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
- 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
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
| International Chronostratigraphic Timescale | North American Mammal Subages/Zones | Ten Million Year Bins | Obsolete Names for ICS Units | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Quaternary | Holocene | Meghalayan | Cenozoic 6 | 0 | ||||||
| Northgrippian | 0.0042 | |||||||||
| Greenlandian | 0.0082 | |||||||||
| Pleistocene | Late Pleistocene | Sheridanian | 0.0117 | |||||||
| Chibanian | 0.129 | |||||||||
| Cudahyan/Sappan | 0.21 | |||||||||
| Calabrian | 0.774 | |||||||||
| Senecan/Rexroadian | 1.4 | |||||||||
| Gelasian | 1.8 | |||||||||
| Neogene | Pliocene | Piacenzian | Tertiary † | 2.58 | ||||||
| Zanclean | 3.6 | |||||||||
| Late Hemphillian/late Early Hemphillian/early Early Hemphillian | 4.7 | |||||||||
| Miocene | Messinian | 5.333 | ||||||||
| Tortonian | 7.246 | |||||||||
| Late Clarendonian/Early Clarendonian | 9.4 | |||||||||
| Serravallian | Cenozoic 5 | 11.63 | ||||||||
| late Late Barstovian/early Late Barstovian/Early Barstovian | 12.5 | |||||||||
| Langhian | 13.82 | |||||||||
| Burdigalian | 15.98 | |||||||||
| Late Hemingfordian/Early Hemingfordian | 16.3 | |||||||||
| late Late Arikareean/early Late Arikareean/late Early Arikareean/early Early Arikareean | Harrisonian | 18.5 | ||||||||
| Aquitanian | 20.44 | |||||||||
| Paleogene | Oligocene | Chattian | Cenozoic 4 | 23.03 | ||||||
| Monroecreekian | 23.1 * | |||||||||
| Geringian | 24.7 * | |||||||||
| Rupelian | 27.82 | |||||||||
| 29.5 | ||||||||||
| Eocene | Priabonian | Late Chadronian/Middle Chadronian/Early Chadronian | Cenozoic 3 | 33.9 | ||||||
| 37 | ||||||||||
| Bartonian | 37.71 | |||||||||
| Late Uintan/Early Uintan | 39.7 | |||||||||
| Lutetian | Cenozoic 2 | 41.2 | ||||||||
| Twinbuttean/Blacksforkian/Gardnerbuttian | 46.2 | |||||||||
| Ypresian | 47.8 | |||||||||
| Lostcabinian/Lysitean/Graybullian/Sandcouleean | 50.5 | |||||||||
| Cf3/Cf2/Cf1 | 54.9 | |||||||||
| Paleocene | Thanetian | Cenozoic 1 | 56 | |||||||
| Ti6/Ti5/Ti4/Ti3/Ti2/Ti1 | 56.2 | |||||||||
| Selandian | 59.2 | |||||||||
| To3/To2/To1 | 60.9 | |||||||||
| Danian | 61.6 | |||||||||
| Pu3/Pu2/Pu1 | 63.8 | |||||||||
| Cretaceous | Late Cretaceous | Maastrichtian | Cretaceous 8 | 66 | ||||||
| Campanian | Cretaceous 7 | 72.1 | ||||||||
| Santonian | Cretaceous 6 | 83.6 | ||||||||
| Coniacian | 86.3 | |||||||||
| Turonian | 89.8 | |||||||||
| Cenomanian | Cretaceous 5 | 93.9 | ||||||||
| Early Cretaceous | Albian | Cretaceous 4 | 100.5 | |||||||
| Aptian | Cretaceous 3 | 113 | ||||||||
| Barremian | Cretaceous 2 | 121.4 | ||||||||
| Hauterivian | 125.77 | |||||||||
| Valanginian | Cretaceous 1 | 132.6 | ||||||||
| Berriasian | 139.8 | |||||||||
| Jurassic | Late Jurassic | Tithonian | Jurassic 6 | 145 | ||||||
| Kimmeridgian | Jurassic 5 | 149.2 | ||||||||
| Oxfordian | 154.8 | |||||||||
| Middle Jurassic | Callovian | 161.5 | ||||||||
| Bathonian | Jurassic 4 | 165.3 | ||||||||
| Bajocian | 168.2 | |||||||||
| Aalenian | Jurassic 3 | 170.9 | ||||||||
| Early Jurassic | Toarcian | 174.7 | ||||||||
| Pliensbachian | Jurassic 2 | 184.2 | ||||||||
| Sinemurian | Jurassic 1 | 192.9 | ||||||||
| Hettangian | 199.5 | |||||||||
| Triassic | Late Triassic | Rhaetian | Triassic 4 | 201.4 | ||||||
| Norian | 208.5 | |||||||||
| Carnian | Triassic 3 | 227 | ||||||||
| Middle Triassic | Ladinian | Triassic 2 | 237 | |||||||
| Anisian | 242 | |||||||||
| Early Triassic | Olenekian | Triassic 1 | 247.2 | |||||||
| Induan | 251.2 | |||||||||
| Permian | Lopingian | Changhsingian | Permian 4 | 251.902 | ||||||
| Wuchiapingian | Longtanian † | 254.14 | ||||||||
| Guadalupian | Capitanian | 259.51 | ||||||||
| Wordian | 264.28 | |||||||||
| Roadian | Permian 3 | 266.9 | ||||||||
| Cisuralian | Kungurian | Permian 2 | 273.01 | |||||||
| Artinskian | 283.5 | |||||||||
| Sakmarian | 290.1 | |||||||||
| Asselian | Permian 1 | 293.52 | ||||||||
| Carboniferous | Pennsylvanian | Gzhelian | Carboniferous 5 | 298.9 | ||||||
| Kasimovian | 303.7 | |||||||||
| Moscovian | Carboniferous 4 | 307 | ||||||||
| Bashkirian | 315.2 | |||||||||
| Mississippian | Serpukhovian | Carboniferous 3 | 323.2 | |||||||
| Visean | Carboniferous 2 | 330.9 | ||||||||
| Tournaisian | Carboniferous 1 | 346.7 | ||||||||
| Devonian | Late Devonian | Famennian | Devonian 5 | 358.9 | ||||||
| Frasnian | Devonian 4 | 372.2 | ||||||||
| Middle Devonian | Givetian | Devonian 3 | 382.7 | |||||||
| Eifelian | 387.7 | |||||||||
| Early Devonian | Emsian | Devonian 2 | 393.3 | |||||||
| Pragian | Devonian 1 | 407.6 | ||||||||
| Lochkovian | 410.8 | |||||||||
| Silurian | Pridoli | Silurian 2 | 419.2 | |||||||
| Ludlow | Ludfordian | 423 | ||||||||
| Gorstian | 425.6 | |||||||||
| Wenlock | Homerian | 427.4 | ||||||||
| Sheinwoodian | 430.5 | |||||||||
| Llandovery | Telychian | Silurian 1 | 433.4 | |||||||
| Aeronian | 438.5 | |||||||||
| Rhuddanian | 440.8 | |||||||||
| Ordovician | Late Ordovician | Hirnantian | Ordovician 5 | 443.8 | ||||||
| Katian | 445.2 | |||||||||
| Sandbian | Ordovician 4 | 453 | ||||||||
| Middle Ordovician | Darriwilian | Ordovician 3 | 458.4 | |||||||
| Dapingian | Ordovician 2 | 467.3 | ||||||||
| Early Ordovician | Floian | 470 | ||||||||
| Tremadocian | Ordovician 1 | 477.7 | ||||||||
| Cambrian | Furongian | Stage 10 | Cambrian 5 | 485.4 | ||||||
| Jiangshanian | 489.5 | |||||||||
| Paibian | 494 | |||||||||
| Miaolingian | Guzhangian | Cambrian 4 | Series 3 † | 497 | ||||||
| Drumian | 500.5 | |||||||||
| Wuliuan | Cambrian 3 | Stage 5 † | 504.5 | |||||||
| Series 2 | Stage 4 | 509 | ||||||||
| Stage 3 | Cambrian 2 | 514 | ||||||||
| Terreneuvian | Stage 2 | 521 | ||||||||
| Fortunian | Cambrian 1 | 529 | ||||||||
| 538.8 | ||||||||||