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. Meng and M. C. McKenna. 1998. Faunal turnovers of Paleogene mammals from the Mongolian Plateau. Nature 394:364-367 view
F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 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
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

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 126610 collections

Show more time

Show linear time

International Chronostratigraphic Timescale			Ordovician of North America					Ordovician of China			Ordovician of the Baltic
Ordovician	Late Ordovician	Hirnantian	Cincinnatian	Gamachian				Hirnantian	Xiaoxita †/Shikou	Wufeng †	Harju	Porkuni			443.8
		Katian		Gamachian				Chientangkiangian				Pirgu			445.2
				Richmondian				Chientangkiangian							446 *
								Neichianshanian/Hanjiang							449.5
												Vormsi			449.6 *
				Maysvillian	Rocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian							Vormsi			449.8 *
				Maysvillian								Nabala	Johvi †		450 *
				Edenian								Nabala			450.4 *
				Edenian							Viru	Rakvere			450.6 *
			Mohawkian	Chatfieldian								Rakvere			451.1 *
												Oandu			452 *
		Sandbian										Keila	Idavere †		453
				Turinian								Keila			453.7 *
												Haljala			453.9
												Kukruse			456.4 *
			Whiterockian		Canadian †	Chazyan †/Marmor						Kukruse			457 *
												Uhaku	Aluoja †		457.5 *
	Middle Ordovician	Darriwilian						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						Dapingian							467.3
				Rangerian											469.1 *
				Rangerian								Billingen			469.3 *
	Early Ordovician	Floian	Ibexian	Blackhillsian		Jeffersonian †	Cassinian †	Yiyangian							470
													Latorp †		470.1 *
												Hunneberg			473.7 *
				Tulean											473.9 *
		Tremadocian						Xinchangian							477.7
										Lianghekou †					477.9 *
				Stairsian											480.3 *
				Stairsian								Varangu			481.3 *
				Skullrockian/Demingian								Varangu			482 *
				Skullrockian/Demingian								Pakerort			482.2 *
															485.4 *
															486.3
															486.5
															487.5