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
  • 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
  • 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
  • A. G. Sennikov and V. K. Golubev. 2006. Vyazniki Biotic Assemblage of the Terminal Permian. Paleontological Journal 40(suppl. 4):S475-S481 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 128360 collections

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International Chronostratigraphic TimescaleTen Million Year BinsCretaceous North American Land-Mammal AgesObsolete Names for ICS UnitsCambrian of AustraliaCenozoic SubepochsCambrian of BritainDevonian of Eastern North AmericaOrdovician of Ibero-BohemiaPermo-Triassic Subages of Eastern EuropeObsolete Carboniferous Ages of China
QuaternaryHoloceneMeghalayanCenozoic 60
Northgrippian0.0042
Greenlandian0.0082
PleistoceneLate PleistoceneLate Pleistocene0.0117
ChibanianMiddle Pleistocene0.129
CalabrianEarly Pleistocene0.774
Gelasian1.8
NeogenePliocenePiacenzianTertiary †Late Pliocene2.58
ZancleanEarly Pliocene3.6
MioceneMessinianLate Miocene5.333
Tortonian7.246
SerravallianCenozoic 5Middle Miocene11.63
Langhian13.82
BurdigalianEarly Miocene15.98
Aquitanian20.44
PaleogeneOligoceneChattianCenozoic 4Late Oligocene23.03
RupelianEarly Oligocene27.82
EocenePriabonianCenozoic 3Late Eocene33.9
BartonianMiddle Eocene37.71
LutetianCenozoic 241.2
YpresianEarly Eocene47.8
PaleoceneThanetianCenozoic 1Late Paleocene56
SelandianMiddle Paleocene59.2
DanianEarly Paleocene61.6
CretaceousLate CretaceousMaastrichtianCretaceous 8Lancian/Edmontonian66
CampanianCretaceous 7Judithian/Aquilan72.1
SantonianCretaceous 683.6
Coniacian86.3
Turonian89.8
CenomanianCretaceous 593.9
Early CretaceousAlbianCretaceous 4100.5
AptianCretaceous 3113
BarremianCretaceous 2121.4
Hauterivian125.77
ValanginianCretaceous 1132.6
Berriasian139.8
JurassicLate JurassicTithonianJurassic 6145
KimmeridgianJurassic 5149.2
Oxfordian154.8
Middle JurassicCallovian161.5
BathonianJurassic 4165.3
Bajocian168.2
AalenianJurassic 3170.9
Early JurassicToarcian174.7
PliensbachianJurassic 2184.2
SinemurianJurassic 1192.9
Hettangian199.5
TriassicLate TriassicRhaetianTriassic 4201.4
Norian208.5
CarnianTriassic 3227
Middle TriassicLadinianTriassic 2237
Anisian242
Early TriassicOlenekianTriassic 1Vokhmian247.2
Induan251.2
PermianLopingianChanghsingianPermian 4251.902
WuchiapingianLongtanian †Late Vyatkian/Early Vyatkian254.14
GuadalupianCapitanianLate Severodvinian/Early Severodvinian259.51
WordianLate Urzhumian/Early Urzhumian264.28
RoadianPermian 3Late Kazanian/Early Kazanian266.9
CisuralianKungurianPermian 2273.01
Artinskian283.5
Sakmarian290.1
AsselianPermian 1293.52
CarboniferousPennsylvanianGzhelianCarboniferous 5Mapingian †298.9
Kasimovian303.7
305.9
MoscovianCarboniferous 4307
Bashkirian315.2
MississippianSerpukhovianCarboniferous 3323.2
ViseanCarboniferous 2330.9
TournaisianCarboniferous 1346.7
DevonianLate DevonianFamennianDevonian 5Conewangan/Conneautan/Canadaway358.9
FrasnianDevonian 4West Fallsian/Sonyean372.2
Middle DevonianGivetianDevonian 3Geneseean/Taghanican/TioughnioganCazenovian382.7
EifelianSouthwoodian387.7
Early DevonianEmsianDevonian 2Sawkillian/Deer ParkianHelderbergian393.3
PragianDevonian 1407.6
Lochkovian410.8
SilurianPridoliSilurian 2419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
Sheinwoodian430.5
LlandoveryTelychianSilurian 1433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianOrdovician 5Kosovian443.8
KatianKralodvorianBohdalec †445.2
Berounian449.7 *
SandbianOrdovician 4453
Zahorany †/ViniceLetna †456.2 *
Liben †458 *
Middle OrdovicianDarriwilianOrdovician 3458.4
Dobrotivian458.5 *
Oretanian459.7 *
Sarka †461.7 *
DapingianOrdovician 2Klabava †467.3
Arenigian468
Early OrdovicianFloian470
TremadocianOrdovician 1Tremadocian477.7
CambrianFurongianStage 10Cambrian 5DatsonianMerionethDolgellian/Trempealeauan485.4
Payntonian486.8 *
Festiniogian489.2 *
JiangshanianIverian489.5
Maentwrogian493.1 *
PaibianIdamean494
MiaolingianGuzhangianCambrian 4Series 3 †MindyallanSt Davids497
Boomerangian499
DrumianUndillan500.5
Floran503
WuliuanCambrian 3Stage 5 †Templetonian504.5
Ordian507.8 *
Series 2Stage 4Caerfai509
510.8 *
Stage 3Cambrian 2514
TerreneuvianStage 2521
FortunianCambrian 1529
538.8