PBDB Timescale

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
P. L. Gibbard, M. J. Head, and M. J. C. Walker. 2010. Formal ratification of the Quaternary System/Period and the Pleistocene Series/Epoch with a base at 2.58 Ma. Journal of Quaternary Science 25(2):96-102 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. M. Gradstein, J. G. Ogg, and A. G. Smith. 2004. A Geologic Time Scale 2004 1-589 view
J. Meng and M. C. McKenna. 1998. Faunal turnovers of Paleogene mammals from the Mongolian Plateau. Nature 394:364-367 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 Timescale			North American Mammal Subages/Zones			Cenozoic Subepochs of Southern Europe	Obsolete Names for ICS Units			Cenozoic Subepochs	Ten Million Year Bins	Paleogene Mammal Ages of Asia
Quaternary	Holocene	Meghalayan									Cenozoic 6			0
		Northgrippian												0.0042
		Greenlandian												0.0082
	Pleistocene	Late Pleistocene	Sheridanian			Tarantian				Late Pleistocene				0.0117
		Chibanian	Sheridanian			Ionian				Middle Pleistocene				0.129
		Chibanian	Cudahyan/Sappan			Ionian				Middle Pleistocene				0.21
		Calabrian	Cudahyan/Sappan							Early Pleistocene				0.774
		Calabrian	Senecan/Rexroadian											1.4
		Gelasian												1.8
Neogene	Pliocene	Piacenzian					Tertiary †			Late Pliocene				2.58
		Zanclean								Early Pliocene				3.6
		Zanclean	Late Hemphillian/late Early Hemphillian/early Early Hemphillian							Early Pliocene				4.7
	Miocene	Messinian								Late Miocene				5.333
		Tortonian												7.246
		Tortonian	Late Clarendonian/Early Clarendonian											9.4
		Serravallian	Late Clarendonian/Early Clarendonian							Middle Miocene	Cenozoic 5			11.63
		Serravallian	late Late Barstovian/early Late Barstovian/Early Barstovian											12.5
		Langhian												13.82
		Burdigalian								Early Miocene				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								Late Oligocene	Cenozoic 4	Tabenbulakian	Hsandagolian	23.03
				Monroecreekian										23.1 *
				Geringian										24.7 *
		Rupelian		Geringian						Early Oligocene		Kekeamuan		27.82
		Rupelian								Early Oligocene		Kekeamuan		29.5
	Eocene	Priabonian	Late Chadronian/Middle Chadronian/Early Chadronian							Late Eocene	Cenozoic 3	Houldjinian/Ergilian/Ulangochuian		33.9
		Priabonian								Late Eocene		Houldjinian/Ergilian/Ulangochuian		37
		Bartonian								Middle Eocene		Sharamurunian/Irdinmanhan/Arshantan		37.71
		Bartonian	Late Uintan/Early Uintan											39.7
		Lutetian	Late Uintan/Early Uintan								Cenozoic 2			41.2
		Lutetian	Twinbuttean/Blacksforkian/Gardnerbuttian											46.2
		Ypresian	Twinbuttean/Blacksforkian/Gardnerbuttian							Early Eocene			Bumbanian	47.8
			Lostcabinian/Lysitean/Graybullian/Sandcouleean											50.5
					Cf3/Cf2/Cf1									54.9
	Paleocene	Thanetian			Cf3/Cf2/Cf1					Late Paleocene	Cenozoic 1	Gashatan		56
		Thanetian			Ti6/Ti5/Ti4/Ti3/Ti2/Ti1					Late Paleocene		Gashatan		56.2
		Selandian			Ti6/Ti5/Ti4/Ti3/Ti2/Ti1					Middle Paleocene				59.2
		Selandian			To3/To2/To1					Middle Paleocene				60.9
		Danian			To3/To2/To1					Early Paleocene				61.6
		Danian			Pu3/Pu2/Pu1					Early Paleocene				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									Cretaceous 2			125.77
		Valanginian									Cretaceous 1			132.6
		Berriasian									Cretaceous 1			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									Jurassic 4			168.2
		Aalenian									Jurassic 3			170.9
	Early Jurassic	Toarcian									Jurassic 3			174.7
		Pliensbachian									Jurassic 2			184.2
		Sinemurian									Jurassic 1			192.9
		Hettangian						199.5			Jurassic 1
Triassic	Late Triassic	Rhaetian						Triassic 4	201.4
		Norian						Triassic 4	208.5
		Carnian						Triassic 3	227
	Middle Triassic	Ladinian						Triassic 2	237
	Middle Triassic	Anisian						Triassic 2	242
	Early Triassic	Olenekian				Triassic 1		247.2
	Early Triassic	Induan				Triassic 1		251.2
Permian	Lopingian	Changhsingian				Permian 4		251.902
	Lopingian	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				Carboniferous 5			303.7
		Moscovian				Carboniferous 4			307
		Bashkirian				Carboniferous 4			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
	Late Devonian	Frasnian				Devonian 4			372.2
	Middle Devonian	Givetian		Devonian 3		382.7
	Middle Devonian	Eifelian		Devonian 3		387.7
	Early Devonian	Emsian		Devonian 2		393.3
		Pragian		Devonian 1		407.6
		Lochkovian		Devonian 1		410.8
Silurian	Pridoli			Silurian 2		419.2
	Ludlow	Ludfordian				423
	Ludlow	Gorstian				425.6
	Wenlock	Homerian				427.4
	Wenlock	Sheinwoodian	430.5
	Llandovery	Telychian	Silurian 1	433.4
		Aeronian		438.5
		Rhuddanian		440.8
Ordovician	Late Ordovician	Hirnantian	Ordovician 5	443.8
		Katian	Ordovician 5	445.2
		Sandbian	Ordovician 4	453
	Middle Ordovician	Darriwilian	Ordovician 3	458.4
	Middle Ordovician	Dapingian	Ordovician 2	467.3
	Early Ordovician	Floian	Ordovician 2	470
	Early Ordovician	Tremadocian	Ordovician 1	477.7
Cambrian	Furongian	Stage 10	Cambrian 5	485.4
		Jiangshanian		489.5
		Paibian		494
	Miaolingian	Guzhangian	Series 3 †	Cambrian 4	497
		Drumian		Cambrian 4	500.5
		Wuliuan		Stage 5 †	Cambrian 3	504.5
	Series 2	Stage 4			Cambrian 3	509
	Series 2	Stage 3			Cambrian 2	514
	Terreneuvian	Stage 2			Cambrian 2	521
	Terreneuvian	Fortunian			Cambrian 1	529
														538.8