordovician 5		Cincinnatian	Gamachian				Kosovian				443.8
		Katian			Rawtheyan						Gamachian				Kralodvorian	Bohdalec †			445.2
					Rawtheyan						Richmondian								446 *
					Cautleyan														448.9 *
			Eastonian		Cautleyan														449 *
					Pusgillian														449.3 *
				Caradoc	Streffordian	Onnian †													449.6 *
															Berounian				449.7 *
											Maysvillian	Rocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian							449.8 *
											Edenian								450.4 *
										Mohawkian	Chatfieldian								451.1 *
					Cheneyan														451.5 *
			Gisbornian		Cheneyan														452 *
					Burrellian														452.7 *
		Sandbian						Ordovician 4											453
						Actonian †													453.2 *
						Actonian †					Turinian								453.7 *
						Marshbrookian †	Woolstonian †												454.2 *
						Longvillian †													455.2 *
																	Zahorany †/Vinice	Letna †	456.2 *
					Aurelucian														456.8 *
										Whiterockian		Canadian †	Chazyan †/Marmor						457 *
						Soudleyan †/Harnagian/Costonian													457.4 *
						Soudleyan †/Harnagian/Costonian										Liben †			458 *
	Middle Ordovician	Darriwilian	Darriwilian	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 *
		Dapingian	Yapeenian					Ordovician 2								Klabava †			467.3
															Arenigian				468
				Arenig	Fennian														468.4 *
			Castlemainian																468.5 *
			Castlemainian								Rangerian								469.1 *
	Early Ordovician	Floian	Chewtonian							Ibexian	Blackhillsian		Jeffersonian †	Cassinian †					470
			Chewtonian		Whitlandian														471.1 *
			Bendigonian																471.8 *
			Lancefieldian																473.5 *
											Tulean								473.9 *
					Moridunian														474.3 *
		Tremadocian		Tremadoc	Migneintian			Ordovician 1							Tremadocian				477.7
					Migneintian						Stairsian								480.3 *
					Cressagian						Stairsian								480.8 *
											Skullrockian/Demingian								482 *
			Warendian																482.8 *
									Mansian †										483.55 *
									Mansian †										485 *
																			485.4
																			487.5