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
• K. M. Cohen, S.C. Finney, P.L. Gibbard and J.-X. Fan. 2023. The ICS International Chronostratigraphic Chart v2023/09. view
• M. Freudenthal. 2006. Mammal Paleogene zones. personal communication 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
• 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

• Cenozoic Subepochs
• Obsolete Names for ICS Units
• Ten Million Year Bins
• European Faunal Units
• European Faunal Zones
• Mammal Paleogene Zones
• Cenozoic Subepochs of Southern Europe
• Central Paratethys Stages
• Neogene Mammal Ages of China
• Paleogene Mammal Ages of Asia
• North American Land Mammal Ages
• South American Land Mammal Ages
• Cretaceous-Cenozoic of New Zealand

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