North American Mammal Subages/Zones

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

  • 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. F. Steininger, W. A. Berggren, D. V. Kent, R. L. Bernor, S. Sen and J. Agusti. 1996. Circum-Mediterranean Neogene (Miocene and Pliocene) marine-continental chronologic correlations of European mammal units. The Evolution of Western Eurasian Neogene Mammal Faunas (eds. R. L. Bernor, V. Fahlbusch, and H.-W. Mittmann) 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
  • K. M. Cohen, S.C. Finney, P.L. Gibbard and J.-X. Fan. 2023. The ICS International Chronostratigraphic Chart v2023/09. view
  • F. J. Prevosti, C. O. Romano, A. M. Forasiepi, S. Hemming, R. Bonini, A. M. Candela, E. Cerdeño, M. C. Madozzo Jaén, P. E. Ortiz, F. Pujos, L. Rasia, G. I. Schmidt, M. Taglioretti, R. D. E. MacPhee, and U. F. J. Pardiñas. 2021. New radiometric 40Ar–39Ar dates and faunistic analyses refine evolutionary dynamics of Neogene vertebrate assemblages in southern South America. Scientific Reports 2021(11):9830 view
  • J. J. Flynn and C. C. Swisher, III. 1995. Cenozoic South American Land Mammal Ages: correlation to global geochronology. Geochronology Time Scales and Global Stratigraphic Correlation, SEPM Special Publication 54:317-333 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 13 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 1028 collections

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International Chronostratigraphic TimescaleNorth American Mammal Subages/ZonesTen Million Year BinsEuropean Faunal ZonesObsolete Names for ICS UnitsSouth American Land Mammal AgesNorth American Land Mammal Ages
QuaternaryHoloceneMeghalayanCenozoic 6Saintaugustinean0
Santarosean0.0004
Northgrippian0.0042
Greenlandian0.0082
PleistoceneLate PleistoceneSheridanianLujanian0.0117
Rancholabrean0.014
Chibanian0.129
Cudahyan/SappanIrvingtonian0.21
Ensenadan0.3 *
Calabrian0.774
Senecan/RexroadianBlancan1.4
SanandresianUquian †1.7 *
GelasianMN 171.8
NeogenePliocenePiacenzianMN 16Tertiary †Vorohuean2.58
Chapadmalalan2.9 *
MN 153.2
Zanclean3.6
Montehermosan3.7 *
MN 144.2
Late Hemphillian/late Early Hemphillian/early Early HemphillianHemphillian4.7
MN 13Huayquerian4.9 *
MioceneMessinian5.333
TortonianMN 127.246
MN 117.75
Chasicoan7.9 *
MN 108.7
Late Clarendonian/Early ClarendonianClarendonian9.4
MN 99.7
Mayoan9.9 *
Laventan10.9 *
MN 7 + 811.1
SerravallianCenozoic 511.63
late Late Barstovian/early Late Barstovian/Early BarstovianBarstovian12.5
MN 612.8 *
Colloncuran13.7 *
LanghianMN 513.82
Friasian15.4 *
BurdigalianMN 415.98
Santacrucian16.2 *
Late Hemingfordian/Early HemingfordianHemingfordian16.3
MN 316.9
Colhuehuapian17.4 *
late Late Arikareean/early Late Arikareean/late Early Arikareean/early Early ArikareeanHarrisonianArikareean18.5
MN 220
Aquitanian20.44
Deseadan20.9 *
MN 122.4
PaleogeneOligoceneChattianCenozoic 423.03
Monroecreekian23.1 *
Geringian24.7 *
Rupelian27.82
Tinguirirican28.9 *
Whitneyan29.5
Orellan31.8
EocenePriabonianLate Chadronian/Middle Chadronian/Early ChadronianCenozoic 3Chadronian33.9
Divisaderan35.9 *
Duchesnean37
Bartonian37.71
Late Uintan/Early UintanUintan39.7
LutetianCenozoic 241.2
Mustersan41.9 *
Twinbuttean/Blacksforkian/GardnerbuttianBridgerian46.2
Ypresian47.8
Casamayoran47.9 *
Lostcabinian/Lysitean/Graybullian/SandcouleeanWasatchian50.5
Cf3/Cf2/Cf1Clarkforkian54.9
PaleoceneThanetianCenozoic 1Riochican56
Ti6/Ti5/Ti4/Ti3/Ti2/Ti1Tiffanian56.2
Itaboraian56.9 *
Peligran58.9 *
Selandian59.2
To3/To2/To1Torrejonian60.9
Danian61.6
Tiupampan62.4 *
Pu3/Pu2/Pu1Puercan63.8
CretaceousLate CretaceousMaastrichtianCretaceous 866
CampanianCretaceous 772.1
SantonianCretaceous 683.6
Coniacian86.3
Turonian89.8
CenomanianCretaceous 593.9
Early CretaceousAlbianCretaceous 4100.5
AptianCretaceous 3113
BarremianCretaceous 2121.4
Hauterivian125.77
ValanginianCretaceous 1132.6
Berriasian139.8
JurassicLate JurassicTithonianJurassic 6145
KimmeridgianJurassic 5149.2
Oxfordian154.8
Middle JurassicCallovian161.5
BathonianJurassic 4165.3
Bajocian168.2
AalenianJurassic 3170.9
Early JurassicToarcian174.7
PliensbachianJurassic 2184.2
SinemurianJurassic 1192.9
Hettangian199.5
TriassicLate TriassicRhaetianTriassic 4201.4
Norian208.5
CarnianTriassic 3227
Middle TriassicLadinianTriassic 2237
Anisian242
Early TriassicOlenekianTriassic 1247.2
Induan251.2
PermianLopingianChanghsingianPermian 4251.902
WuchiapingianLongtanian †254.14
GuadalupianCapitanian259.51
Wordian264.28
RoadianPermian 3266.9
CisuralianKungurianPermian 2273.01
Artinskian283.5
Sakmarian290.1
AsselianPermian 1293.52
CarboniferousPennsylvanianGzhelianCarboniferous 5298.9
Kasimovian303.7
MoscovianCarboniferous 4307
Bashkirian315.2
MississippianSerpukhovianCarboniferous 3323.2
ViseanCarboniferous 2330.9
TournaisianCarboniferous 1346.7
DevonianLate DevonianFamennianDevonian 5358.9
FrasnianDevonian 4372.2
Middle DevonianGivetianDevonian 3382.7
Eifelian387.7
Early DevonianEmsianDevonian 2393.3
PragianDevonian 1407.6
Lochkovian410.8
SilurianPridoliSilurian 2419.2
LudlowLudfordian423
Gorstian425.6
WenlockHomerian427.4
Sheinwoodian430.5
LlandoveryTelychianSilurian 1433.4
Aeronian438.5
Rhuddanian440.8
OrdovicianLate OrdovicianHirnantianOrdovician 5443.8
Katian445.2
SandbianOrdovician 4453
Middle OrdovicianDarriwilianOrdovician 3458.4
DapingianOrdovician 2467.3
Early OrdovicianFloian470
TremadocianOrdovician 1477.7
CambrianFurongianStage 10Cambrian 5485.4
Jiangshanian489.5
Paibian494
MiaolingianGuzhangianCambrian 4Series 3 †497
Drumian500.5
WuliuanCambrian 3Stage 5 †504.5
Series 2Stage 4509
Stage 3Cambrian 2514
TerreneuvianStage 2521
FortunianCambrian 1529
538.8