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
  • 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
  • J. Meng and M. C. McKenna. 1998. Faunal turnovers of Paleogene mammals from the Mongolian Plateau. Nature 394:364-367 view
  • F. F. Steininger, W. A. Berggren, D. V. Kent, R. L. Bernor, S. Sen and J. Agusti. 1996. Circum-Mediterranean Neogene (Miocene and Pliocene) marine-continental chronologic correlations of European mammal units. The Evolution of Western Eurasian Neogene Mammal Faunas (eds. R. L. Bernor, V. Fahlbusch, and H.-W. Mittmann) 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. 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 126762 collections

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International Chronostratigraphic TimescaleOrdovician of AustraliaOrdovician of Ibero-BohemiaOrdovician of BritainOrdovician of North America
OrdovicianLate OrdovicianHirnantianBolindianKosovianAshgillHirnantianCincinnatianGamachian443.8
KatianKralodvorianBohdalec †Rawtheyan445.2
Richmondian446 *
Cautleyan448.9 *
Eastonian449 *
Pusgillian449.3 *
CaradocStreffordianOnnian †449.6 *
Berounian449.7 *
MaysvillianRocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian449.8 *
Edenian450.4 *
MohawkianChatfieldian451.1 *
Cheneyan451.5 *
Gisbornian452 *
Burrellian452.7 *
Sandbian453
Actonian †453.2 *
Turinian453.7 *
Marshbrookian †Woolstonian †454.2 *
Longvillian †455.2 *
Zahorany †/ViniceLetna †456.2 *
Aurelucian456.8 *
WhiterockianCanadian †Chazyan †/Marmor457 *
Soudleyan †/Harnagian/Costonian457.4 *
Liben †458 *
Middle OrdovicianDarriwilianDarriwilianLlanvirnLlandeilian/Llandeilo/Late Llandeilo/Middle Llandeilo/Early Llandeilo/Late Llanvirn458.4
Dobrotivian458.5 *
Oretanian459.7 *
Abereiddian/Early Llanvirn461.3 *
Sarka †461.7 *
DapingianYapeenianKlabava †467.3
Arenigian468
ArenigFennian468.4 *
Castlemainian468.5 *
Rangerian469.1 *
Early OrdovicianFloianChewtonianIbexianBlackhillsianJeffersonian †Cassinian †470
Whitlandian471.1 *
Bendigonian471.8 *
Lancefieldian473.5 *
Tulean473.9 *
Moridunian474.3 *
TremadocianTremadocianTremadocMigneintian477.7
Stairsian480.3 *
Cressagian480.8 *
Skullrockian/Demingian482 *
Warendian482.8 *
485 *
485.4
487.5