The Clarkforkian North American Stage, on the

geologic timescale The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochr ...

, is the North American

faunal stage In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convent ...

according to the

North American Land Mammal Ages The North American land mammal ages (NALMA) establishes a geologic timescale for North American fauna beginning during the Late Cretaceous and continuing through to the present. These periods are referred to as ages or intervals (or stages when ref ...

chronology (NALMA), typically set from 56,800,000 to 55,400,000 years BP lasting . Considered to be within the

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pala ...

, more specifically the Late Paleocene, the Clarkforkian shares its upper boundary with the

Thanetian The Thanetian is, in the ICS Geologic timescale, the latest age or uppermost stratigraphic stage of the Paleocene Epoch or Series. It spans the time between . The Thanetian is preceded by the Selandian Age and followed by the Ypresian Age ( ...

. The Clarkforkian is preceded by the

Tiffanian The Tiffanian 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 60,200,000 to 56,800,000 years BP lasting . It is usually c ...

and followed by the

Wasatchian The Wasatchian 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 55,400,000 to 50,300,000 years BP lasting . It is usually ...

NALMA stages.

Substages

It is considered to contain the following substages: *Cf3: (shares the upper boundary) and lower boundary source of the base of Clarkforkian (approximate) and upper boundary source of the base of the

Ypresian In the geologic timescale the Ypresian is the oldest age or lowest stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by the Eocene Lutetian Age. The Ypresian ...

(approximate). *Cf2: Is the lower boundary source of the base of the Clarkforkian (approximate) *Cf1: Upper boundary source of the base of the Ypresian (approximate)

Fauna

Notable mammals

Multituberculata Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the Middle Jurassic, a ...

- non-therian mammals * '' Ectypodus'', neoplagiaulacid multituberculate

Metatheria Metatheria is a mammalian clade that includes all mammals more closely related to marsupials than to placentals. First proposed by Thomas Henry Huxley in 1880, it is a more inclusive group than the marsupials; it contains all marsupials as w ...

- marsupials * ''

Peradectes ''Peradectes'' is an extinct genus of small metatherian mammals known from the CretaceousKorth, W. W. (2008). Marsupialia. In C. M. Janis, G. F. Gunnell, & M. D. Uhen (Eds.)Evolution of Tertiary Mammals of North America: Volume 2, Small Mammals, ...

'', peradectid marsupial

Carnivora Carnivora is a Clade, monophyletic order of Placentalia, placental mammals consisting of the most recent common ancestor of all felidae, cat-like and canidae, dog-like animals, and all descendants of that ancestor. Members of this group are f ...

- carnivores, including living carnivorous mammals * ''

Didymictis ''Didymictis'' ("double weasel") is an extinct genus of placental mammals from extinct subfamily Didymictinae within extinct family Viverravidae, that lived in North America and Europe from the late Paleocene to middle Eocene. Description ''Did ...

'', viverravid carnivoran Condylarthra - archaic ungulates * '' Apheliscus'', hyopsodontid condylarth * ''

Ectocion ''Ectocion'' (sometimes ''Ectocyon'') is an extinct genus of placental mammals of the family Phenacodontidae. The genus was earlier classified as ''Gidleyina'' (Simpson 1935) and ''Prosthecion'' (Patterson and West 1973). Retrieved May 2013. Pa ...

'', phenacodontid condylarth * '' Phenacodus'', phenacodontid condylarth * '' Thryptacodon'',

raccoon The raccoon ( or , ''Procyon lotor''), sometimes called the common raccoon to distinguish it from other species, is a mammal native to North America. It is the largest of the procyonid family, having a body length of , and a body weight of ...

-like arctocyonid condylarth

Creodonta Creodonta ("meat teeth") is a former order of extinct carnivorous placental mammals that lived from the early Paleocene to the late Miocene epochs in North America, Europe, Asia and Africa. Originally thought to be a single group of animals ance ...

- extinct group of carnivorous mammals * ''

Oxyaena ''Oxyaena'' ("sharp hyena") is an extinct genus of oxyaenid mammal from early Eocene of Europe, Asia and North America (most specimens being found in Colorado). Etymology The name of the genus translates as "sharp hyaena" ( and name of hyena g ...

'', semi-

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. The habitats pose nu ...

creodont Dinocerata - large, tusked herbivores * '' Probathyopsis'', early North American

uintathere Uintatheriidae is a family of extinct ungulate mammals that includes ''Uintatherium''. Uintatheres belong to the order Dinocerata, one of several extinct orders of primitive hoofed mammals that are sometimes united in the Condylarthra. Uintath ...

Eulipotyphla Eulipotyphla (, which means "truly fat and blind") is an order of mammals suggested by molecular methods of phylogenetic reconstruction, which includes the laurasiatherian members of the now-invalid polyphyletic order Lipotyphla, but not the ...

- insectivorous mammals * '' Plagioctenodon'', nyctitheriid insectivore * '' Wyonycteris'', nyctitheriid insectivore

Mesonychia Mesonychia ("middle claws") is an extinct taxon of small- to large-sized carnivorous ungulates related to artiodactyls. Mesonychids first appeared in the early Paleocene, went into a sharp decline at the end of the Eocene, and died out entirely ...

- carnivorous hoofed mammals * '' Dissacus'', dog-sized

mesonychid Mesonychia ("middle claws") is an extinct taxon of small- to large-sized carnivorous ungulates related to artiodactyls. Mesonychids first appeared in the early Paleocene, went into a sharp decline at the end of the Eocene, and died out entirely ...

Pantodonta Pantodonta is an extinct suborder (or, according to some, an order) of eutherian mammals. These herbivorous mammals were one of the first groups of large mammals to evolve (around 66 million years ago) after the end of the Cretaceous. The last ...

- large herbivorous mammals * ''

Coryphodon ''Coryphodon'' (from Greek κορῦφὴ, "point", and ὀδοὺς, "tooth", meaning ''peaked tooth'', referring to "the development of the angles of the ridges into points n the molars") is an extinct genus of pantodonts of the family Corypho ...

'', semi-aquatic,

hippo The hippopotamus ( ; : hippopotamuses or hippopotami; ''Hippopotamus amphibius''), also called the hippo, common hippopotamus, or river hippopotamus, is a large semiaquatic mammal native to sub-Saharan Africa. It is one of only two extant ...

-like pantodont * '' Titanoides'', large pantodont Primatomopha - primates and relatives * ''

Carpolestes ''Carpolestes'' ("fruit thief" from Ancient Greek κᾰρπός (karpós), “fruit, grain” + λῃστής (lēistḗs), “thief”) is a genus of extinct primate-like mammals from the late Paleocene of North America. It first existed ar ...

'', carpolestid

plesiadapiform Plesiadapiformes ("Adapid-like" or "near Adapiformes") is a group of Primates, a sister of the Dermoptera. While none of the groups normally directly assigned to this group survived, the group appears actually not to be literally extinct (in t ...

* ''

Chiromyoides ''Chiromyoides'' is a small plesiadapid primatomorph that is known for its unusually robust upper and lower incisors, deep dentary, and comparatively small cheek teeth. Species of ''Chiromyoides'' are known from the middle Tiffanian through la ...

'', small plesiadapid * '' Phenacolemur'', paromomyid plesiadapiform * ''

Plesiadapis ''Plesiadapis'' is one of the oldest known primate-like mammal genera which existed about 58–55 million years ago in North America and Europe. ''Plesiadapis'' means "near-Adapis", which is a reference to the adapiform primate of the Eocene per ...

'', plesiadapid plesiadapiform

Rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...

ia - rodents * '' Alagomys'', alagomyid rodent * ''

Paramys ''Paramys'' is an extinct genus of rodents from North America, Europe, and Asia. It is one of the oldest genera of rodents known and probably lived in trees. While the genus name literally means "near a mouse A mouse ( : mice) is a smal ...

'', ischyromyid rodent

Tillodontia Tillodontia is an extinct suborder of eutherian mammals known from the Early Paleocene to Late Eocene of China, the Late Paleocene to Middle Eocene of North America where they display their maximum species diversity, the Middle Eocene of Pakistan ...

- medium sized, digging herbivores * '' Esthonyx'', esthonychid tillodont

References

Paleocene life Paleocene animals of North America {{geochronology-stub