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, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 view
  • F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 view
  • M. Freudenthal. 2006. Mammal Paleogene zones. personal communication 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
  • 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
  • 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

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 127258 collections

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International Chronostratigraphic TimescaleMammal Paleogene ZonesCenozoic SubepochsNorth American Land Mammal Ages
18.5
PaleogeneOligoceneChattianMP 30/MP 29/MP 28/MP 27/MP 26MP 25Late OligoceneArikareean23.03
RupelianMP 24/MP 23/MP 22/MP 21Early Oligocene27.82
Whitneyan29.5
Orellan31.8
EocenePriabonianMP 20/MP 19/MP 18/MP 17B/MP 17ALate EoceneChadronian33.9
Duchesnean37
BartonianMP 16Middle Eocene37.71
Uintan39.7
LutetianMP 15/MP 14/MP 13/MP 12/MP 1141.2
Bridgerian46.2
YpresianMP 10/MP 8 + 9/MP 7Early Eocene47.8
Wasatchian50.5
Clarkforkian54.9
PaleoceneThanetianMP 6MP 1 - 5Late Paleocene56
Tiffanian56.2
SelandianMiddle Paleocene59.2
Torrejonian60.9
DanianEarly Paleocene61.6
Puercan63.8
66