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
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

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.

This timescale is used in the definition of 1028 collections

Show more time

Show linear time

International Chronostratigraphic Timescale			North American Mammal Subages/Zones			Cenozoic Subepochs
Quaternary	Pleistocene	Late Pleistocene	Sheridanian			Late Pleistocene	0.0117
		Chibanian	Sheridanian			Middle Pleistocene	0.129
		Chibanian	Cudahyan/Sappan			Middle Pleistocene	0.21
		Calabrian	Cudahyan/Sappan			Early Pleistocene	0.774
		Calabrian	Senecan/Rexroadian				1.4
		Gelasian					1.8
Neogene	Pliocene	Piacenzian				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	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	23.03
				Monroecreekian			23.1 *
				Geringian			24.7 *
		Rupelian		Geringian		Early Oligocene	27.82
		Rupelian				Early Oligocene	29.5
	Eocene	Priabonian	Late Chadronian/Middle Chadronian/Early Chadronian			Late Eocene	33.9
		Priabonian				Late Eocene	37
		Bartonian				Middle Eocene	37.71
		Bartonian	Late Uintan/Early Uintan				39.7
		Lutetian	Late Uintan/Early Uintan				41.2
		Lutetian	Twinbuttean/Blacksforkian/Gardnerbuttian				46.2
		Ypresian	Twinbuttean/Blacksforkian/Gardnerbuttian			Early Eocene	47.8
			Lostcabinian/Lysitean/Graybullian/Sandcouleean				50.5
					Cf3/Cf2/Cf1		54.9
	Paleocene	Thanetian			Cf3/Cf2/Cf1	Late Paleocene	56
		Thanetian			Ti6/Ti5/Ti4/Ti3/Ti2/Ti1	Late Paleocene	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
							66