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
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
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
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			Ten Million Year Bins	Ordovician of China			Ordovician of the Baltic				Ordovician of North America
Ordovician	Late Ordovician	Hirnantian	Ordovician 5	Hirnantian	Xiaoxita †/Shikou	Wufeng †	Harju	Porkuni			Cincinnatian	Gamachian				443.8
		Katian		Chientangkiangian				Pirgu				Gamachian				445.2
				Chientangkiangian								Richmondian				446 *
				Neichianshanian/Hanjiang												449.5
								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 *
								Rakvere			Mohawkian	Chatfieldian				451.1 *
								Oandu								452 *
		Sandbian	Ordovician 4					Keila	Idavere †							453
								Keila				Turinian				453.7 *
								Haljala								453.9
								Kukruse								456.4 *
								Kukruse			Whiterockian		Canadian †	Chazyan †/Marmor		457 *
								Uhaku	Aluoja †							457.5 *
	Middle Ordovician	Darriwilian	Ordovician 3	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	Ordovician 2	Dapingian												467.3
												Rangerian				469.1 *
								Billingen				Rangerian				469.3 *
	Early Ordovician	Floian		Yiyangian							Ibexian	Blackhillsian		Jeffersonian †	Cassinian †	470
									Latorp †							470.1 *
								Hunneberg								473.7 *
												Tulean				473.9 *
		Tremadocian	Ordovician 1	Xinchangian												477.7
						Lianghekou †										477.9 *
												Stairsian				480.3 *
								Varangu				Stairsian				481.3 *
								Varangu				Skullrockian/Demingian				482 *
								Pakerort				Skullrockian/Demingian				482.2 *
																485.4 *
																486.3
																486.5
																487.5