PBDB Timescale

Ammonite Chrons of North America

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

J. Palfy, P. L. Smith, and J. K. Mortensen. 2000. A U-Pb and 40Ar/39Ar time scale for the Jurassic. Canadian Journal of Earth Sciences 37(6):923-944 view
F. M. Gradstein, F. P. Agterberg, J. G. Ogg, J. Hardenbol, P. Van Veen, J. Thierry, and Z. Huang. 1995. A Triassic, Jurassic, and Cretaceous time scale. SEPM Special Publication 54 view
F. M. Gradstein, J. G. Ogg, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 view

There are 5 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 196 collections

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International Chronostratigraphic Timescale			Ammonite Chrons of North America			Mesozoic Subages		Ten Million Year Bins
Quaternary	Holocene	Meghalayan						Cenozoic 6	0
		Northgrippian							0.0042
		Greenlandian							0.0082
	Pleistocene	Late Pleistocene							0.0117
		Chibanian							0.129
		Calabrian							0.774
		Gelasian							1.8
Neogene	Pliocene	Piacenzian							2.58
	Pliocene	Zanclean							3.6
	Miocene	Messinian							5.333
		Tortonian							7.246
		Serravallian						Cenozoic 5	11.63
		Langhian							13.82
		Burdigalian							15.98
		Aquitanian							20.44
Paleogene	Oligocene	Chattian						Cenozoic 4	23.03
	Oligocene	Rupelian						Cenozoic 4	27.82
	Eocene	Priabonian						Cenozoic 3	33.9
		Bartonian						Cenozoic 3	37.71
		Lutetian						Cenozoic 2	41.2
		Ypresian						Cenozoic 2	47.8
	Paleocene	Thanetian						Cenozoic 1	56
		Selandian							59.2
		Danian							61.6
Cretaceous	Late Cretaceous	Maastrichtian				Late Maastrichtian/Early Maastrichtian		Cretaceous 8	66
		Campanian				Late Campanian/Middle Campanian/Early Campanian		Cretaceous 7	72.1
		Santonian				Late Santonian/Middle Santonian/Early Santonian		Cretaceous 6	83.6
		Coniacian				Late Coniacian/Middle Coniacian/Early Coniacian			86.3
		Turonian				Late Turonian/Middle Turonian/Early Turonian			89.8
		Cenomanian				Late Cenomanian/Middle Cenomanian/Early Cenomanian		Cretaceous 5	93.9
	Early Cretaceous	Albian				Late Albian		Cretaceous 4	100.5
						Middle Albian			106.2 *
						Early Albian			109.9 *
		Aptian				Late Aptian		Cretaceous 3	113
		Aptian				Early Aptian		Cretaceous 3	119.5 *
		Barremian				Late Barremian/Early Barremian		Cretaceous 2	121.4
		Hauterivian				Late Hauterivian/Early Hauterivian		Cretaceous 2	125.77
		Valanginian				Late Valanginian/Early Valanginian		Cretaceous 1	132.6
		Berriasian				Late Berriasian			139.8
						Middle Berriasian			140.6 *
						Early Berriasian			142.7 *
Jurassic	Late Jurassic	Tithonian				Late Tithonian	Middle Tithonian	Jurassic 6	145
		Tithonian				Early Tithonian	Middle Tithonian	Jurassic 6	146.3 *
		Kimmeridgian				Late Kimmeridgian		Jurassic 5	149.2
		Kimmeridgian				Early Kimmeridgian			152.2 *
		Oxfordian				Late Oxfordian	Middle Oxfordian/Early Oxfordian		154.8
		Oxfordian					Middle Oxfordian/Early Oxfordian		157.9 *
	Middle Jurassic	Callovian				Late Callovian/Middle Callovian/Early Callovian			161.5
		Bathonian				Late Bathonian/Middle Bathonian/Early Bathonian		Jurassic 4	165.3
		Bajocian	Epizigzagiceras			Late Bajocian			168.2
			Rotundum/Oblatum/Kirschneri/Crassicostatus/Widebayense			Late Bajocian			168.4
			Rotundum/Oblatum/Kirschneri/Crassicostatus/Widebayense			Early Bajocian			168.6 *
		Aalenian	Howelli/Scissum/Westermanni			Late Aalenian/Middle Aalenian/Early Aalenian		Jurassic 3	170.9
	Early Jurassic	Toarcian	Yakounensis/Hillebrandti/Crassicosta			Late Toarcian			174.7
			Planulata						179.3 *
					Arnioceras arnouldi				179.8 *
						Middle Toarcian			180.4 *
			Kanense						181.3 *
			Carlottense						182.3 *
			Carlottense			Early Toarcian			182.9 *
			Kunae			Early Toarcian			183.5 *
		Pliensbachian	Kunae			Late Pliensbachian/Early Pliensbachian		Jurassic 2	184.2
			Freboldi						185.1 *
			Whiteavesi/Imlayi	Tetraspidoceras					186.2 *
				Tetraspidoceras					189.2 *
			Plesechioceras harbledownense/Asteroceras varians/Coroniceras	Canadensis					190.3 *
		Sinemurian				Late Sinemurian/Early Sinemurian		Jurassic 1	192.9
			Pseudaetomoceras		Psiloceras				196.4 *
			Franziceras/Euphyllites						196.5 *
		Hettangian	Franziceras/Euphyllites			Late Hettangian/Middle Hettangian/Early Hettangian			199.5
Triassic	Late Triassic	Rhaetian						Triassic 4	201.4
		Norian				Sevatian			208.5
						Alaunian			213.2 *
						Lacian			216.7 *
		Carnian				Tuvalian		Triassic 3	227
		Carnian				Julian		Triassic 3	233.4 *
	Middle Triassic	Ladinian				Longobardian		Triassic 2	237
		Ladinian				Fassanian			239.7 *
		Anisian				Illyrian			242
						Pelsonian			243.8 *
						Bithynian			244.7 *
						Aegean			245.5 *
	Early Triassic	Olenekian				Spathian		Triassic 1	247.2
		Olenekian				Smithian			248.9 *
		Induan				Dienerian			251.2
		Induan				Griesbachian			251.4 *
Permian	Lopingian	Changhsingian						Permian 4	251.902
	Lopingian	Wuchiapingian							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	497
		Drumian					Cambrian 4	500.5
		Wuliuan					Cambrian 3	504.5
	Series 2	Stage 4					Cambrian 3	509
	Series 2	Stage 3					Cambrian 2	514
	Terreneuvian	Stage 2		521			Cambrian 2
	Terreneuvian	Fortunian		Cambrian 1			529
									538.8