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
  • 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

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.

This timescale is used in the definition of 125884 collections

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International Chronostratigraphic TimescaleNorth American Mammal Subages/Zones
18.5
PaleogeneOligoceneChattianlate Late Arikareean/early Late Arikareean/late Early Arikareean/early Early ArikareeanHarrisonian23.03
Monroecreekian23.1 *
Geringian24.7 *
Rupelian27.82
29.5
EocenePriabonianLate Chadronian/Middle Chadronian/Early Chadronian33.9
37
Bartonian37.71
Late Uintan/Early Uintan39.7
Lutetian41.2
Twinbuttean/Blacksforkian/Gardnerbuttian46.2
Ypresian47.8
Lostcabinian/Lysitean/Graybullian/Sandcouleean50.5
Cf3/Cf2/Cf154.9
PaleoceneThanetian56
Ti6/Ti5/Ti4/Ti3/Ti2/Ti156.2
Selandian59.2
To3/To2/To160.9
Danian61.6
Pu3/Pu2/Pu163.8
66