Clarkforkian


The Clarkforkian North American Stage, on the geologic timescale, is the North American faunal stage according to the North American Land Mammal Ages chronology, 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:
  • Cf3: and lower boundary source of the base of Clarkforkian and upper boundary source of the base of the Ypresian.
  • Cf2: Is the lower boundary source of the base of the Clarkforkian
  • Cf1: Upper boundary source of the base of the Ypresian

Fauna

Notable mammals

Multituberculata - non-therian mammalsEctypodus, neoplagiaulacid multituberculate
Metatheria - marsupialsPeradectes, peradectid marsupial
Carnivora - carnivores, including living carnivorous mammalsDidymictis, viverravid carnivoran
Condylarthra - archaic ungulatesApheliscus, hyopsodontid condylarthEctocion, phenacodontid condylarthPhenacodus, phenacodontid condylarthThryptacodon, raccoon-like arctocyonid condylarth
Creodonta - extinct group of carnivorous mammalsOxyaena, semi-arboreal creodont
Dinocerata - large, tusked herbivoresProbathyopsis, early North American uintathere
Eulipotyphla - insectivorous mammalsPlagioctenodon, nyctitheriid insectivoreWyonycteris, nyctitheriid insectivore
Mesonychia - carnivorous hoofed mammalsDissacus, dog-sized mesonychid
Pantodonta - large herbivorous mammalsCoryphodon, semi-aquatic, hippo-like pantodontTitanoides, large pantodont
Primatomopha - primates and relativesCarpolestes, carpolestid plesiadapiformChiromyoides, small plesiadapidPhenacolemur, paromomyid plesiadapiformPlesiadapis, plesiadapid plesiadapiform
Rodentia - rodentsAlagomys, alagomyid rodentParamys, ischyromyid rodent
Tillodontia - medium sized, digging herbivoresEsthonyx, esthonychid tillodont