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. 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
  • F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 view
  • F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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
  • A. D. Barnosky, M. Holmes, R. Kirchholtes, E. Lindsey, K.C. Maguire, A.W. Poust, M.A. Stegner, J. Sunseri, B. Swartz, J. Swift, N.A. Villavicencio and G. Wogan. 2014. Prelude to the Anthropocene: Two new North American Land Mammal Ages (NALMAs). The Anthropocene Review I(3):225-242 view
  • A. G. Sennikov and V. K. Golubev. 2006. Vyazniki Biotic Assemblage of the Terminal Permian. Paleontological Journal 40(suppl. 4):S475-S481 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

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 126884 collections

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International Chronostratigraphic TimescaleCretaceous North American Land-Mammal AgesCambrian of ChinaNorth American Mammal Subages/ZonesAmmonite Chrons of North AmericaNorth American Land Mammal AgesPermo-Triassic Subages of Eastern EuropeSilurian of North AmericaSilurian of the BalticOrdovician of North America
QuaternaryHoloceneMeghalayanSaintaugustinean0
Santarosean0.0004
Northgrippian0.0042
Greenlandian0.0082
PleistoceneLate PleistoceneSheridanian0.0117
Rancholabrean0.014
Chibanian0.129
Cudahyan/SappanIrvingtonian0.21
Calabrian0.774
Senecan/RexroadianBlancan1.4
Gelasian1.8
NeogenePliocenePiacenzian2.58
Zanclean3.6
Late Hemphillian/late Early Hemphillian/early Early HemphillianHemphillian4.7
MioceneMessinian5.333
Tortonian7.246
Late Clarendonian/Early ClarendonianClarendonian9.4
Serravallian11.63
late Late Barstovian/early Late Barstovian/Early BarstovianBarstovian12.5
Langhian13.82
Burdigalian15.98
Late Hemingfordian/Early HemingfordianHemingfordian16.3
late Late Arikareean/early Late Arikareean/late Early Arikareean/early Early ArikareeanHarrisonianArikareean18.5
Aquitanian20.44
PaleogeneOligoceneChattian23.03
Monroecreekian23.1 *
Geringian24.7 *
Rupelian27.82
Whitneyan29.5
Orellan31.8
EocenePriabonianLate Chadronian/Middle Chadronian/Early ChadronianChadronian33.9
Duchesnean37
Bartonian37.71
Late Uintan/Early UintanUintan39.7
Lutetian41.2
Twinbuttean/Blacksforkian/GardnerbuttianBridgerian46.2
Ypresian47.8
Lostcabinian/Lysitean/Graybullian/SandcouleeanWasatchian50.5
Cf3/Cf2/Cf1Clarkforkian54.9
PaleoceneThanetian56
Ti6/Ti5/Ti4/Ti3/Ti2/Ti1Tiffanian56.2
Selandian59.2
To3/To2/To1Torrejonian60.9
Danian61.6
Pu3/Pu2/Pu1Puercan63.8
CretaceousLate CretaceousMaastrichtianLancian/Edmontonian66
CampanianJudithian/Aquilan72.1
Santonian83.6
Coniacian86.3
Turonian89.8
Cenomanian93.9
Early CretaceousAlbian100.5
Aptian113
Barremian121.4
Hauterivian125.77
Valanginian132.6
Berriasian139.8
JurassicLate JurassicTithonian145
Kimmeridgian149.2
Oxfordian154.8
Middle JurassicCallovian161.5
Bathonian165.3
BajocianEpizigzagiceras168.2
Rotundum/Oblatum/Kirschneri/Crassicostatus/Widebayense168.4
AalenianHowelli/Scissum/Westermanni170.9
Early JurassicToarcianYakounensis/Hillebrandti/Crassicosta174.7
Planulata179.3 *
Arnioceras arnouldi179.8 *
Kanense181.3 *
Carlottense182.3 *
Kunae183.5 *
Pliensbachian184.2
Freboldi185.1 *
Whiteavesi/ImlayiTetraspidoceras186.2 *
189.2 *
Plesechioceras harbledownense/Asteroceras varians/CoronicerasCanadensis190.3 *
Sinemurian192.9
PseudaetomocerasPsiloceras196.4 *
Franziceras/Euphyllites196.5 *
Hettangian199.5
TriassicLate TriassicRhaetian201.4
Norian208.5
Carnian227
Middle TriassicLadinian237
Anisian242
Early TriassicOlenekianVokhmian247.2
Induan251.2
PermianLopingianChanghsingian251.902
WuchiapingianLate Vyatkian/Early Vyatkian254.14
GuadalupianCapitanianLate Severodvinian/Early Severodvinian259.51
WordianLate Urzhumian/Early Urzhumian264.28
RoadianLate Kazanian/Early Kazanian266.9
CisuralianKungurian273.01
Artinskian283.5
Sakmarian290.1
Asselian293.52
CarboniferousPennsylvanianGzhelian298.9
Kasimovian303.7
Moscovian307
Bashkirian315.2
MississippianSerpukhovian323.2
Visean330.9
Tournaisian346.7
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetian382.7
Eifelian387.7
Early DevonianEmsian393.3
Pragian407.6
Lochkovian410.8
SilurianPridoliCayuganOhesaare419.2
Kaugetuma421.7 *
Niagaran422.5 *
LudlowLudfordianKuressaare423
Paadla423.4 *
Gorstian425.6
WenlockHomerianLockportianRootsikula427.4
Jaagarahu429.2 *
Sheinwoodian430.5
Jaani431.8 *
LlandoveryTelychianOntarian433.4
Adavere434 *
Aeronian438.5
Alexandrian438.7 *
Raikkula439.4 *
MedinanClinton440.1 *
440.7 *
Rhuddanian440.8
Juuru441.4 *
OrdovicianLate OrdovicianHirnantianCincinnatianGamachian443.8
Katian445.2
Richmondian446 *
MaysvillianRocklandian †/Shermanian/Ashbyan/Kirkfieldian/Blackriveran/Wildernessian/Trentonian/Franklinian449.8 *
Edenian450.4 *
MohawkianChatfieldian451.1 *
Sandbian453
Turinian453.7 *
WhiterockianCanadian †Chazyan †/Marmor457 *
Middle OrdovicianDarriwilian458.4
Dapingian467.3
Rangerian469.1 *
Early OrdovicianFloianIbexianBlackhillsianJeffersonian †Cassinian †470
Tulean473.9 *
Tremadocian477.7
Stairsian480.3 *
SkullrockianDemingian †482 *
CambrianFurongianStage 10NiucheheanTaoyuanian †485.4
487.5
JiangshanianJiangshanian489.5
PaibianPaibian494
Waergangian †/Youshuanian494.9 *
MiaolingianGuzhangianGuzhangianWangcunian †497
DrumianDrumian500.5
WuliuanWuliuan/Taijangian504.5
Series 2Stage 4Duyunian509
Stage 3Nangaoian514
TerreneuvianStage 2Meishucunian521
Fortunian529
Jinnigian530.7
538.8