Obsolete Names for ICS Units

The interval definitions in this timescale are derived from the following sources:

  • 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
  • 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
  • F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 view
  • B. D. Webby. 1998. Steps toward a global standard for Ordovician stratigraphy. Newsletters in Stratigraphy 36:1-33 view

There are 55 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 92 collections

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International Chronostratigraphic TimescaleObsolete Names for ICS UnitsOrdovician of AustraliaCretaceous North American Land-Mammal AgesCambrian EpochsCarboniferous SubepochsOrdovician of the Baltic
NeogenePliocenePiacenzianTertiary †2.58
Zanclean3.6
MioceneMessinian5.333
Tortonian7.246
Serravallian11.63
Langhian13.82
Burdigalian15.98
Aquitanian20.44
PaleogeneOligoceneChattian23.03
Rupelian27.82
EocenePriabonian33.9
Bartonian37.71
Lutetian41.2
Ypresian47.8
PaleoceneThanetian56
Selandian59.2
Danian61.6
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
Bajocian168.2
Aalenian170.9
Early JurassicToarcian174.7
Pliensbachian184.2
Sinemurian192.9
Hettangian199.5
TriassicLate TriassicRhaetian201.4
Norian208.5
Carnian227
Middle TriassicLadinian237
Anisian242
Early TriassicOlenekian247.2
Induan251.2
PermianLopingianChanghsingian251.902
WuchiapingianLongtanian †254.14
GuadalupianCapitanian259.51
Wordian264.28
Roadian266.9
CisuralianKungurian273.01
Artinskian283.5
Sakmarian290.1
Asselian293.52
CarboniferousPennsylvanianGzhelianLate Pennsylvanian298.9
Kasimovian303.7
MoscovianMiddle Pennsylvanian307
BashkirianEarly Pennsylvanian315.2
MississippianSerpukhovianLate Mississippian323.2
ViseanMiddle Mississippian330.9
TournaisianEarly Mississippian346.7
DevonianLate DevonianFamennian358.9
Frasnian372.2
Middle DevonianGivetian382.7
Eifelian387.7
Early DevonianEmsian393.3
Pragian407.6
Lochkovian410.8
SilurianPridoli419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
Sheinwoodian430.5
LlandoveryTelychian433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianBolindianHarjuPorkuni443.8
KatianPirgu445.2
Eastonian449 *
Vormsi449.6 *
NabalaJohvi †450 *
ViruRakvere450.6 *
GisbornianOandu452 *
SandbianKeilaIdavere †453
Haljala453.9
Kukruse456.4 *
UhakuAluoja †457.5 *
Middle OrdovicianDarriwilianDarriwilian458.4
Lasnamagi458.9 *
Aseri460.4 *
OelandKunda462.9 *
Valaste †/Hunderum464.3 *
VolkhovLangevoja †/Vaana/Saka467.1 *
DapingianYapeenian467.3
Castlemainian468.5 *
Billingen469.3 *
Early OrdovicianFloianChewtonian470
Latorp †470.1 *
Bendigonian471.8 *
Lancefieldian473.5 *
Hunneberg473.7 *
Tremadocian477.7
Varangu481.3 *
Pakerort482.2 *
Warendian482.8 *
CambrianFurongianStage 10Late Cambrian485.4
486.3 *
486.5
Jiangshanian489.5
Paibian494
MiaolingianGuzhangianSeries 3 †Middle Cambrian497
Drumian500.5
WuliuanStage 5 †504.5
Series 2Stage 4Early Cambrian509
Stage 3514
TerreneuvianStage 2521
Fortunian529
538.8