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
  • 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. Harzhauser and W. E. Piller. 2004. Integrated stratigraphy of the Sarmatian (Upper Middle Miocene) in the western Central Paratethys. Stratigraphy 1(1):65-86 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
  • F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 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
  • M. Freudenthal. 2006. Mammal Paleogene zones. personal communication view
  • F. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 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 125962 collections

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International Chronostratigraphic TimescaleNorth American Land Mammal AgesNorth American Mammal Subages/ZonesMammal Paleogene ZonesCenozoic Subepochs
18.5
PaleogeneOligoceneChattianArikareeanlate Late Arikareean/early Late Arikareean/late Early Arikareean/early Early ArikareeanHarrisonianMP 30/MP 29/MP 28/MP 27/MP 26MP 25Late Oligocene23.03
Monroecreekian23.1 *
Geringian24.7 *
RupelianMP 24/MP 23/MP 22/MP 21Early Oligocene27.82
Whitneyan29.5
Orellan31.8
EocenePriabonianChadronianLate Chadronian/Middle Chadronian/Early ChadronianMP 20/MP 19/MP 18/MP 17B/MP 17ALate Eocene33.9
Duchesnean37
BartonianMP 16Middle Eocene37.71
UintanLate Uintan/Early Uintan39.7
LutetianMP 15/MP 14/MP 13/MP 12/MP 1141.2
BridgerianTwinbuttean/Blacksforkian/Gardnerbuttian46.2
YpresianMP 10/MP 8 + 9/MP 7Early Eocene47.8
WasatchianLostcabinian/Lysitean/Graybullian/Sandcouleean50.5
ClarkforkianCf3/Cf2/Cf154.9
PaleoceneThanetianMP 6MP 1 - 5Late Paleocene56
TiffanianTi6/Ti5/Ti4/Ti3/Ti2/Ti156.2
SelandianMiddle Paleocene59.2
TorrejonianTo3/To2/To160.9
DanianEarly Paleocene61.6
PuercanPu3/Pu2/Pu163.8
66