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 1.4 million years.[1]
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.
It is considered to contain the following substages:
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
Original source: https://en.wikipedia.org/wiki/Clarkforkian.
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