Fort Union Formation

Geologic formation in the northwestern United States

Fort Union Formation

Stratigraphic range: Maastrichtian-Selandian (Lancian-Clarkforkian)
~66–58 Ma

PreꞒ

Fossils from the Fort Union Formation

Type| Geological formation
Sub-units| Atwell Gulch, China Butte, Ekalaka, Lebo, lower Ludlow, Overland, Rock Bench Quarry, Sentinel Butte, Shotgun, Somber beds, Tongue River, Tullock, upper Ludlow, Polecat Bench Formation
Underlies| Wasatch Formation
Overlies| Hell Creek Formation, Lance Formation
Lithology
Primary| Sandstone, shale
Other| Coal
Location
Coordinates| 47°00′N 104°36′W﻿ / ﻿47.0°N 104.6°W﻿ / 47.0; -104.6
Approximate paleocoordinates| 52°48′N 80°06′W﻿ / ﻿52.8°N 80.1°W﻿ / 52.8; -80.1
Region| Montana, North Dakota
Wyoming, Colorado
Country|  United States
Extent| Powder River Basin
Fort Union Formation - stratigraphy

The Fort Union Formation is a geologic unit containing sandstones, shales, and coal beds in Wyoming, Montana, and parts of adjacent states. In the Powder River Basin, it contains important economic deposits of coal, uranium, and coalbed methane.[1]

## Description

[edit]

The Fort Union is mostly of Paleocene age and represents a time of extensive swamps as well as fluvial and lacustrine conditions. The rocks are more sandy in southwestern Wyoming and more coal-bearing in northeast Wyoming and southeast Montana, reflecting a general change from rivers and lakes in the west to swamps in the east, but all three environments were present at various times in most locations.[2]

Coal in the Fort Union in the Powder River Basin occurs mainly in the Tongue River Member, where as many as 32 coal seams total more than 300 feet in thickness.[1] One such bed, the Wyodak Coal near Gillette, Wyoming, is as much as 110 feet (34 m) thick. Most of the coals in the Fort Union Formation are ranked subbituminous.[3]

## Fossil content

[edit]

|  |

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Color key
| Taxon | Reclassified taxon | Taxon falsely reported as present | Dubious taxon or junior synonym | Ichnotaxon | Ootaxon | Morphotaxon

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| Notes
Uncertain or tentative taxa are in small text; ~~crossed out~~ taxa are discredited.

### Mammals

[edit]

#### Cimolestans

[edit]

Cimolestans reported from the Fort Union Formation

Genus | Species | Locality  | Stratigraphic member | Material | Notes | Images
Crustulus | C. fontanus | Northeastern Montana.[4] | Tullock Member.[4] | An isolated upper molar.[4] | A pantodont.  |

#### Leptictids

[edit]

Leptictids reported from the Fort Union Formation

Genus | Species | Locality  | Stratigraphic member | Material | Notes | Images
Prodiacodon | P. crustulum | Garfield & McCone counties, Montana.[5] | Tullock Member.[5] | Fragmentary dentary & isolated teeth.[5] | A leptictid.  |

#### Marsupials

[edit]

Marsupials reported from the Fort Union Formation

Genus | Species | Locality  | Stratigraphic member | Material | Notes | Images
Peradectes | P. sp.  | Swain Quarry, Wyoming.[6] |  | Upper & lower molars.[6] | Reassigned to Swaindelphys.  |
Swaindelphys | S. cifellii | Swain Quarry, Wyoming.[6] |  | Upper & lower molars.[6] | An opossum.  |

#### Primatomorphs

[edit]

Primatomorphs reported from the Fort Union Formation

Genus | Species | Locality  | Stratigraphic member | Material | Notes | Images
Carpodaptes | C. sp.  | Wind River Basin, Wyoming.[7] | Shotgun Member.[7] | 2 isolated fourth lower premolars.[7] | A carpolestid.  |
Chiromyoides | C. caesor | Hell's Half Acre (UCM locality 78009), Mesa County, Colorado.[8] |  | A single upper incisor (UCM 53515).[8] | A plesiadapid.  |
C. gigas | Piceance Creek Basin, Colorado.[8] |  | Multiple teeth.[8] | A plesiadapid.  |
C. sp.  | UCM locality 78060, Colorado.[8] |  | A left molar (UCM 41606).[8] | A plesiadapid.  |
Elphidotarsius | E. shotgunensis | Wind River Basin, Wyoming.[7] | Shotgun Member.[7] | Right ramus of mandible & isolated teeth.[7] | A carpolestid.  |
Nannodectes | N. gazini | Fremont County, Colorado.[8] |  | A right maxilla (USGS 16872).[8] | A plesiadapid.  |
Palaechthon | P., near P. alticuspis | Wind River Basin, Wyoming.[7] | Shotgun Member.[7] | 3 upper molars & 4 lower molars.[7] | A plesiadapiform.  |
P. woodi | Wind River Basin, Wyoming.[7] | Shotgun Member.[7] | A lower jaw & 13 isolated teeth.[7] | A plesiadapiform.  |
Palenochtha | P. cf. minor | Wind River Basin, Wyoming.[7] | Shotgun Member.[7] | 5 lower teeth.[7] | A plesiadapiform.  |
Paromomys | P., near P. depressidens | Wind River Basin, Wyoming.[7] | Shotgun Member.[7] | Approximately 12 upper teeth, 8 isolated lower teeth & a jaw fragment.[7] | A paromomyid.  |
Phenacolemur | P. fremontensis | Wind River Basin, Wyoming.[7] | Shotgun Member.[7] | A lower jaw & isolated teeth.[7] | A paromomyid.  |
P. cf. frugivorus | Wind River Basin, Wyoming.[7] | Shotgun Member.[7] | 2 upper molars & 8 isolated lower molars.[7] | A paromomyid.  |
Plesiadapis | P. dubius | Piceance Creek Basin, Colorado.[8] |  | Jaw elements & teeth.[8] | A plesiadapid.  |
P. fodinatus | Piceance Creek Basin, Colorado.[8] |  | Jaw elements & teeth.[8] | A plesiadapid.  |
P. sp.  | Wind River Basin, Wyoming.[7] | Shotgun Member.[7] | 5 lower molars, 3 anterior upper molars & a premolar.[7] | A plesiadapid.  |
Plesiolestes | P. cf. problematicus | Wind River Basin, Wyoming.[7] | Shotgun Member.[7] | Approximately 45 isolated teeth.[7] | A plesiadapiform.  |
Pronothodectes | P. intermedius | Wind River Basin, Wyoming.[7] | Shotgun Member.[7] | Jaw elements & teeth.[7] | A plesiadapid.  |
Purgatorius | P. janisae | 'Harley's Point’ UCMP locality V77087, Garfield County, Montana.[9] | Tullock Member.[9] | UCMP 150018 (right m1), and UCMP 192398 (left m3).[9] | A purgatoriid.  |
P. mckeeveri | Garfield County, Montana.[9] | Tullock Member.[9] | Dentary remains & teeth.[9] | A purgatoriid.  |
P. cf. P. mckeeveri | Harley's Point’ UCMP locality V77087, Garfield County, Montana.[9] | Tullock Member.[9] | UCMP 150019 (right M2), and UCMP 150020 (right M2).[9] | A purgatoriid.  |
Torrejonia | Cf. T. wilsoni | Wind River Basin, Wyoming.[7] | Shotgun Member.[7] | About 14 lower teeth & possibly 3 upper molars.[7] | A plesiadapiform.  |
Zanycteris | Z. honeyi | UMC locality number 92177, Colorado.[10] | Atwell Gulch Member.[10] | Right maxilla (UCM 87378).[10] | A plesiadapiform.  |

#### Ungulates

[edit]

Ungulates reported from the Fort Union Formation

Genus | Species | Locality  | Stratigraphic member | Material | Notes | Images
Dissacus | D. argenteus | Princeton Quarry, Park County, Wyoming.[11] | Upper part of the formation.[11] | Jaw elements & teeth.[11] | A mesonychid.  |
D. cf. navajovius | Princeton Quarry, Park County, Wyoming.[11] | Upper part of the formation.[11] | Jaw elements & teeth.[11] | Specimens reassigned to D. argenteus.  |
D. praenuntius | Park County, Wyoming.[11] | Upper part of the formation.[11] | Mandible (YPM-PU 16159).[11] | A mesonychid also known from the Willwood Formation.  |
Ectocion | E. mediotuber | Princeton Quarry, Wyoming.[12] |  | Dentary.[12] | A phenacodontid.  |
Periptychus | P. carinidens | Makoshika State Park, Montana.[13] |  |  | A periptychid also found in the Nacimiento, North Horn, Black Peaks & Animas formations.  |
Sigynorum | S. magnadivisus | Great Divide Basin, southern Wyoming.[14] | China Butte Member.[14] |  | An arctocyonid.  |

### Reptiles

[edit]

#### Birds

[edit]

A partial ornithurine coracoid bone found in this formation is identical to others found in the older Hell Creek Formation. At present, this unnamed species is the only known individual bird species that have survived the Cretaceous–Paleogene extinction event.[15]

Birds reported from the Fort Union Formation

Genus | Species | Locality  | Stratigraphic member | Material | Notes | Images
Lithornis | L. celetius | Bangtail Quarry, Sedan Quadrangle, Park County, Montana.[16] |  |  | A lithornithid.  |

#### Crocodilians

[edit]

Crocodilians reported from the Fort Union Formation

Genus | Species | Location  | Stratigraphic member | Material | Notes | Images
Allognathosuchus | A. sp.  | Princeton Quarry, Park County, Wyoming.[17] |  | Anterior end of left dentary (PU 16988).[17] | A crocodilian.  |

#### Squamates

[edit]

Squamates reported from the Fort Union Formation

Genus | Species | Locality  | Stratigraphic member | Material | Notes | Images
Anguidae | Genus & species indeterminate  | Swain Quarry, Carbon County, Wyoming.[18] |  | Fragmentary jaw elements.[18] | An anguid lizard.  |
cf. Anguidae |  | Swain Quarry, Carbon County, Wyoming.[18] |  | 6 partial dentaries.[18] | Provisionally referred to anguid lizards based on size & shape.  |
Contogenys | cf. C. sloani | Swain Quarry, Carbon County, Wyoming.[18] |  | Posterior part of a right maxilla (AMNH 12069).[18] | A skink.  |
Exostinus | E. cf. E. lancensis | Swain Quarry, Carbon County, Wyoming.[18] |  | 4 partial dentaries.[18] | A xenosaurid lizard.  |
E. rugosus | Princeton & Schaff quarries, Park County, Wyoming.[17] |  | Multiple specimens.[17] | A xenosaurid lizard.  |
Glyptosaurinae | Genus & species indeterminate  | Swain Quarry, Carbon County, Wyoming.[18] |  | Several jaw remains.[18] | A glyptosaurine lizard.  |
Glyptosaurinae or Odaxosaurinae | Genus & species indeterminate  | Swain Quarry, Carbon County, Wyoming.[18] |  | Fragmentary jaw elements & osteoderms.[18] | Indeterminate lizard remains.  |
Machaerosaurus | M. torrejonensis | Swain Quarry, Carbon County, Wyoming.[18] |  | Numerous jaw elements.[18] | An anguid lizard also known from the Nacimiento Formation.  |
Odaxosaurus | O. piger | Swain Quarry, Carbon County, Wyoming.[18] |  | Many fragmentary jaw remains.[18] | An anguid lizard.  |
Oligodontosaurus | O. wyomingensis | Park County, Wyoming.[17] |  | A left mandible (PU 14246).[17] | An amphisbaenian.  |
Palaeosaniwa | cf. P. canadensis | Swain Quarry, Carbon County, Wyoming.[18] |  | Medial part of left dentary (AMNH 15957).[18] | A large anguimorph lizard.  |
Palaeoxantusia | P. fera | Swain Quarry, Carbon County, Wyoming.[18] |  | Numerous jaw elements.[18] | A night lizard.  |
Pancelosaurus | P. piger | Princeton, Fritz & Schaff quarries, Park County, Wyoming.[17] |  | Multiple skull elements.[17] | An anguid lizard.  |
Provaranosaurus | P. acutus | Princeton Quarry, Park County, Wyoming.[17] |  | PU 14243 (left maxilla), 14561 (anterior portion of left dentary) & 17145 ( fragment of left maxilla).[17] | A palaeovaranid lizard.  |
cf. P. sp.  | Swain Quarry, Carbon County, Wyoming.[18] |  | 3 partial dentaries (AMNH 14306, 14307 & 14309).[18] | A palaeovaranid lizard.  |
Rhineuridae | Unidentified genus & species  | Fritz Quarry, Park County, Wyoming.[17] |  | An almost complete right dentary & a broken vertebra (PU 18627).[17] | An amphisbaenian.  |
Saniwa | cf. S. sp.  | Swain Quarry, Carbon County, Wyoming.[18] |  | 2 trunk vertebrae (AMNH 15960 & 16003).[18] | A varanid.  |
Swainiguanoides | S. milleri | Swain Quarry, Carbon County, Wyoming.[18] |  | Jaw elements.[18] | An iguanid.  |

#### Testudines

[edit]

Testudines reported from the Fort Union Formation

Genus | Species | Locality  | Stratigraphic member | Material | Notes | Images
Atoposemys | A. entopteros | Montana.[19] | Tullock Member.[19] |  | A softshell turtle.  |
Axestemys | A. montinsana | PTRM Site V02017, Slope County, North Dakota.[20] |  | Numerous skull, limb & shell fragments.[20] | A softshell turtle also found in the Melville & Denver formations.  |
Cardiochelyon | C. rogerwoodi | Reis Quarry, Park County, Wyoming.[21] |  | Partial skeleton (YPM PU14671).[21] | A kinosternoid formerly thought to be a platysternid.  |
Cedrobaena | C. putorius | Cedar Point Quarry, Wyoming.[22] |  | Shell & skull elements.[22] | A baenid turtle also found in the Hell Creek Formation.  |
Hutchemys | H. arctochelys | Burns Mine, Washoe Area, Carbon County, Montana.[23] | Tongue River Member.[23] | Multiple shell elements.[23] | A softshell turtle.  |
H. rememdium | Fallon County, Montana.[23] | Ekalaka Member.[23] | A near complete postcranial skeleton (YPM PU 16795) & shell elements.[23] | A softshell turtle.  |
H. sp.  | Duffy's Ranch, Sweet Grass County, Montana.[23] |  | YPM PU 11566.[23] | A softshell turtle.  |
Ptychogaster | P. sp.  | Princeton Quarry & Reiss Locality, Park County, Wyoming.[17] |  | PU 17794 (fragments of the skull & shell), 14671 & 16443 (shells).[17] | A turtle.  |
Tullochelys | T. montanus | Montana.[19] | Tullock Member.[19] |  | A chelydrid turtle also known from the Hell Creek Formation.  |

### Amphibians

[edit]

Amphibians reported from the Fort Union Formation

Genus | Species | Locality  | Stratigraphic member | Material | Notes | Images
Amphiuma | A. jepseni | Park County, Wyoming.[17] |  | PU 14666 (partial vertebral column), 14668 (partial skull) & 16788 (dislocated vertebrae).[17] | An aquatic salamander.  |
Anura | Incertae sedis | Park County, Wyoming.[17] |  | PU 14662 (distal end of right radioulna), 14663 (proximal end of left radioulna), 14669 (phalanx), 13372 (right maxilla).[17] | A frog.  |
Discoglossidae | Undescribed genus & species  | Park County, Wyoming.[17] |  | Distal end of right humerus (PU 14670).[17] | A frog similar to undescribed discoglossid remains from the Hell Creek Formation.[17] |
Eorhinophrynus | E. sp.  | Princeton & Fritz quarries, Park County, Wyoming.[17] |  | Humeri & vertebrae.[17] | A burrowing toad.  |
Opisthotriton | O. kayi | Princeton Quarry, Park County, Wyoming.[17] |  | Multiple specimens.[17] | A salamander.  |
Scapherpeton | S. tectum | Princeton & Schaff quarries, Park County, Wyoming.[17] |  | PU 20583 (3 broken vertebrae, an atlas, an ilium & a rib) & PU 19500 (a humerus).[17] | A salamander.  |

### Fish

[edit]

Fish reported from the Fort Union Formation

Genus | Species | Locality  | Stratigraphic member | Material | Notes | Images
Acipenseridae | Morphotype A  | Eagle Mine near Bear Creek, Carbon County, Montana.[24] |  | A complete lateral scute (YPM VPPU 17066).[24] | A large sturgeon.  |
Morphotype B  | Highway Blowout Site, Fallon County, Montana.[24] | Tongue River Member.[24] | A complete lateral scute (YPM VPPU 16646).[24] | A large sturgeon.  |
Amia | A. basiloides | Burns Mine and Eagle Mine near Bear Creek, Carbon County, Montana[25] |  | A near complete skull and partial skeleton, isolated vertebra[25] | A large bowfin.  |
Atractosteus | A. grandei | Bowman County, North Dakota.[26] | Lowest Danian strata.[26] |  | A large gar.  |
Cyclurus | C. fragosus | Schaff Quarry, Park County, Wyoming.[17] |  | 3 vertebral centra (PU 21174).[17] | A bowfin.  |
Engdahlichthys | E. milviaegis | Montana.[27] | Tullock Member.[27] |  | A fairly small sturgeon.  |
Polyodon | P. tuberculata | Montana.[27] | Tullock Member.[27] | 3 specimens.[27] | A paddlefish.  |

### Invertebrates

[edit]

#### Bivalves

[edit]

Bivalves reported from the Fort Union Formation

Genus | Species | Locality  | Stratigraphic member | Material | Notes | Images
Pisidium | P. sp. indet.  | Powder River Basin.[28] | Tongue River Member.[28] | 8 specimens.[28] | A sphaeriid.  |
P.? sp. indet.  | Powder River Basin.[28] | Tongue River Member.[28] | 3 specimens.[28] | A sphaeriid.  |
Plesielliptio | P. priscus | Powder River Basin.[28] | Tongue River Member.[28] | Numerous specimens.[28] | A unionid.  |
cf. P. priscus | Powder River Basin.[28] | Tongue River Member.[28] | Several specimens.[28] | A unionid.  |
P. silberlingi | Powder River Basin.[28] | Tongue River Member.[28] | Numerous specimens.[28] | A unionid.  |
cf. P. silberlingi | Powder River Basin.[28] | Tongue River Member.[28] | 6 specimens.[28] | A unionid.  |
P. sp. indet.  | Powder River Basin.[28] | Tongue River Member.[28] | 2 specimens.[28] | A unionid.  |
Sphaeriidae | Gen. & sp. indet.  | Powder River Basin.[28] | Tongue River Member.[28] | Numerous specimens.[28] | A sphaeriid.  |
Sphaerium | S. sp. indet.  | Powder River Basin.[28] | Tongue River Member.[28] | 1 specimen.[28] | A sphaeriid.  |
S.? sp. indet.  | Powder River Basin.[28] | Tongue River Member.[28] | Several specimens.[28] | A sphaeriid.  |
Unionidae | Gen. & sp. indet.  | Powder River Basin.[28] | Tongue River Member.[28] | 11 specimens.[28] | A unionid.  |

#### Gastropods

[edit]

Gastropods reported from the Fort Union Formation

Genus | Species | Locality  | Stratigraphic member | Material | Notes | Images
Acroloxus | A.? minutus | Powder River Basin.[28] | Tongue River Member.[28] | 2 specimens.[28] | A river limpet.  |
A. sp. indet.  | Powder River Basin.[28] | Tongue River Member.[28] | 1 specimen.[28] | A river limpet.  |
Clenchiella | C. n. sp. A  | Powder River Basin.[28] | Tongue River Member.[28] | Numerous specimens.[28] | A clenchiellid.  |
C. n. sp. A?  | Powder River Basin.[28] | Tongue River Member.[28] | 1 specimen.[28] | A clenchiellid.  |
C. cf. C. n. sp. A  | Powder River Basin.[28] | Tongue River Member.[28] | 10 specimens.[28] | A clenchiellid.  |
C. sp. indet.  | Powder River Basin.[28] | Tongue River Member.[28] | 30 specimens.[28] | A clenchiellid.  |
Hydrobia | H. anthonyi | Powder River Basin.[28] | Tongue River Member.[28] | 2 specimens.[28] | A hydrobiid.  |
H. sp. A  | Powder River Basin.[28] | Tongue River Member.[28] | Numerous specimens.[28] | A hydrobiid.  |
H. cf. H. sp. A  | Powder River Basin.[28] | Tongue River Member.[28] | 2 specimens.[28] | A hydrobiid.  |
H. sp. B?  | Powder River Basin.[28] | Tongue River Member.[28] | Multiple specimens.[28] | A hydrobiid.  |
H. sp. C?  | Powder River Basin.[28] | Tongue River Member.[28] | 1 specimen.[28] | A hydrobiid.  |
H. sp. indet.  | Powder River Basin.[28] | Tongue River Member.[28] | Multiple specimens.[28] | A hydrobiid.  |
H.? sp. indet.  | Powder River Basin.[28] | Tongue River Member.[28] | 2 specimens.[28] | A hydrobiid.  |
Lioplacodes | L. multistriata | Powder River Basin.[28] | Tongue River Member.[28] | Numerous specimens.[28] | A viviparid.  |
L. tenuicarinata | Powder River Basin.[28] | Tongue River Member.[28] | Numerous specimens.[28] | A viviparid.  |
L. tenuicarinata? | Powder River Basin.[28] | Tongue River Member.[28] | 11 specimens.[28] | A viviparid.  |
L. limneaformis | Powder River Basin.[28] | Tongue River Member.[28] | Numerous specimens.[28] | A viviparid.  |
L. sp. indet.  | Powder River Basin.[28] | Tongue River Member.[28] | Numerous specimens.[28] | A viviparid.  |
L.? sp. indet.  | Powder River Basin.[28] | Tongue River Member.[28] | 1 specimen.[28] | A viviparid.  |
Valvata? | V.? sp. indet.  | Powder River Basin.[28] | Tongue River Member.[28] | 1 specimen.[28] | A valvatid.  |
Viviparus | V. raynoldsanus | Powder River Basin.[28] | Tongue River Member.[28] | Numerous specimens.[28] | A viviparid.  |
V. raynoldsanus? | Powder River Basin.[28] | Tongue River Member.[28] | 1 specimen.[28] | A viviparid.  |
V. cf. V. raynoldsanus | Powder River Basin.[28] | Tongue River Member.[28] | 17 specimens.[28] | A viviparid.  |
V. sp.  | Powder River Basin.[28] | Tongue River Member.[28] | Multiple specimens.[28] | A viviparid.  |

### Plants

[edit]

Plants reported from the Fort Union Formation

Genus | Species | Locality  | Stratigraphic member | Material | Notes | Images
Aesculus | A. hickeyi | Custer National Forest, Powder River County, Montana.[29] | Tongue River Member.[29] | Leaves.[29] | A horse chestnut.  |
Amersinia | A. obtrullata | Custer National Forest, Powder River County, Montana.[29] | Tongue River Member.[29] | Fruits.[29] | A nyssaceaen, may be produced by the same plant as Beringiaphyllum cupanioides.  |
Beringiaphyllum | B. cupanioides | Custer National Forest, Powder River County, Montana.[29] | Tongue River Member.[29] | Leaf (UF 18969-60464).[29] | A nyssaceaen, may be produced by the same plant as Amersinia obtrullata.  |
Browniea | B. serrata | Mexican Hat locality & Custer National Forest, Powder River County, Montana.[29][30] | Lebo Member & Tongue River Member.[29][30] | Leaves showing signs of insect damage.[30] | A nyssaceaen.  |
Cercidiphyllum | C. genetrix | Mexican Hat locality, Montana.[30] | Lebo Member.[30] | Leaves showing signs of insect damage.[30] | A katsura tree.  |
Cornus | C. swingii | Custer National Forest, Powder River County, Montana.[29] | Tongue River Member.[29] | Leaves.[29] | A dogwood.  |
Davidia | D. antiqua | Custer National Forest, Powder River County, Montana.[29] | Tongue River Member.[29] | Leaves & fruits.[29] | A dove tree.  |
Cf. Dennstaedtia | Cf. D. americana | Custer National Forest, Powder River County, Montana.[29] | Tongue River Member.[29] | A single specimen of sterile foliage (UF 18969-34532).[29] | A fern.  |
Dicotylophyllum | D. hansonium | Williston Basin, North Dakota.[31] | Tongue River Member.[31] | Leaves.[31] | A dicot.  |
D. horsecreekium | Williston Basin, North Dakota.[31] | Ludlow Member.[31] | Leaves.[31] | A dicot.  |
Eostangeria | E. pseudopteris | Sweetwater County, Wyoming.[32] | Upper part of the formation.[32] | Multiple specimens.[32] | A cycad.  |
Equisetum | E. sp.  | Custer National Forest, Powder River County, Montana.[29] | Tongue River Member.[29] | A single stem (UF 18969-60476A).[29] | A horsetail.  |
"Ficus" | "F." artocarpoides | Mexican Hat locality.[30] | Lebo Member.[30] | Leaves with signs of hole feeding and insect mining.[30] | A fig-tree.  |
Glyptostrobus | G. europaeus | Mexican Hat locality.[30] | Lebo Member.[30] | Leafy branches.[30] | A conifer.  |
Juglandiphyllites | J. glabra | Mexican Hat locality, Montana.[30] | Lebo Member.[30] | Leaves with insect damage and probable lepidopteran leaf mines.[30] | A member of the walnut family.  |
Lauraceae | Species 1  | Mexican Hat locality, Montana.[30] | Lebo Member.[30] | Leaf with piercing and sucking marks from insects.[30] |  |
Species 2  | Mexican Hat locality, Montana.[30] | Lebo Member.[30] | Leaves showing signs of insect damage.[30] |  |
Macginistemon | M. mikanoides | Custer National Forest, Powder River County, Montana.[29] | Tongue River Member.[29] | Stamen groups.[29] | A platanaceaen.  |
Macginitiea | M. gracilis | Custer National Forest, Powder River County, Montana.[29] | Tongue River Member.[29] | A fragmentary leaf (UF 18969-38380).[29] | A platanaceaen.  |
M. nascens | Williston Basin, North Dakota.[31] | Ludlow Member.[31] | Leaves.[31] | A platanaceaen.  |
Meliosma | M. thriviensis | Williston Basin, North Dakota.[31] | Ludlow Member.[31] | Leaves.[31] | A sabiaceaen.  |
M. vandaelium | Williston Basin, North Dakota.[31] | Tongue River Member.[31] | Multiple leaves.[31] | A sabiaceaen.  |
Nordenskioeldia | N. borealis | Custer National Forest, Powder River County, Montana.[29] | Tongue River Member.[29] | Fruit.[29] | A trochodendrale.  |
Paleonelumbo | P. macroloba | Mexican Hat locality, Montana.[30] | Lebo Member.[30] | Leaves.[30] | A nelumbonaceaen.  |
Paranymphaea | P. crassifolia | Mexican Hat locality, Montana.[30] | Lebo Member.[30] | Leaves.[30] | A nymphaeaceaen.  |
Phyllites | P. demoresii | Custer National Forest, Powder River County, Montana.[29] | Tongue River Member.[29] | Leaves.[29] |  |
Platanus | P. raynoldsii | Mexican Hat locality, Montana.[30] | Lebo Member.[30] | Leaves showing signs of insect damage.[30] | A plane-tree.  |
P. sp.  | Custer National Forest, Powder River County, Montana.[29] | Tongue River Member.[29] | Leaves.[29] | A plane-tree.  |
Polyptera | P. manningii | Mexican Hat locality, Montana.[30] | Lebo Member.[30] | Fruits.[30] | A member of the walnut family.  |
"Populus" | "P". nebrascensis | Mexican Hat locality, Montana.[30] | Lebo Member.[30] | Leaves showing signs of insect damage.[30] | A poplar.  |
Porosia | P. verrucosa | Custer National Forest, Powder River County, Montana.[29] | Tongue River Member.[29] | Fruits.[29] | A rutaceaen.  |
Taxodium | T. olrikii | Custer National Forest, Powder River County, Montana.[29] | Tongue River Member.[29] | [29] | A cypress tree.  |
Ternstromites | cf. T. aureavallis | Mexican Hat locality, Montana.[30] | Lebo Member.[30] | Leaf with a gall at the intersection of primary and secondary veins.[30] | A theaceaen.  |
T. paucimissouriensis | Williston Basin, North Dakota.[31] | Ludlow & Tongue River Members.[31] | Leaves.[31] | A theaceaen.  |
Trochodendroides | T. genetrix | Custer National Forest, Powder River County, Montana.[29] | Tongue River Member.[29] | A few leaves.[29] | A saxifrage.  |
Ulmites | U. microphylla | Custer National Forest, Powder River County, Montana.[29] | Tongue River Member.[29] | Leaves.[29] | An ulmaceaen.  |
Zizyphoides | Z. flabella | Mexican Hat locality, Montana & Custer National Forest, Powder River County, Montana.[30][29] | Lebo Member & Tongue River Member.[30][29] | Leaves showing signs of insect damage.[30] | A trochodendrale.  |

## See also

[edit]

* List of fossiliferous stratigraphic units in Colorado
* List of fossiliferous stratigraphic units in Montana
* List of fossiliferous stratigraphic units in North Dakota
* List of fossiliferous stratigraphic units in Wyoming
* Uranium mining in Wyoming
* Guaduas Formation, contemporaneous coal-bearing formation of northern South America

## References

[edit]

1. ^ a b Wyodak Coal, Tongue River Member of the Fort Union Formation, Powder River Basin, Wyoming: "No-Coal Zones" and Their Effects on Coalbed Methane Production, by Mark Ashley, 2005
2. ^ Eocene and Paleocene rocks of the southern and central basins, by Robert E. McDonald, in Geologic Atlas of the Rocky Mountain Region, Rocky Mountain Association of Geologists, Denver, CO, 1972: p. 248
3. ^ Cretaceous and Tertiary coals of the Rocky Mountains and Great Plains regions, by R.M. Flores and T.A. Cross, 1991, in Economic Geology, U.S., Geological Society of America, Decade of North American Geology Series, vol. P-2, p. 547-571.
4. ^ a b c Clemens, William A. (2018-02-17). "A pantodont (Mammalia) from the latest Puercan North American Land Mammal Age (earliest Paleocene) of the Western Interior, USA". Historical Biology. 30 (1–2): 183–188\. Bibcode:2018HBio...30..183C. doi:10.1080/08912963.2016.1276178. ISSN 0891-2963. S2CID 132830375.1–2&rft.pages=183-188&rft.date=2018-02-17&rft_id=info:doi/10.1080/08912963.2016.1276178&rft_id=https://api.semanticscholar.org/CorpusID:132830375#id-name=S2CID&rft.issn=0891-2963&rft_id=info:bibcode/2018HBio...30..183C&rft.aulast=Clemens&rft.aufirst=William+A.&rft_id=https://doi.org/10.1080/08912963.2016.1276178&rfr_id=info:sid/en.wikipedia.org:Fort+Union+Formation" class="Z3988">
5. ^ a b c Clemens, W. (January 9, 2015). "(Leptictidae, Mammalia) from the Tullock Member of the Fort Union Formation, Garfield and McCone Counties, Montana, USA". PaleoBios. 32 (1): 1–17\. doi:10.5070/P9321025382. S2CID 55974838.
6. ^ a b c d Johanson, Zerina (November 1996). "New marsupial from the Fort Union Formation, Swain Quarry, Wyoming". Journal of Paleontology. 70 (6): 1023–1031\. Bibcode:1996JPal...70.1023J. doi:10.1017/S0022336000038725. ISSN 0022-3360. S2CID 133554548.
7. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj Gazin, C. Lewis (1971). "Paleocene primates from the shotgun member of the Fort Union Formation in the Wind River Basin, Wyoming". Proceedings of the Biological Society of Washington. 84: 13–37\. ISSN 0006-324X.
8. ^ a b c d e f g h i j k l Burger, Benjamin J.; Honey, James G. (2008-09-12). "Plesiadapidae (Mammalia, Primates) from the late Paleocene Fort Union Formation of the Piceance Creek Basin, Colorado". Journal of Vertebrate Paleontology. 28 (3): 816–825\. doi:10.1671/0272-4634(2008)28[816:pmpftl]2.0.co;2. ISSN 0272-4634. S2CID 128913932.
9. ^ a b c d e f g h i Wilson Mantilla, Gregory P.; Chester, Stephen G. B.; Clemens, William A.; Moore, Jason R.; Sprain, Courtney J.; Hovatter, Brody T.; Mitchell, William S.; Mans, Wade W.; Mundil, Roland; Renne, Paul R. (2021). "Earliest Palaeocene purgatoriids and the initial radiation of stem primates". Royal Society Open Science. 8 (2): 210050. Bibcode:2021RSOS....810050W. doi:10.1098/rsos.210050. ISSN 2054-5703. PMC 8074693. PMID 33972886.
10. ^ a b c Burger, Benjamin John (2013-10-29). "A new species of the archaic primate Zanycteris from the late Paleocene of western Colorado and the phylogenetic position of the family Picrodontidae". PeerJ. 1: e191. doi:10.7717/peerj.191. ISSN 2167-8359. PMC 3817582. PMID 24255808.
11. ^ a b c d e f g h i O'Leary, Maureen A.; Rose, Kenneth D. (1995-05-12). "New mesonychian dentitions from the Paleocene and Eocene of the Bighorn Basin, Wyoming". Annals of the Carnegie Museum. 64 (2): 147–172\. doi:10.5962/p.215127. ISSN 0097-4463. S2CID 89955337.
12. ^ a b Thewissen, J. G. M. (1990). "Evolution of Paleocene and Eocene Phenacodontidae (Mammalia, Condylarthra)". hdl:2027.42/48629. `{{cite journal}}`: Cite journal requires `|journal=` (help)
13. ^ Shelley, Sarah L.; Williamson, Thomas E.; Brusatte, Stephen L. (2018-07-18). "The osteology of Periptychus carinidens: A robust, ungulate-like placental mammal (Mammalia: Periptychidae) from the Paleocene of North America". PLOS ONE. 13 (7): e0200132. Bibcode:2018PLoSO..1300132S. doi:10.1371/journal.pone.0200132. ISSN 1932-6203. PMC 6051615. PMID 30020948.
14. ^ a b McComas, Katie M.; Eberle, Jaelyn J. (May 2015). "A new earliest Paleocene (Puercan) arctocyonid mammal from the Fort Union Formation, Great Divide Basin, Wyoming, and its phylogenetic position among early 'condylarths'". Journal of Systematic Palaeontology. 14 (6): 445–459\. doi:10.1080/14772019.2015.1066886. S2CID 127411164.
15. ^ Longrich, N.R., Tokaryk, T. and Field, D.J. (2011). "Mass extinction of birds at the Cretaceous–Paleogene (K–Pg) boundary." Proceedings of the National Academy of Sciences, 108(37): 15253-15257. doi:10.1073/pnas.1110395108
16. ^ Houde, Peter W. (1988). "Paleognathous Birds from the Early Tertiary of the Northern Hemisphere". The Auk. 107 (2): 455–456\. doi:10.2307/4087644. ISSN 0004-8038. JSTOR 4087644.
17. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac Estes, Richard (1975). "Lower Vertebrates from the Fort Union Formation, Late Paleocene, Big Horn Basin, Wyoming". Herpetologica. 31 (4): 365–385\. ISSN 0018-0831. JSTOR 3891523.
18. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z Sullivan, Robert M. (January 1982). "Fossil lizards from Swain Quarry "Fort Union Formation," middle Paleocene (Torrejonian), Carbon County, Wyoming". Journal of Paleontology. 56 (4): 996–1010.
19. ^ a b c d Hutchison, J. Howard (2013), Brinkman, Donald B.; Holroyd, Patricia A.; Gardner, James D. (eds.), "New Turtles from the Paleogene of North America", Morphology and Evolution of Turtles, Vertebrate Paleobiology and Paleoanthropology, Dordrecht: Springer Netherlands, pp. 477–497, doi:10.1007/978-94-007-4309-0_26, ISBN 978-94-007-4309-0, retrieved 2022-11-19
20. ^ a b Vitek, Natasha S. (2012-03-11). "Giant fossil soft-shelled turtles of North America". Palaeontologia Electronica. 15 (16): 1–43\. doi:10.26879/299. ISSN 1094-8074.
21. ^ a b Joyce, Walter G.; Claude, Julien (2020-01-15). "An alternative interpretation of the Paleogene turtle Cardichelyon rogerwoodi as a hinged kinosternoid". Journal of Paleontology. 94 (3): 557–567\. Bibcode:2020JPal...94..557J. doi:10.1017/jpa.2019.92. ISSN 0022-3360. S2CID 210976208.
22. ^ a b Lyson, Tyler R.; Joyce, Walter G. (November 2009). "A revision of Plesiobaena (Testudines: Baenidae) and an assessment of baenid ecology across the K/T boundary". Journal of Paleontology. 83 (6): 833–853\. doi:10.1666/09-035.1. ISSN 0022-3360. S2CID 85964417.
23. ^ a b c d e f g h Joyce, Walter G.; Revan, Ariel; Lyson, Tyler R.; Danilov, Igor G. (2009). "Two New Plastomenine Softshell Turtles from the Paleocene of Montana and Wyoming". Bulletin of the Peabody Museum of Natural History. 50 (2): 307. doi:10.3374/014.050.0202. ISSN 0079-032X. S2CID 85505337.
24. ^ a b c d e Brownstein, Chase Doran (November 2022). "Evidence of large sturgeons in the Paleocene of North America". Journal of Paleontology. 97: 218–222\. doi:10.1017/jpa.2022.87. ISSN 0022-3360. S2CID 253653018.
25. ^ a b Brownstein, Chase D.; Near, Thomas J. (2024). "A giant bowfin from a Paleocene hothouse ecosystem in North America". Zoological Journal of the Linnean Society. doi:10.1093/zoolinnean/zlae042. Retrieved 2024-04-30.
26. ^ a b Brownstein, Chase Doran; Lyson, Tyler R. (2022). "Giant gar from directly above the Cretaceous–Palaeogene boundary suggests healthy freshwater ecosystems existed within thousands of years of the asteroid impact". Biology Letters. 18 (6): 20220118. doi:10.1098/rsbl.2022.0118. PMC 9198771. PMID 35702983.
27. ^ a b c d e Murray, Alison M.; Brinkman, Donald B.; DeMar, David G.; Wilson, Gregory P. (2020-03-03). "Paddlefish and sturgeon (Chondrostei: Acipenseriformes: Polyodontidae and Acipenseridae) from lower Paleocene deposits of Montana, U.S.A." Journal of Vertebrate Paleontology. 40 (2): e1775091. Bibcode:2020JVPal..40E5091M. doi:10.1080/02724634.2020.1775091. ISSN 0272-4634. S2CID 222213273.
28. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az ba bb bc bd be bf bg bh bi bj bk bl bm bn bo bp bq br bs bt bu bv bw bx by bz ca cb cc cd ce cf cg ch ci cj ck cl cm cn co cp cq cr cs ct cu cv cw cx cy cz da Hanley, John H.; Flores, Romeo M. (1987). "Taphonomy and Paleoecology of Nonmarine Mollusca: Indicators of Alluvial Plain Lacustrine Sedimentation, Upper Part of the Tongue River Member, Fort Union Formation (Paleocene), Northern Powder River Basin, Wyoming and Montana". PALAIOS. 2 (5): 479–496\. Bibcode:1987Palai...2..479H. doi:10.2307/3514619. ISSN 0883-1351. JSTOR 3514619.
29. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az Manchester, Steven R.; Foster, Alyssa; Lott, Terry A. (2023-05-12). "The Paleocene Horse Creek florule, Tongue River Member of the Fort Union Formation, southeastern Montana, USA". Acta Palaeobotanica. 63 (1): 32–53\. doi:10.35535/acpa-2023-0003. ISSN 0001-6594.
30. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap Donovan, Michael P.; Wilf, Peter; Labandeira, Conrad C.; Johnson, Kirk R.; Peppe, Daniel J. (2014-07-24). "Novel Insect Leaf-Mining after the End-Cretaceous Extinction and the Demise of Cretaceous Leaf Miners, Great Plains, USA". PLOS ONE. 9 (7): e103542. Bibcode:2014PLoSO...9j3542D. doi:10.1371/journal.pone.0103542. ISSN 1932-6203. PMC 4110055. PMID 25058404.
31. ^ a b c d e f g h i j k l m n o p q r Peppe, Daniel J.; Hickey, Leo J. (November 2014). "Fort Union Formation Fossil Leaves (Paleocene, Williston Basin, North Dakota, USA) Indicate Evolutionary Relationships Between Paleocene and Eocene Plant Species". Bulletin of the Peabody Museum of Natural History. 55 (2): 171–189\. doi:10.3374/014.055.0209. ISSN 0079-032X. S2CID 129724520.
32. ^ a b c Kvaček, Zlatko; Manchester, Steven R. (1999). "Eostangeria Barthel (Extinct Cycadales) from the Paleogene of Western North America and Europe". International Journal of Plant Sciences. 160 (3): 621–629\. doi:10.1086/314152. ISSN 1058-5893. S2CID 83978433.

* v
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Chronostratigraphy of Colorado

* v
* t
* e

Cenozoic chronostratigraphy of Colorado

Ph|

| Cz|

| Q|

| Pleistocene|

* Alamosa Formation

|

| Pliocene|

| Zanclean|

* Dry Union Formation
* Ogallala Formation

|

Miocene|

| Messinian|

* Dry Union Formation
* Ogallala Formation

|

Aquitanian|

* Arikaree Formation

* Browns Park Formation
* Cedar Mountain Formation
* Flat Tops Volcanics
* Los Pintos Formation
* Martins Canyon Formation
* North Park Formation
* Santa Fe Formation
* Troublesome Formation
* Trump Formation
* Wagon Tongue Formation

* Grouse Mountain Basalt

Pe|

| Oligocene|

| Chattian|

* Arikaree Formation

|

* Brule Formation
* Central Colorado Volcanics
* Chadron Formation
* Conejos Formation
* Pinnacle Formation
* Pitch Formation

Eocene|

* Blanco Basin Formation
* Cuchara Formation
* D2 Sequence
* Dawson Arkose
* Echo Park Formation
* Farisita Formation
* Huerfano Formation
* Green River Formation
* Poison Canyon Formation
* Uinta Formation
* Wasatch Formation

Paleocene|

* Animas Formation
* Arapahoe Conglomerate
* Bridger Formation
* Denver Formation
* Fort Union Formation
* Middle Park Formation
* Nacimiento Formation
* Ojo Alamo Formation
* Raton Conglomerate
* San Jose Formation
* South Park Formation
* Washakie Formation

* Gravel Mountain Formation
* Independence Mountain Formation

* v
* t
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Mesozoic chronostratigraphy of Colorado

Ph|

| Mz|

| K|

| Upper|

* Benton Formation
* Carlile Shale
* Castle Gate Formation
* Cliff House Sandstone
* Codell Sandstone
* Dakota Group
* Fort Hays Limestone
* Fox Hills Formation
* Fruitland Formation
* Graneros Shale
* Greenhorn Shale
* Hygiene Formation
* Juana Lopez
* Kirtland Formation
* Kremmling Formation
* Lance Formation
* Laramie Formation
* Lewis Formation
* Lion Canyon Formation
* Mancos Shale
* Menefee Formation
* Mowry Shale
* Niobrara Formation
* Pando Porphyry
* Pictured Cliffs Formation
* Pierre Shale
* Point Lookout Formation
* Smoky Hill Chalk
* Trinidad Formation
* Vermejo Formation
* Williams Fork Formation

|

Lower|

* Burro Canyon Formation
* Horsetooth Formation

| Upper|

* Curtis Formation
* Morrison Formation
* Ralston Creek Formation
* Wanakah Formation

|

Middle|

* Carmel Formation
* Entrada Formation
* Garo Formation
* Page Formation
* Sundance Formation

Lower|

* Glen Canyon Formation
* Kayenta Formation
* Navajo Formation
* Wingate Sandstone

Tr|

| Upper|

* Chinle Formation

|

Middle|

| Anisian|

* Chugwater Formation

|

* Jelm Formation
* Moenkopi Formation

Lower|

| Olenekian|

* Chugwater Formation

|

Induan|

* Chugwater Formation
* Lykins Formation
* Taloga Formation

* Moenkopi Formation

* v
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Paleozoic chronostratigraphy of Colorado

Ph|

| Pz|

| P|

| Lopingian|

| Changhsingian|

* Chugwater Formation
* Lykins Formation
* Taloga Formation

|

Cisuralian|

| Asselian|

* Fountain Formation
* Madera Formation

|

* Blaine Formation
* Cedar Hills Formation
* Chase Formation
* Council Grove Formation
* Crestone Conglomerate
* Day Creek Formation
* Falcon Formation
* Forelle Formation
* Glendo Formation
* Glorieta Formation
* Hermosa Formation
* Ingleside Formation
* Kaibab Limestone
* Lansing Formation
* Lyons Formation
* Maroon Formation
* Minnekahta Formation
* Opeche Formation
* Owl Canyon Formation
* Phosphoria Formation
* Sangre de Cristo Formation
* Satanka Formation
* Shawnee Formation
* South Canyon Creek Formation
* Stone Corral Formation
* Sumner Formation
* Wabaunsee Formation
* Weber Formation
* Wellington Formation
* White Horse Group
* Wolfcamp Formation
* Yeso Formation

| ⁋|

| Gzhelian|

* Fountain Formation
* Madera Formation

|

* Atoka Formation
* Belden Formation
* Cherokee Formation
* Eagle Valley Evaporite
* Glen Eyrie Formation
* Gothic Formation
* Hermosa Formation
* Jacque Mountain Formation
* Kansas City Formation
* Kerber Formation
* Keyes Formation
* Marmaton Formation
* Maroon Formation
* Minturn Formation
* Molas Formation
* Morgan Round Valley Formation
* Morrow Formation
* Sharpsdale Formation

| Tournaisian|

* Williams Canyon Formation

|

* Beulah Formation
* Gilman Formation
* Headscrabble Formation
* Leadville Formation
* Molas Formation
* Osage Formation
* Spergen Formation
* St. Louis Formation
* Ste. Genevieve Formation
* Warsaw Formation

| Upper|

| Famennian|

* Williams Canyon Formation

|

* Aneth Formation
* Dyer Formation
* Elbert Formation
* Kinderhook Formation
* Misener Formation
* Ouray Formation
* Parting Formation
* Pinyon Park Formation

| Upper|

* Fremont Limestone
* Viola Formation

|

Middle|

* Harding Sandstone
* Simpson Formation

Lower|

| Tremadocian|

* Dotsero Formation

|

* Arbuckle Formation
* Manitou Formation

| Furongian|

| Stage 10|

* Dotsero Formation

|

Paibian|

* Lodore Formation
* Sawatch Formation

Series 3|

| Guzhangian|

* Lodore Formation
* Sawatch Formation

|

* Reagan Formation
* Tintic Formation

* v
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Precambrian chronostratigraphy of Colorado

pЄ|

| ♇|

| Z|

| Tonian|

* Uinta Mountain Group

|

* Tava Formation

| Siderian|

* Owiyukuts Complex

|

* Uncompahgre Formation

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