The White River Fauna are fossil animals found in the White River Group of South Dakota, North Dakota, Wyoming, Colorado and Nebraska in the United States. In southwest South Dakota and northwest Nebraska, these fossils are characteristic of the White River Badlands (including Badlands National Park), though they can be found far beyond the limits of the White River watershed.[1]

In Wyoming, the White River Group is undifferentiated, and is more commonly known as the White River Formation. Further east in Nebraska and South Dakota, the group is divided into the Chadron Formation (lower part) and Brule Formation (upper part). Exposures are less well-investigated in northeast Colorado and scattered sites across western North Dakota. The White River Group is overlain by the Sharps Formation in Badlands National Park and the Arikaree Group in northwest Nebraska.

Animals from the White River Group date from the Eocene and Oligocene epochs. The fauna is representative of four North American Land Mammal Ages (NALMAs):

  • Arikareean (late Oligocene - early Miocene, 29.5 - 18.5 million years ago)
  • Whitneyan (mid-Oligocene, 31.8 - 29.5 million years ago)
  • Orellan (early Oligocene, 33.9 - 31.8 million years ago)
  • Chadronian (late Eocene, 37 - 33.9 million years ago)

Birds

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Genus Species Clade Epoch Image Notes
Bathornis
  • B. veredus (type)
  • B. celeripes
  • B. cursor
  • B. fricki
  • B. geographicus
  • B. grallator
  • B. fax?
  • B. minor
Bathornithidae Eocene-Miocene   The type genus of the Bathornithidae, large predatory birds related to seriemas.[2]
Paracrax †Bathornithidae Closely related and similar to the conspecific Bathornis; however, it seems to have occupied more arid environments.[3]

Mammals

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Artiodactyls

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Antracotheres

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Genus Species Clade Epoch Image Notes
Bothriodon
  • B. sp.
Anthracotheriidae  
Elomeryx
  • E. brachyrhynchus
Anthracotheriidae

Camelids

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Genus Species Clade Epoch Image Notes
Poebrotherium
  • P. wilsoni (type)
  • P. chadronensis
  • P. eximium
  • P. franki
  • P. labratum
Camelidae  

Entelodonts

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Genus Species Clade Epoch Image Notes
Archaeotherium
  • A. mortoni (type)
Entelodontidae Oligocene  
Daeodon
  • D. shoshonensis (type)
  • D. humerosum?
†Entelodontidae Miocene  

Leptomerycids

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Genus Species Clade Epoch Image Notes
Leptomeryx Leptomerycidae   The most common fossil found in the area.[4]

Merycoidodontids

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Genus Species Clade Epoch Image Notes
Eporeodon
  • E. major (type)
  • E. occidentalis
  • E. pygmyus
Merycoidodontidae Oligocene  
Leptauchenia †Merycoidodontidae  
Merycoidodon †Merycoidodontidae  
Miniochoerus †Merycoidodontidae  

Protoceratids

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Genus Species Clade Epoch Image Notes
Protoceras Protoceratidae  

Ruminants

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Genus Species Clade Epoch Image Notes
Hypertragulus Hypertragulidae  

Creodonts

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Genus Species Clade Epoch Image Notes
Hyaenodon
  • H. horridus
Hyaenodontidae Eocene - Miocene  

Carnivorans

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Amphiconids

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Genus Species Clade Epoch Image Notes
Daphoneus
  • D. vetus (type)
  • D. hartshorianus
  • D. lambei
  • D. ruber
  • D. socialis
  • D. transversus
Amphicyonidae Eocene-Miocene  
Parictis Amphicynodontinae

Canids

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Genus Species Clade Epoch Image Notes
Archaeocyon
  • A. leptodus (type)
  • A. pavidus
  • A. falkenbachi
Borophaginae Oligocene  
Osbornodon Canidae

Nimravids

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Genus Species Clade Epoch Image Notes
Dinictis
  • D. felina (type)
Nimravidae Eocene-Miocene  
Hoplophoneus
  • H. primaevus (type)
  • H. occidentalis
  • H. strigidens
  • H. cerebralis
  • H. dakotensis
  • H. oharrai
  • H. sicarius
†Nimravidae Eocene-Oligocene  
Nimravus †Nimravidae  

Epoicotheres

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Genus Species Clade Epoch Image Notes
Xenocranium
  • X. pileorivale (type)
Epoicotheriidae Oligocene  

Lagomorphs

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Genus Species Clade Epoch Image Notes
Palaeolagus Leporidae  

Perissodactyls

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Brototheres

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Genus Species Clade Epoch Image Notes
Megacerops Brontotheriidae Eocene - Oligocene  

Equids

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Genus Species Clade Epoch Image Notes
Mesohippus Equidae  
Miohippus Equidae  

Rhinocerotoids

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Amynodonts
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Genus Species Clade Epoch Image Notes
Metamynodon Amynodontidae  
Hyracodontids
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Genus Species Clade Epoch Image Notes
Hyracodon Hyracodontidae Eocene - Oligocene  
Rhinocerotids
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Genus Species Clade Epoch Image Notes
Subhyracodon Rhinocerotidae  

Tapirids

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Genus Species Clade Epoch Image Notes
Protapirus Tapiridae  

Rodents

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Genus Species Clade Epoch Image Notes
Agnotocastor
  • A. praeteredens (type)
  • A. coloradensis
  • A. galushai
  • A. readingi
Castoridae Eocene-Miocene  
Ischyromys Ischyromyidae  

Reptiles

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Crocodilians

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Genus Species NALMA Age Notes Image
Alligator A. prenasalis Chadronian late Eocene The earliest known species of alligator.  

Lizards

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Indeterminate iguanid, skink, and diploglossine (galliwasp) fossils are also known from the White River Group.[5]

Genus Species NALMA Epoch Notes Image
Aciprion A. formosum Orellan early Oligocene An iguanian related to crotaphytids (collared lizards).[6][7]
Cremastosaurus C. carinicollis Chadronian late Eocene A rare and enigmatic squamate based on vertebrae.[6]
"C". rhambastes
Cypressaurus C. sp. Chadronian late Eocene A rare iguanid based on jaw fragments.[5]
Exostinus E. serratus Orellan early Oligocene A rare xenosaurid known from skull fragments.[6][8]
Helodermoides H. tuberculatus Chadronian to Orellan late Eocene to early Oligocene A glyptosaurine anguid (an armored lizard related to glass lizards and alligator lizards). Previously considered a species of Glyptosaurus.[6][9][5]  
Hyporhina H. antiqua Orellan to Whitneyan early-mid Oligocene An amphisbaenian (worm lizard).[6]
H. tertia Chadronian late Eocene
Lowesaurus L. matthewi Orellan to Arikareean Oligocene A rare helodermatid (beaded lizard).[6]
Palaeoxantusia P. cf. P. borealis Chadronian late Eocene A xantusiid (night lizard).[6][5]
Paraphrynosoma P. greeni Orellan early Oligocene A rare iguanian known from a single jaw.[6]
Parophisaurus P. pawneensis Orellan early Oligocene An anguid related to Ophisaurus (eastern glass lizards).[6]
Peltosaurus P. granulosus Chadronian to Arikareean late Eocene to late Oligocene A common glyptosaurine anguid (an armored lizard related to glass lizards and alligator lizards).[6][9][5]  
Polychrus P. charisticus[5] Chadronian late Eocene A rare polychrotine (bush anole) based on jaw fragments.[5]
Rhineura R. coloradoensis Chadronian late Eocene A rhineurid amphisbaenian closely related to the Florida worm lizard (Rhineura floridana).[6][9][5]
R. hatcherii Orellan to Whitneyan early-mid Oligocene
Saniwa S. edura[5] Chadronian late Eocene A rare varanid based on jaw fragments.[5]
Spathorhynchus S. natronicus Chadronian late Eocene A rare rhineurid based on a single skull.[6][5]
Tinosaurus T. sp. Chadronian late Eocene A rare acrodontan based on jaw fragments.[5]
Tuberculacerta[5] T. pearsoni Chadronian late Eocene A rare phrynosomatine (relative of fence lizards) based on jaw fragments.[5]

Snakes

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Genus Species NALMA Epoch Notes Image
Boavus B. cf. occidentalis Chadronian to Orellan late Eocene to early Oligocene A boine boid (true boa).[6]
Calamagras C. angulatus Orellan to Arikareean Oligocene An erycine boid (sand boa).[6][9]
C. murivorus Orellan early Oligocene
Coprophis C. dakotaensis Orellan early Oligocene A rare booid based on eroded fossils found within a mammal coprolite.[6]
Geringophis G. vetus Orellan early Oligocene An erycine boid (sand boa).[6][9]
Helagras H. orellanensis Orellan early Oligocene An erycine boid (sand boa).[6]
Hibernophis[10] H. breithaupti Orellan early Oligocene A booid based on complete skeletons.[10]
Texasophis T. galbreathi Orellan early Oligocene A colubrid.[6]

Turtles

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Indeterminate fossils of an anosteirine carettochelyid and a ptychogastrin geoemydid are also known from the White River Group.[11]

Genus Species NALMA Epoch Notes Image
Apalone A. leucopotamica Chadronian to Orellan late Eocene to early Oligocene A trionychid (softshell turtle).[11]
Chrysemys C. antiqua Chadronian to Whitneyan late Eocene to mid-Oligocene An emydid (pond turtle), sometimes known as "Trachemys" antiqua. A potential relative of modern painted turtles (Chrysemys).[11]
cf. †Echmatemys cf. †E. sp. Chadronian late Eocene A "batagurid" (geoemydid) similar to Echmatemys.[11]
Gopherus G. laticuneus Chadronian to Whitneyan late Eocene to mid-Oligocene A gopher tortoise in the subgenus Oligopherus. Gopherus fossils are also known from the Whitneyan.[11]
Hesperotestudo H. brontops Chadronian late Eocene A testudinid (tortoise). Hesperotestudo-like fossils are also known from the Whitneyan.[11]
Pseudograptemys[11] P. inornata Chadronian late Eocene An emydid (pond turtle) closely related to Graptemys (map turtles).[11]
Stylemys S. amphithorax Chadronian late Eocene A common testudinid (tortoise) related to gopher tortoises (Gopherus). Probably survived into the Whitneyan in the White River area.[11]  
S. nebrascensis Chadronian to Orellan late Eocene to early Oligocene
Xenochelys X. formosa Chadronian late Eocene A kinosternid (mud turtle).[11]

Amphibians

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Genus Species NALMA Epoch Notes Image
Eopelobates †E. grandis Chadronian late Eocene A pelobatid frog related to Pelobates (the European spadefoot toads).[12]

See also

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Further reading

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  • Rachel Benton, The White River Badlands: Geology and Paleontology, Indiana University Press 2015
  • William Berryman Scott, A history of land mammals in the western hemisphere, MacMillan Publishing Company, 1913

References

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  1. ^ Scott, W. B., & Jepsen, G. L. (1940). The Mammalian Fauna of the White River Oligocene: Part IV. Artiodactyla. Transactions of the American Philosophical Society, 28(4), 363–746. https://doi.org/10.2307/1005504
  2. ^ Wetmore, A. (1927). "Fossil Birds from the Oligocene of Colorado" (PDF). Proceedings of the Colorado Museum of Natural History. 7 (2): 1–14.
  3. ^ Wetmore, A. (1927). "Fossil Birds from the Oligocene of Colorado" (PDF). Proceedings of the Colorado Museum of Natural History. 7 (2): 1–14.
  4. ^ Emry, Robert J. (1973). "Stratigraphy and Preliminary Biostratigraphy of the Flagstaff Rim Area, Natrona County, Wyoming". Smithsonian Contributions to Paleobiology (18): 1–43. doi:10.5479/si.00810266.18.1. ISSN 0081-0266.
  5. ^ a b c d e f g h i j k l m n Smith, Krister T. (2006). "A diverse new assemblage of Late Eocene squamates (Reptilia) from the Chadron Formation of North Dakota, USA" (PDF). Palaeontologia Electronica. 9 (2): 5A.
  6. ^ a b c d e f g h i j k l m n o p q r Sullivan, Robert M.; Holman, J. Alan (1996-06-13), Prothero, Donald R.; Emry, Robert J. (eds.), "Squamata", The Terrestrial Eocene-Oligocene Transition in North America (1 ed.), Cambridge University Press, pp. 354–372, doi:10.1017/cbo9780511665431.018, ISBN 978-0-521-43387-7, retrieved 2024-11-02
  7. ^ Scarpetta, Simon G. (2024). "A Palaeogene stem crotaphytid ( Aciprion formosum ) and the phylogenetic affinities of early fossil pleurodontan iguanians". Royal Society Open Science. 11 (1). Bibcode:2024RSOS...1121139S. doi:10.1098/rsos.221139. ISSN 2054-5703. PMC 10776235. PMID 38204790.
  8. ^ Bhullar, Bhart-Anjan S. (2010-07-26). "Cranial osteology of Exostinus serratus (Squamata: Anguimorpha), fossil sister taxon to the enigmatic clade Xenosaurus". Zoological Journal of the Linnean Society. 159 (4): 921–953. doi:10.1111/j.1096-3642.2009.00573.x.
  9. ^ a b c d e Maddox, Dennis; Wall, William P. (1998). "A Systematic Review of the Fossil Lizards and Snakes (Squamata) from the White River Group of Badlands National Park" (PDF). National Park Service Paleontological Research Technical Report NPS/NRGRD/GRDTR-98/01: 4–7.
  10. ^ a b Croghan, Jasmine A; Palci, Alessandro; Onary, Silvio; Lee, Michael S Y; Caldwell, Michael W (2024-06-19). "Morphology and systematics of a new fossil snake from the early Rupelian (Oligocene) White River Formation, Wyoming". Zoological Journal of the Linnean Society. doi:10.1093/zoolinnean/zlae073. ISSN 0024-4082.
  11. ^ a b c d e f g h i j Hutchison, J. Howard (1996-06-13), Prothero, Donald R.; Emry, Robert J. (eds.), "Testudines", The Terrestrial Eocene-Oligocene Transition in North America (1 ed.), Cambridge University Press, pp. 337–353, doi:10.1017/cbo9780511665431.017, ISBN 978-0-521-43387-7, retrieved 2024-11-02
  12. ^ Roček, Zbyněk; Wuttke, Michael; Gardner, James D.; Bhullar, Bhart-Anjan Singh (2014). "The Euro-American genus Eopelobates, and a re-definition of the family Pelobatidae (Amphibia, Anura)". Palaeobiodiversity and Palaeoenvironments. 94 (4): 529–567. Bibcode:2014PdPe...94..529R. doi:10.1007/s12549-014-0169-5. ISSN 1867-1594.