50.5 - 46.2 Ma

The definition of this interval in the timescale North American Land Mammal Ages is taken from the following source:

• 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 intervals in 7 timescales which overlap this one. show

• International Chronostratigraphic Timescale: Ypresian age, Eocene epoch, Lutetian age
• Cenozoic Subepochs: Early Eocene subepoch, Middle Eocene subepoch
• Mammal Paleogene Zones: MP 12 zone, MP 15 zone, MP 10 zone, MP 13 zone, MP 8 + 9 zone, MP 14 zone, MP 7 zone, MP 11 zone
• Paleogene Mammal Ages of Asia: Arshantan age, Sharamurunian age, Bumbanian age, Irdinmanhan age
• North American Mammal Subages/Zones: Gardnerbuttian subage, Blacksforkian subage, Twinbuttean subage
• South American Land Mammal Ages: Casamayoran age, Mustersan age
• Cretaceous-Cenozoic of New Zealand: Heretaungan age, Dannevirke epoch, Mangaorapan age

This interval is used in the definition of 710 collections

A total of 693 collections with 3750 occurrences lie within this time span