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, 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
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
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
J. Palfy, P. L. Smith, and J. K. Mortensen. 2000. A U-Pb and 40Ar/39Ar time scale for the Jurassic. Canadian Journal of Earth Sciences 37(6):923-944 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

Show more time

Show linear time

International Chronostratigraphic Timescale			Ordovician of Britain				Ordovician of China			Ordovician of the Baltic				Ordovician of North America
Ordovician	Late Ordovician	Hirnantian	Ashgill	Hirnantian			Hirnantian	Xiaoxita †/Shikou	Wufeng †	Harju	Porkuni			Cincinnatian	Gamachian				443.8
		Katian		Rawtheyan			Chientangkiangian				Pirgu				Gamachian				445.2
				Rawtheyan											Richmondian				446 *
				Cautleyan															448.9 *
				Pusgillian															449.3 *
				Pusgillian			Neichianshanian/Hanjiang												449.5
			Caradoc	Streffordian	Onnian †						Vormsi								449.6 *
											Vormsi				Maysvillian	Rocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian			449.8 *
											Nabala	Johvi †			Maysvillian				450 *
											Nabala				Edenian				450.4 *
										Viru	Rakvere				Edenian				450.6 *
														Mohawkian	Chatfieldian				451.1 *
				Cheneyan															451.5 *
				Cheneyan							Oandu								452 *
				Burrellian							Oandu								452.7 *
		Sandbian									Keila	Idavere †							453
					Actonian †														453.2 *
															Turinian				453.7 *
											Haljala								453.9
					Marshbrookian †	Woolstonian †													454.2 *
					Longvillian †														455.2 *
											Kukruse								456.4 *
				Aurelucian															456.8 *
														Whiterockian		Canadian †	Chazyan †/Marmor		457 *
					Soudleyan †/Harnagian/Costonian														457.4 *
					Soudleyan †/Harnagian/Costonian						Uhaku	Aluoja †							457.5 *
	Middle Ordovician	Darriwilian	Llanvirn	Llandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn			Darriwilian	Guniu †/Hulo			Uhaku								458.4
											Lasnamagi								458.9 *
											Aseri								460.4 *
				Abereiddian/Early Llanvirn							Aseri								461.3 *
										Oeland	Kunda								462.9 *
												Valaste †/Hunderum							464.3 *
								Hunjiang †	Dawan †/Daobaowan/Ningkuo										466.3 *
											Volkhov		Langevoja †/Vaana/Saka						467.1 *
		Dapingian					Dapingian												467.3
			Arenig	Fennian															468.4 *
															Rangerian				469.1 *
											Billingen				Rangerian				469.3 *
	Early Ordovician	Floian					Yiyangian							Ibexian	Blackhillsian		Jeffersonian †	Cassinian †	470
												Latorp †							470.1 *
				Whitlandian															471.1 *
											Hunneberg								473.7 *
															Tulean				473.9 *
				Moridunian															474.3 *
		Tremadocian	Tremadoc	Migneintian			Xinchangian												477.7
									Lianghekou †										477.9 *
															Stairsian				480.3 *
				Cressagian															480.8 *
											Varangu								481.3 *
											Varangu				Skullrockian/Demingian				482 *
											Pakerort								482.2 *
											Pakerort								485 *
																			485.4 *
																			486.3
																			486.5
																			487.5