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
Z.-X. Qiu and Z.-D. Qiu. 1995. Chronological sequence and subdivision of Chinese Neogene mammalian faunas. Palaeogeography, Palaeoclimatology, Palaeoecology 116(1-2):41-70 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
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

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

Show less time

Show linear time

International Chronostratigraphic Timescale			North American Mammal Subages/Zones			Neogene Mammal Ages of China	Ten Million Year Bins	Cenozoic Subepochs	Obsolete Names for ICS Units			North American Land Mammal Ages
Quaternary	Holocene	Meghalayan					Cenozoic 6					Saintaugustinean	0
		Meghalayan										Santarosean	0.0004
		Northgrippian											0.0042
		Greenlandian											0.0082
	Pleistocene	Late Pleistocene	Sheridanian			Nihewanian		Late Pleistocene					0.0117
		Late Pleistocene						Late Pleistocene				Rancholabrean	0.014
		Chibanian						Middle Pleistocene				Rancholabrean	0.129
		Chibanian	Cudahyan/Sappan					Middle Pleistocene				Irvingtonian	0.21
		Calabrian	Cudahyan/Sappan					Early Pleistocene				Irvingtonian	0.774
		Calabrian	Senecan/Rexroadian									Blancan	1.4
		Gelasian											1.8
Neogene	Pliocene	Piacenzian				Yushean		Late Pliocene	Tertiary †				2.58
		Zanclean						Early Pliocene					3.6
			Late Hemphillian/late Early Hemphillian/early Early Hemphillian									Hemphillian	4.7
						Baodean							4.9
	Miocene	Messinian						Late Miocene					5.333
		Tortonian											7.246
			Late Clarendonian/Early Clarendonian									Clarendonian	9.4
						Tunggurian							11.1
		Serravallian					Cenozoic 5	Middle Miocene					11.63
		Serravallian	late Late Barstovian/early Late Barstovian/Early Barstovian									Barstovian	12.5
		Langhian				Shanwangian							13.82
		Burdigalian						Early Miocene					15.98
			Late Hemingfordian/Early Hemingfordian									Hemingfordian	16.3
			Late Hemingfordian/Early Hemingfordian			Xiejiaan						Hemingfordian	16.9
			late Late Arikareean/early Late Arikareean/late Early Arikareean/early Early Arikareean	Harrisonian								Arikareean	18.5
		Aquitanian											20.44
Paleogene	Oligocene	Chattian					Cenozoic 4	Late Oligocene					23.03
				Monroecreekian									23.1 *
				Geringian									24.7 *
		Rupelian		Geringian				Early Oligocene					27.82
												Whitneyan	29.5
												Orellan	31.8
	Eocene	Priabonian	Late Chadronian/Middle Chadronian/Early Chadronian				Cenozoic 3	Late Eocene				Chadronian	33.9
		Priabonian						Late Eocene				Duchesnean	37
		Bartonian						Middle Eocene				Duchesnean	37.71
		Bartonian	Late Uintan/Early Uintan									Uintan	39.7
		Lutetian	Late Uintan/Early Uintan				Cenozoic 2					Uintan	41.2
		Lutetian	Twinbuttean/Blacksforkian/Gardnerbuttian									Bridgerian	46.2
		Ypresian	Twinbuttean/Blacksforkian/Gardnerbuttian					Early Eocene				Bridgerian	47.8
			Lostcabinian/Lysitean/Graybullian/Sandcouleean									Wasatchian	50.5
					Cf3/Cf2/Cf1							Clarkforkian	54.9
	Paleocene	Thanetian			Cf3/Cf2/Cf1		Cenozoic 1	Late Paleocene				Clarkforkian	56
		Thanetian			Ti6/Ti5/Ti4/Ti3/Ti2/Ti1			Late Paleocene				Tiffanian	56.2
		Selandian			Ti6/Ti5/Ti4/Ti3/Ti2/Ti1			Middle Paleocene				Tiffanian	59.2
		Selandian			To3/To2/To1			Middle Paleocene				Torrejonian	60.9
		Danian			To3/To2/To1			Early Paleocene				Torrejonian	61.6
		Danian			Pu3/Pu2/Pu1			Early Paleocene				Puercan	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					Jurassic 1			199.5
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	Cambrian 4	Series 3 †	497
		Drumian	Cambrian 4		500.5
		Wuliuan	Cambrian 3		Stage 5 †	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