The Clarkforkian North American Stage, on the geologic timescale, is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 56,800,000 to 55,400,000 years BP lasting. Considered to be within the Paleocene, more specifically the Late Paleocene, the Clarkforkian shares its upper boundary with the Thanetian. The Clarkforkian is preceded by the Tiffanian and followed by the Wasatchian NALMA stages.

Substages

It is considered to contain the following substages:

Fauna

Notable mammals

Multituberculata - non-therian mammals Metatheria - marsupials Carnivora - carnivores, including living carnivorous mammals Condylarthra - archaic ungulates Creodonta - extinct group of carnivorous mammals Dinocerata - large, tusked herbivores Eulipotyphla - insectivorous mammals Mesonychia - carnivorous hoofed mammals Pantodonta - large herbivorous mammals Primatomopha - primates and relatives Rodentia - rodents Tillodontia - medium sized, digging herbivores