PBDB Interval

International Chronostratigraphic Timescale

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

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, M. D. Schmitz and G. M. Ogg. 2020. Geologic Time Scale 2020 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
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
A. G. Sennikov and V. K. Golubev. 2006. Vyazniki Biotic Assemblage of the Terminal Permian. Paleontological Journal 40(suppl. 4):S475-S481 view
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
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

There are 59 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 126606 collections

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International Chronostratigraphic Timescale			Ammonite Chrons of North America			Mesozoic Subages
Jurassic	Late Jurassic	Tithonian				Late Tithonian	Middle Tithonian	145
		Tithonian				Early Tithonian	Middle Tithonian	146.3 *
		Kimmeridgian				Late Kimmeridgian		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		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		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		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		192.9
			Pseudaetomoceras		Psiloceras			196.4 *
			Franziceras/Euphyllites					196.5 *
		Hettangian	Franziceras/Euphyllites			Late Hettangian/Middle Hettangian/Early Hettangian		199.5
								201.4