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Willwood Formation

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Coordinates: 44°30′N 108°00′W / 44.5°N 108.0°W / 44.5; -108.0
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Willwood Formation
Stratigraphic range: Thanetian-Ypresian (Clarkforkian-Bridgerian)
~56–48 Ma
TypeGeological formation
Sub-unitsGray Bull beds, Sand Coulee beds, Sand Creek Facies, Wa-1 Zone
Lithology
PrimaryMudstone, shale
OtherSandstone, conglomerate
Location
Coordinates44°30′N 108°00′W / 44.5°N 108.0°W / 44.5; -108.0
Approximate paleocoordinates49°12′N 90°48′W / 49.2°N 90.8°W / 49.2; -90.8
Region Wyoming
Country USA
ExtentBighorn Basin
Type section
Named forShale, mudstone, limestone
Willwood Formation is located in the United States
Willwood Formation
Willwood Formation (the United States)
Willwood Formation is located in Wyoming
Willwood Formation
Willwood Formation (Wyoming)

The Willwood Formation is a sedimentary sequence deposited during the late Paleocene to early Eocene, or Clarkforkian, Wasatchian and Bridgerian in the NALMA classification.[1][2]

Description

It consists of fine grained clastic rocks (mudstone and shale) interbedded with medium grained clastic rocks (sandstone) and sporadic conglomerates. The formation underlies portions of the Bighorn Basin of Big Horn, Hot Springs, Park and Washakie counties of Wyoming.[3]

Dating

Radiometric dating of volcanic tuffs, combined with comparisons with other formations using magnetostratigraphy, using numerous samples from various levels of the formation suggest an age range of 55 – 52 million years ago, placing the Paleocene-Eocene boundary near the base of the formation.[4]

Fossil content

Trace fossils have been found in the Willwood Formation.[5] Fossil birds include Gastornis, Neocathartes and Paracathartes. A fossil alligatorid, namely Orthogenysuchus, was also found in this formation.

Mammals

Bats
Genus Species Presence Material Notes Images
cf. Icaronycteris cf. I. sp. Locality SC-29, Park County, Wyoming.[6] 3 fragmentary specimens.[6]
Cimolestans
Genus Species Presence Material Notes Images
Azgonyx A. gunnelli Localities SC-67, SC-308 and SC-351.[7] A tillodont.
A. sp. Locality SC-67.[7] A larger tillodont than A. gunnelli.
Coryphodon C. sp. Localities FG-61, SC-67 and SC-139.[7] A pantodont.
Ectoganus E. bighornensis Localities HG-3 and SC-67.[7] A taeniodont.
Esthonyx E. spatularius Bighorn Basin,[8] and locality SC-67.[7] Fragmentary left dentary.[7] A tillodont.
Megalesthonyx M. hopsoni Buffalo Basin.[9] A tillodont.
Palaeosinopa P. incerta Bighorn Basin.[10] A pantolestid.
P. lutreola Bighorn Basin.[10] A pantolestid.
P. veterrima Bighorn Basin.[10] A pantolestid.
Eulipotyphlans
Genus Species Presence Material Notes Images
Batodonoides B. vanhouteni Locality SC-303, situated at the 2,110 m level of the formation.[11] Maxilla and dentaries.[11] A geolabidid.
File:The smallest mammal (5040381547).jpg
Leptacodon L. rosei Localities SC-188 and SC-29, Park County, Wyoming.[6] 3 dentaries, 2 maxillae, several isolated teeth and possibly a metatarsal.[6] A nyctitheriid.
Cf. L. sp. A single lower molar.[6] A nyctitheriid.
Limaconyssus L. habrus Locality SC-29, Park County, Wyoming.[6] Left dentary.[6] A nyctitheriid.
Cf. Plagioctenodon cf. P. krausae Locality SC-29, Park County, Wyoming.[6] An isolated first or second lower incisor and the buccal half of an upper molar.[6] A nyctitheriid.
Wyonycteris W. chalix Locality SC-29, Park County, Wyoming.[6] "UM 76910, a right dentary".[6] A nyctitheriid, originally believed to be a bat.
Ferae
Genus Species Presence Material Notes Images
Acarictis A. ryani Locality SC-67.[7] A broken right molar and a left molar.[7] A hyaenodont.
Arfia A. junnei Localities SC-67, SC-69, SC-79, SC-121, SC-308 and SC-348.[7] A hyaenodont.
Cf. Asiabradypus Cf. A. sp. Locality SC-67.[7] An edentulous right lower jaw (UM 87859m).[7] A palaeanodont.
Didymictis D. leptomylus Localities MP-40, SC-67 and SC-79.[7] Skull and teeth.[7] A viverravid.
Dipsalidictis D. platypus Localities SC-67 and SC-141.[7] An oxyaenid.
D. transiens Localities SC-79 and SC-67.[7] An upper left canine and a trigonid of a molar.[7] An oxyaenid.
Miacis M. winkleri Localities SC-67, SC-348 and SC-350.[7] 3 fragmentary dentaries.[7] A miacid.
Palaeanodon P. nievelti Localities SC-67 and SC-121.[7] A palaeanodont.
Palaeonictis P. sp. Locality SC-67.[7] Trigonid of a right molar.[7] An oxyaenid.
Prolimnocyon P. atavus Bighorn Basin.[12] Partial skeleton.[12] A hyaenodont.
P. eerius Localities SC-67 and possibly SC-139.[7] Crushed skull.[7] A hyaenodont.
Prototomus P. deimos Localities SC-67 and SC-349.[7] 4 fragmentary specimens.[7] A hyaenodont.
Viverravus V. bowni Locality SC-67,[7] and locality SC-29, Park County, Wyoming.[6] A viverravid.
V. politus Locality SC-67.[7] A left maxilla.[7] A viverravid.
Marsupials
Genus Species Presence Material Notes Images
Mimoperadectes M. labrus Localities SC-67 and SC-69.[7] Left dentary.[7]
Peradectes P. cf. P. chesteri 2 isolated teeth.[6]
Multituberculates
Genus Species Presence Material Notes Images
Ectypodus E. powelli Locality SC-29, Park County, Wyoming.[6] 10 isolated teeth from at least 2 individuals.[6] A neoplagiaulacid.
E. tardus Locality SC-67.[7] Tooth crowns.[7] A neoplagiaulacid.
Primatomorphs
Genus Species Presence Material Notes Images
Anemorhysis A. pattersoni Upper part of the formation.[13] An omomyid.
A. wortmani Upper part of the formation.[13] An omomyid.
Arapahovius A. advena Northwest Wyoming.[14] An omomyid.
Arctodontomys A. wilsoni Locality SC-67.[7] Small sample of teeth.[7] A microsyopid.
Cantius C. abditus A substantially complete skull and mandible.[15] An adapiform.
C. torresi Localities SC-67 and SC-69.[7] An adapiform.
Carpolestes C. cf. C. nigridens Locality SC-29, Park County, Wyoming.[6] A right dentary.[6] A carpolestid.
Chlororhysis C. incomptus Upper part of the formation.[13] An omomyid.
Micromomys M. willwoodensis Clark's Fork Basin.[16] A micromomyid.
Microsyops M. latidens Southern Bighorn Basin.[17] Over a thousand specimens.[17] A plesiadapiform.
Cf. Niptomomys Cf. N. sp. Locality SC-67.[7] An edentulous right dentary.[7] A microsyopid.
Phenacolemur P. praecox Localities SC-67 and SC-348.[7] Right and left dentaries.[7] A paramomyid.
P. willwoodensis Upper part of the formation.[18] A paramomyid.
Steinius S. annectens Northwest Wyoming.[14] An omomyid.
Tatmanius T. szalayi Northwest Wyoming.[14] An omomyid.
Tinimomys T. graybullensis The lingual half of a right upper molar.[6] A microsyopid.
Worlandia cf. W. sp. Locality SC-29, Park County, Wyoming.[6] 2 isolated teeth.[6] A plagiomenid colugo.
Rodents
Genus Species Presence Material Notes Images
Acritoparamys Cf. A. atavus Locality SC-67.[7] A small isolated lower incisor (UM 86003m).[7]
A. atwateri Localities SC-67, SC-308 and SC-351.[7] Several dentaries and teeth.[7]
Paramys P. taurus Localities SC-67, SC-139 and SC-350.[7] Jaw fragments and incisors.[7]
Ungulates
Genus Species Presence Material Notes Images
Cardiolophus C. radinskyi UM 64913.[19] An isectolophid.
Copecion C. davisi Localities BR-2, SC-51, SC-67, SC-69, SC-79, SC-139, SC-308, SC-345, SC-348, SC-349 and SC-351.[7] A phenacodontid.
Chriacus C. badgleyi Localities SC-67, SC-79, SC-121 and SC-342.[7] An arctocyonid.
Diacodexis D. ilicis Localities SC-67 and SC-308.[7] A dichobunid.
Dissacus D. praenuntius Locality SC-67.[7] Teeth.[7] A mesonychid.
Ectocion E. osbornianus Locality SC-67 and SC-351.[7] 2 fragmentary dentaries.[7] A phenacodontid.
E. parvus Localities HG-3, SC-67, SC-69, SC-121, SC-139, SC-182, SC-308 and SC-351.[7] A phenacodontid.
Homogalax H. protapirinus Bighorn Basin.[20] A skull (YPM(PU) 16168),[20] and several other specimens.[21][19] An isectolophid.
Hyopsodus H. loomisi Localities SC-67, SC-69, SC-79, SC-121, SC-308 and SC-342.[7] A hyopsodontid.
Hyracotherium H. grangeri Locality SC-67.[7] 2 isolated teeth.[7] An equid.
H. sandrae Localities FG-61, SC-67, SC-69, SC-79, SC-121 and SC-139.[7] An equid.
Meniscotherium M. priscum Locality SC-67(?)[7] Left dentary fragment.[7] A phenacodontid.
Pachyaena P. ossifraga Locality SC-348.[7] Trigonid of a right molar.[7] A mesonychid.
Phenacodus P. cf. P. intermedius Localities SC-67 and SC-141.[7] A phenacodontid.
Princetonia P. yalensis Locality SC-121(?)[7] Right dentary.[7] An arctocyonid.
Thryptacodon T. barae Localities MP-38 and SC-121.[7] An arctocyonid.
Xenicohippus Lower part of the Upper Willwood Formation.[22] A hyracotheriine.

Reptiles

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Birds
Genus Species Presence Material Notes Images
Aves indet. Localities SC-67 and SC-121.[7] A cervical vertebra and proximal part of a carpometacarpus.[7] An indeterminate bird.
Calcardea C. junnei "UM 76882, anterior part of sternum, partial left coracoid. nearly complete right coracoid, partial left humerus. two nearly complete vertebrae. fragmentary left and right tarsometatarsi, and several phalanges, all probably representing a single individual bird."[6] Originally thought to be a heron, now thought to be related to Vastanavis.[23]
Diatryma D. gigantea Several specimens.[24] Now deemed a junior synonym of Gastornis.
Eogeranoides E. campivagus "Fragmentary tibiotarsus and tarsometatarsus remains".[25] A dubious geranoidid, may be a junior synonym of Paragrus prentici.
Gastornis G. gigantea Several specimens.[24] A gastornithiform.
Geranoides G. jepseni Elk Creek, Bighorn Basin.[25] A geranoidid, now deemed a junior synonym of Palaeophasianus meleagroides.
Microolithus M. wilsoni Partial eggs.[26] Fossil bird eggs.
Palaeophasianus "P." incompletus "A fragmentary distal end of a tarsometatarsus".[25] A very large possible geranoidid, may actually belong to the genus Paragrus or be outside Geranoididae entirely.
P. meleagroides Elk Creek, Bighorn Basin.[25] A geranoidid.
?P. sp. AMNH 5156.[25] A geranoidid.
Paracathartes P. howardae [27] A lithornithid.
Paragrus P. prentici [25] A geranoidid.
Primoptynx P. poliotauros Specimen including all major postcranial bones.[28] A large owl.
Sandcoleus S. copiosus Clark Quadrangale, Park County, Wyoming.[29] "Two articulated partial skeletons and a number of other elements".[29] A sandcoleid mousebird.
Crocodilians
Genus Species Presence Material Notes Images
Allognathosuchus A. sp. Localities SC-67, SC-139, SC-342 and SC-349.[7] An alligatorid.
Crocodilia indet. Localities SC-67, SC-69 and SC-121.[7] Dermal scutes and vertebral centra.[7] May represent either large Allognathosuchus or small Leidyosuchus.
Leidyosuchus L. sp. Localities SC-67, SC-79, SC-139, SC-342, SC-345 and SC-350.[7]
Orthogenysuchus O. olseni [30] A caiman.
Pristichampsus P. sp. Locality SC-348.[7] A single tooth (UM 83817m).[7]
Squamates
Genus Species Presence Material Notes Images
Anguidae indet. 2 fragmentary dentaries (UM 76872 and 76873).[6] A very small anguid lizard.[6]
Anguimorpha A dentary, maxilla and 1 or 2 premaxillae (UM 76874-76875, 76878-76879(?), and 768811).[6] A gerrhonotine or diploglossine.[6]
Anguimorph CG "UCMP 150871, 150872 (jaw frag-ments), 150920 (jaw fragment), 150969 (parietal fragment),151038 (left frontal), 151067 (right maxilla fragment), 151095 (right maxilla fragment), 167499 (right maxilla fragment), 167553 (left maxilla fragment)".[31]
Anniealexandria A. gansi UCMP locality V99019.[31] Skull fragments and vertebrae.[31] An amphisbaenian.
Anolbanolis A. banalis UCMP locality V99019.[31] An iguanian.
Apodosauriscus A. thermophilus UCMP locality V99019.[31] Skull fragments.[31] An anguid.
Blutwurstia B. oliviae Clarks Fork Basin.[32] A xenosaurid.
cf. Eodiploglossus cf. E. sp. CG "UCMP 150916 (right maxilla fragment), 150919 (right frontal), 150962 (partial left frontal), 151070, 151071 (skull fragments), 167338 (partial right frontal), 167426 (left maxilla fragment), 167447 (left maxilla fragment), 167456 (jaw fragment),?167527 (right pterygoid fragment), 167602 (right dentary fragment), 400180 (right maxilla fragment)".[31] An anguid.
Gaultia G. silvaticus UCMP locality V99019.[31] A glyptosaurine.
Gerrhonotinae Gerrhonotine CG Skull fragments.[31] An alligator lizard.
Glyptosaurinae Glyptosaurine CG "UCMP 151033 (right maxilla fragment), ?151068 (left pterygoid fragment), 151935 (parietal fragment), 167269 (parietal fragment),?167613 (right palatine fragment)."[31] A glyptosaurine.
Iguanidae Iguanid CG "UCMP 151078 (right dentary fragment), 400156 (partial right postorbital), 400169 (partial right squamosal)".[31] An iguanid lizard.
Lacertilia indet. Localities SC-67 and SC-308.[7] Vertebrae.[7] Indeterminate lizards.
Melanosaurus M. maximus A frontal, numerous osteoderms and vertebrae.[7] A glyptosaurine.
Palaeoxantusia P. sp. CG Skull fragments.[31] A night lizard.
Proxestops Cf. P. sp. Locality MP-40.[7] UM 88170m (2 osteoderms).[7] A glyptosaurine.
P. sp. CG Skull fragments.[31] A glyptosaurine.
Provaranosaurus cf. P. sp. CG "UCMP 167299 (right dentary fragment)".[31] A xenosaurid.
cf. Saniwa cf. S. sp. CG-1 "UCMP 150921 (jaw fragment with partial tooth), 151099 (premaxilla), 167572 (jaw fragment with tooth)".[31] A varanid.
cf. S. sp. CG-2 "UCMP 150873 (right dentary fragment with tooth), 150971 (tooth), 167324 (distal right humerus), 167336 (edentulous left dentary fragment), 167355 (parietal fragment)".[31] A varanid.
Suzanniwana S. patriciana UCMP locality V99019.[31] An iguanid.
Varanoidea A dentary and maxilla (UM 76876 and 768771).[6] One or possibly 2 species of Parasaniwa or Provaranosaurus-like varanoids.[6]
Xantusiidae Xantusiid CG "UCMP 150827 (right maxilla fragment), 150965 (maxilla fragment), 150970 (right maxilla fragment), 167413 (left frontal fragment), 167495 (right maxilla fragment), 167575 (premaxilla), 167599 (right maxilla fragment), 167600 (left maxilla fragment)".[31] A night lizard.
Testudines
Genus Species Presence Material Notes Images
Chelonia indet. Localities SC-67, SC-121 and SC-348.[7] Several pieces of the carapace and plastron.[7] Indeterminate medium to large turtles.
Echmatemys E. sp. Locality SC-67.[7] Much of the plastron and several peripherals or pleurals from the carapace (UM 83627), and a peripheral (UM 66617m).[7]
Gomphochelys G. nanus Southeastern Bighorn Basin, Washakie County, Wyoming.[33] A dermatemydid.
Cf. Plastomenus Cf. P. sp. Localities SC-67 and SC-350.[7] Fragmentary pieces of the carapace and plastron.[7] A trionychid.

Amphibians

Amphibians
Genus Species Presence Material Notes Images
Anura Distal end of a humerus (UM 76883).[6] A small frog.
Urodela Numerous vertebrae, UM 76871 (a-j).[6] A small salamander.

Fish

Fish
Genus Species Presence Material Notes Images
Amia A. sp. Localities SC-67 and SC-342.[7] Isolated cervical vertebrae, and a concretion of broken bones including 1 or 2 tooth-bearing bones likely belonging to Amia. A bowfin.
Cuneatus C. maximus [34] A large gar.
Lepisosteus L. sp. "Mostly diamond-shaped ganoid scales, but some specimens include distinct opisthocoelous vertebrae, basioccipitals and other cranial elements."[7] A gar.

Invertebrates

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
Insects
Genus Species Presence Material Notes Images
Naktodemasis N. bowni Bighorn Basin.[35] "Burrows composed of nested ellipsoidal packets backfilled with thin, tightly spaced, menisci subparallel to the bounding packet."[35] Burrows likely constructed by burrowing bugs or cicada nymphs.[35]
Gastropods
Genus Species Presence Material Notes Images
Cf. Albertanella Cf. A. minuta [6] A pupillid.
Discus D. ralstonensis Many individuals (some juvenile specimens).[6] An endodontid.
Elimia or Pleurocera E. or P. sp. Some 25 specimens, many are internal molds.[7] A pleurocerid.
Grangerella cf. G.(?) phenacodorum 2 specimens originally referred to Protoboysia complicata.[6] A grangerellid.
G. sinclairi [6] A grangerellid.
Cf. Gyraulus Cf. G. sp. Locality SC-69.[7] A poorly-preserved planispiral internal mold.[7] A pulmonatan.
Hendersonia H. evanstonensis Several specimens, none preserving the operculum.[6] A helicinid.
Holospira H. sp. Localities SC-67, SC-139, SC-345 and SC-349.[7] 7 individuals.[7] An urocoptid.
"Hydrobia" "H." sp. Locality SC-69.[7] "A very small, dextral, high-spired shell with 9 whorls".[7] A hydrobiid.
Cf. Microphysula Cf. M. sp. A single individual.[6] A sagdid.
Oreohelix O. megarche A single specimen (UM(I) 65404).[6] An oreohelicid.
Cf. Pupilla Cf. P. sp. UM(I) 654071.[6] A pupillid.

Plants

Plants
Genus Species Presence Material Notes Images
Celtis C. phenacodorum Endocarps.[7] An urticale.

Wasatchian correlations

Wasatchian correlations in North America
Formation Wasatch DeBeque Claron Indian Meadows Pass Peak Tatman Willwood Golden Valley Coldwater Allenby Kamloops Ootsa Lake Margaret Nanjemoy Hatchetigbee Tetas de Cabra Hannold Hill Coalmont Cuchara Galisteo San Jose Ypresian (IUCS) • Itaboraian (SALMA)
Bumbanian (ALMA) • Mangaorapan (NZ)
Basin Powder River
Uinta
Piceance
Colorado Plateau
Wind River
Green River
Bighorn		 Piceance
Colorado Plateau


Wind River



Green River





Bighorn		 Williston Okanagan Princeton Buck Creek Nechako Sverdrup Potomac GoM Laguna Salada Rio Grande North Park Raton Galisteo San Juan
Willwood Formation is located in North America
Willwood Formation
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Willwood Formation (North America)
Country  United States  Canada  United States  Mexico  United States
Copelemur
Coryphodon
Diacodexis
Homogalax
Oxyaena
Paramys
Primates
Birds
Reptiles
Fish
Insects
Flora
Environments Alluvial-fluvio-lacustrine Fluvial Fluvial Fluvio-lacustrine Fluvial Lacustrine Fluvio-lacustrine Deltaic-paludal Shallow marine Fluvial Shallow marine Fluvial Fluvial
Wasatchian volcanoclastics

Wasatchian fauna

Wasatchian flora
Volcanic Yes No Yes No Yes No Yes No Yes No

See also

References

  1. ^ Willwood Formation at Fossilworks.org
  2. ^ Neasham & Vondra, 1972
  3. ^ "Willwood Formation". USGS.
  4. ^ Tauxe et al., 1994
  5. ^ Bown & Kraus, 1982
  6. ^ 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 D., Gingerich, Philip (1987). Early Eocene bats (Mammalia, Chiroptera) and other vertebrates in freshwater limestones of the Willwood Formation, Clark's Fork Basin, Wyoming. Museum of Paleontology, University of Michigan. OCLC 17313505.{{cite book}}: CS1 maint: multiple names: authors list (link)
  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 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 Autor., Gingerich, Philip D. (1989). New earliest Wasatchian mammalian fauna from the eocene of northwestern Wyoming : composition and diversity in a rarely sampled high-floodplain assemblage. University of Michigan. OCLC 1066072691.{{cite book}}: CS1 maint: multiple names: authors list (link)
  8. ^ Rose, Kenneth D.; Rana, Rajendra S.; Sahni, Ashok; Kumar, Kishor; Singh, Lachham; Smith, Thierry (June 2009). "First Tillodont from India: Additional Evidence for an Early Eocene Faunal Connection between Europe and India?". Acta Palaeontologica Polonica. 54 (2): 351–355. doi:10.4202/app.2008.0067. ISSN 0567-7920.
  9. ^ Rose, K. (2009). "A NEW TILLODONT FROM THE EOCENE UPPER WILLWOOD FORMATION OF WYOMING KENNETH D. ROSE A NEW TILLODONT FROM THE EOCENE UPPER WILLWOOD FORMATION OF WYOMING". www.semanticscholar.org. Retrieved 2022-09-02.
  10. ^ a b c Dunn, Rachel H.; Rose, Kenneth D. (July 2015). "Evolution of early Eocene Palaeosinopa (Mammalia, Pantolestidae) in the Willwood Formation of the Bighorn Basin, Wyoming". Journal of Paleontology. 89 (4): 665–694. doi:10.1017/jpa.2015.31. ISSN 0022-3360.
  11. ^ a b Bloch, Jonathan I.; Rose, Kenneth D.; Gingerich, Philip D. (August 1998). "New Species of Batodonoides (Lipotyphla, Geolabididae) from the Early Eocene of Wyoming: Smallest Known Mammal?". Journal of Mammalogy. 79 (3): 804. doi:10.2307/1383090. ISSN 0022-2372.
  12. ^ a b Gebo, Daniel L.; Rose, Kenneeth D. (1993). "Skeletal Morphology and Locomotor Adaptation in Prolimnocyon atavus, an Early Eocene Hyaenodontid Creodont". Journal of Vertebrate Paleontology. 13 (1): 125–144. ISSN 0272-4634.
  13. ^ a b c Bown, Thomas M.; Rose, Kenneth D. (1984). "Reassessment of Some Early Eocene Omomyidae, with Description of a New Genus and Three New Species". Folia Primatologica. 43 (2–3): 97–112. doi:10.1159/000156175. ISSN 0015-5713.
  14. ^ a b c Bown, Thomas M.; Rose, Kenneth D. (1991-06-01). "Evolutionary relationships of a new genus and three new species of Omomyid primates (Willwood Formation, Lower Eocene, Bighorn Basin, Wyoming)". Journal of Human Evolution. 20 (6): 465–480. doi:10.1016/0047-2484(91)90020-V. ISSN 0047-2484.
  15. ^ Rose, K.; Macphee, R.; Alexander, J. P. (1999). "Skull of Early Eocene Cantius abditus (Primates:Adapiformes) and its phylogenetic implications, with a reevaluation of "Hesperolemur" actius". American journal of physical anthropology. doi:10.1002/(SICI)1096-8644(199908)109:4<523::AID-AJPA8>3.0.CO;2-U.
  16. ^ Rose, Kenneth D.; Bown, Thomas M. (1982). "New Plesiadapiform Primates from the Eocene of Wyoming and Montana". Journal of Vertebrate Paleontology. 2 (1): 63–69. ISSN 0272-4634.
  17. ^ a b Selig, Keegan R.; Silcox, Mary T. (2021-09-09). "The largest and earliest known sample of dental caries in an extinct mammal (Mammalia, Euarchonta, Microsyops latidens) and its ecological implications". Scientific Reports. 11 (1): 15920. doi:10.1038/s41598-021-95330-x. ISSN 2045-2322.
  18. ^ Silcox, Mary T.; Rose, Kenneth D.; Bown, Thomas M. (November 2008). "Early Eocene Paromomyidae (Mammalia, Primates) from the southern Bighorn Basin, Wyoming: Systematics and evolution". Journal of Paleontology. 82 (6): 1074–1113. doi:10.1666/07-116.1. ISSN 0022-3360.
  19. ^ a b Smith, Thierry; Solé, Floréal; Missiaen, Pieter; Rana, Rajendra; Kumar, Kishor; Sahni, Ashok; Rose, Kenneth (2015-09-08). "First early Eocene tapiroid from India and its implication for the paleobiogeographic origin of perissodactyls". Palaeovertebrata. doi:10.18563/pv.39.2.e5. ISSN 0031-0247.
  20. ^ a b Holbrook, Luke Thomas; Lucas, Spencer G.; Emry, Robert J. (December 2004). "Skulls of the Eocene perissodactyls (Mammalia) Homogalax and Isectolophus". Journal of Vertebrate Paleontology. 24 (4): 951–956.
  21. ^ Rose, Kenneth D. (December 1996). "SKELETON OF EARLY EOCENE HOMOGALAX AND THE ORIGIN OF PERISSODACTYLA". Palaeovertebrata. 25 (2–4): 243–260.
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Bibliography

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