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, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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
  • M. Freudenthal. 2006. Mammal Paleogene zones. personal communication 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 126689 collections

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International Chronostratigraphic TimescaleCenozoic SubepochsTen Million Year BinsNorth American Land Mammal AgesMammal Paleogene Zones
18.5
PaleogeneOligoceneChattianLate OligoceneCenozoic 4ArikareeanMP 30/MP 29/MP 28/MP 27/MP 26MP 2523.03
RupelianEarly OligoceneMP 24/MP 23/MP 22/MP 2127.82
Whitneyan29.5
Orellan31.8
EocenePriabonianLate EoceneCenozoic 3ChadronianMP 20/MP 19/MP 18/MP 17B/MP 17A33.9
Duchesnean37
BartonianMiddle EoceneMP 1637.71
Uintan39.7
LutetianCenozoic 2MP 15/MP 14/MP 13/MP 12/MP 1141.2
Bridgerian46.2
YpresianEarly EoceneMP 10/MP 8 + 9/MP 747.8
Wasatchian50.5
Clarkforkian54.9
PaleoceneThanetianLate PaleoceneCenozoic 1MP 6MP 1 - 556
Tiffanian56.2
SelandianMiddle Paleocene59.2
Torrejonian60.9
DanianEarly Paleocene61.6
Puercan63.8
66