Ergilin Dzo Formation
Geological formation
PeriodPaleogene
NamedbyDashzeveg
Year ts1993
RegionDornogovi Province
CountryMongolia
Subunits

From top to bottom:

  • Khetsu Tsav member
  • Ergilin member
  • Shavag member
  • Sevkhul member
  • Zangut member
  • Khubsugul member

The Ergilin Dzo Formation (formerly known as the Ardyn Obo Formation), is a geologic formation in southeastern Mongolia. It preserves fossils of a wide variety of animals, which date back to the late Eocene epoch. The type fauna of the Ergilian Asian land mammal age is defined by the mammalian fossils of this formation.[1]

Depositional environment

Based on the presence of brontotheres and the abundance of herbivorous low-crowned mammals, the Ergilin Dzo Formation has been estimated to be humid and warm/hot with a relatively-closed area.[2][3] However, the absence of primates and rarity of crocodyliforms (known from one specimen currently) in this formation may suggest the paleoenvironment had open areas and was more arid than similarly aged faunal assemblages from elsewhere in Eurasia.[1] Sedimentary analyses suggest the Ergilin Dzo Formation was a floodplain environment with a braided stream network formed by fluvial systems.[4]

Fossil content

In their review of the vertebrate fauna of the formation, Tsubamoto et al. (2022) found that 77 genera and 104 species of vertebrate have been reported from the Ergilin Dzo Formation, representing 22 orders and 49 families. Fossils of mammals, reptiles (including birds), fish and amphibians have all been recovered from the formation since the early 20th Century.[1]

Mammals

81 mammal species have been found in the Ergilin Dzo Formation, with perissodactyls being the most diverse group (33 species reported). Ruminant artiodactyls, rhinocerotoids and brontotheres are the most abundant groups in terms of collected specimen numbers.[1]

Artiodactyls

Artiodactyls reported from the Ergilin Dzo Formation
GenusSpeciesPresenceStratigraphic memberMaterialNotesImages
Anthracotheriidae indet.IndeterminateErgilin Dzo locality.[5]Left astragalus.[5]An anthracothere.
cf. Bothriodoncf. B. sp.Ergilin Dzo & Khoer Dhan localities.[5]Jaw & limb elements.[5]An anthracothere.
BrachyhyopsB. trofimoviKhoer Dzhan locality.[6]Jaw elements.[6]An entelodontid.
B. sp.Ergilin Dzo locality.[6]Right maxilla fragment.[6]An entelodontid.
EntelodonE. gobiensisKhoer Dzhan & Ergilin Dzo localities.[6][7]An entelodontid.
EumeryxE. sp.A deer.
GobiomeryxG. dubiusA leptomerycid.
LophiomeryxL. angaraeA lophiomerycid.
L. sp.A lophiomerycid.
MiomeryxM. altaicusA leptomerycid.
M. sp.A leptomerycid.
PraetragulusP. electusKhoer Dzhan locality.[8]Numerous jaw & limb elements.[8]A hypertragulid.
P. gobiaeErgilin Dzo locality.[8]Jaw elements.[8]A hypertragulid.

Cimolestans

Cimolestans reported from the Formation
GenusSpeciesPresenceStratigraphic memberMaterialNotesImages
GobiopithecusG. khanKhoer Dzhan locality.[9][10]Ergilin Member.[9]Mandibles.[10]A pantolestid.

Didymoconids

Didymoconids reported from the Ergilin Dzo Formation
GenusSpeciesPresenceStratigraphic memberMaterialNotesImages
ArdynictisA. furunculusSkull & jaws.[11]
ErgilictisE. reshetoviErgilin Dzo locality.[12]Jaw elements.[12]

Eulipotyphlans

Eulipotyphlans reported from the Ergilin Dzo Formation
GenusSpeciesPresenceStratigraphic memberMaterialNotesImages
AmphechinusA. sp.Ergilin Dzo locality.[13]Sevkhul Member.[13]Left dentary fragment.[13]A hedgehog.
Ictopidium?I.? sp.A changlelestid.
OligochenusO. grandisErgilin Dzo locality.[13]Sevkhul Member.[13]Right dentary fragment.[13]A gymnure.
Palaeoscaptor?P.? sp.A hedgehog.
Soricinae indet.IndeterminateA shrew.
Tupaiodontinae indet.IndeterminateErgilin Dzo locality.[13]Ergilin Member.[13]Premolar.[13]A changlelestid.

Ferae

Ferae reported from the Ergolin Dzo Formation
GenusSpeciesPresenceStratigraphic memberMaterialNotesImages
AlagtsavbaatarA. indigenusAlag Tsav & Khoer Dzhan localities.[14]Jaw & limb elements.[14]A small feliform.
Amphicyonidae indet.IndeterminateErgilin Dzo locality.[15]Tooth.[15]A bear-dog.
AsiavoratorA. gracilisErgilin Dzo locality.[14]Right mandible fragment.[14]A small feliform.
EofelisE. sp.Khoer Dzhan locality.[14]Jaw elements.[14]A nimravid.
HyaenodonH. chunkhtensisKhoer Dzhan locality.[16][17]Left mandibular corpus.[16]A hyaenodont.
H. eminusKhoer Dzhan & Ergilin Dzo localities.[16]Jaw elements.[11]A hyaenodont.
H. gigasKhoer Dzhan locality.[16]A hyaenodont.
H. incertusKhoer Dzhan & Ergilin Dzo localities.[16]A hyaenodont.
H. mongoliensisKhoer Dzhan & Ergilin Dzo localities.[16]A hyaenodont.
H. pervagusKhoer Dzhan & Ergilin Dzo localities.[16]A hyaenodont.
H. pumilusMandibular ramus.[17]A hyaenodont.
NimravusN. mongoliensisKhoer Dzhan locality.[14]Jaw & limb elements.[14]A nimravid.
Proviverrinae indet.IndeterminateKhoer Dzhan locality.[16]Tooth.[16]A hyaenodont.

Gliriformes

Gliriformes reported from the Ergilin Dzo Formation
GenusSpeciesPresenceStratigraphic memberMaterialNotesImages
ArdynomysA. olseniLower jaw.[11]A rodent.
A. silentiumisA rodent.
A. sp.A rodent.
DesmatolagusD. ardynenseA lagomorph.
D. gobiensisA lagomorph.
D. robustusLower jaws.[11]A lagomorph.
EucricetodonE. sp.A rodent.
Lagomorpha indet.IndeterminateA lagomorph.
ZofiagaleZ. ergilensisErgilin Dzo locality.[18]Right dentary.[18]An anagalid.

Mesonychians

Mesonychians reported from the Ergilin Dzo Formation
GenusSpeciesPresenceStratigraphic memberMaterialNotesImages
MetahapalodectesM. sp.A hapalodectid.
MongolestesM. hadrodensA mesonychid.

Perissodactyls

Perissodactyls reported from the Ergilin Dzo Formation
GenusSpeciesPresenceStratigraphic memberMaterialNotesImages
cf. Allaceropscf. A. sp.Khoer Dzhan.[19]Jaw elements.[19]An eggysodontid.
AmynodonA. sp.An amynodont.
AmynodontopsisA. lunanensisAn amynodont.
ArdyniaA. praecoxKhoer Dzhan.[19]Sevkhul & Ergilin members.[19]Jaw elements.[19]A hyracodontid.
A. sp.Khoer Dzhan.[19]Sevkhul & Ergilin members.[19]Jaw fragments.[19]A hyracodontid.
ArmaniaA. asianaKhoer Dzhan & Ergilin Dzo.[19]Sevkhul & Ergilin Members.[19]Jaw elements.[19]A hyracodontid.
Brontotheriidae indet.IndeterminateA brontothere.
CadurcodonC. ardynensisAn amynodont.
C. sp.An amynodont.
CadurcotheriumC. progressusAn amynodont.
cf. Deperetellacf. D. sp.A deperetellid.
EmbolotheriumE. andrewsiSkull.[20]A brontothere.
E. grangeriKhoer Dzhan.[20]Partial skull.[20]A brontothere.
E. sp.A brontothere.
EomoropusE. sp.An eomoropid.
EubrontotheriumE. clarnoensisErgilin Dzo.[20]Partial skeleton.[20]A brontothere.
JuxiaJ. borissiakiErgilin Dzo locality.[19]Ergilin Member.[19]Jaws & teeth.[19]A paraceratheriid.
cf. Nasampluscf. N. progressusA brontothere.
Paraceratheriidae indet.IndeterminateKhoer Dzhan.[19]Ergilin Member.[19]Teeth.[19]Initially reported as Urtinotherium (or Paraceratherium) sp.
ParacolodonP. inceptusA helaletid.
P. sp.A helaletid.
ProhyracodonP. meridionalisKhoer Dzhan.[19]Sevkhul Member.[19]Jaw elements.[19]A hyracodontid.
P. obrutschewiA hyracodontid.
?P. parvumKhoer Dzhan.[19]Zangut-Sevkhul member.[19]Jaw elements.[19]A hyracodontid.
ProtembolotheriumP. efremoviErgilin Dzo.[20]Skull elements.[20]A brontothere.
RonzotheriumR. brevirostrisA rhinoceros.
R. orientaleErgilin Dzo, Bayan Tsav ravine & Khoer Dzhan.[19]Ergilin Member.[19]Jaw elements.[19]A rhinoceros.
R. sp.Khoer Dzhan.[19]Ergilin Member.[19]Fragment of mandibular ramus.[19]A rhinoceros.
SchizotheriumS. avitumA chalicothere.
SharamynodonS. mongoliensisAn amynodont.
TeleolophusT. magnusA deperetellid.
UrtinotheriumU. parvumA paraceratheriid.
cf. Zaisanamynodoncf. Z. sp.An amynodont.

Reptiles

Reptiles are represented by 20 known species in the formation, with 11 of these being birds.[1]

Birds

Birds reported from the Ergilin Dzo Formation
GenusSpeciesPresenceStratigraphic memberMaterialNotesImages
Accipitridae indet.IndeterminateKhoer Dzhan.[21]Leg bones.[21]An accipitrid.
Anatidae indet.IndeterminateKhoer Dzhan.[21]An anatid.
Ardeidae indet.IndeterminateKhoer Dzhan.[21]A heron.
Cygninae indet.IndeterminateKhoer Dzhan.[21]A swan.
EogrusE. sp.Ergilin Dzo.[21]An eogruid.
ErgilornisE. minorErgilin Dzo.[21]An eogruid.
E. rapidusErgilin Dzo.[21]An eogruid.
E. sp.An eogruid.
GobicathartesG. prodigialipesErgilin Dzo.[22]A New World vulture
Lari indet.IndeterminateKhoer Dzhan.[21]Skull fragment.[21]A shorebird.
Rallidae indet.IndeterminateKhoer Dzhan.[21]A rail.
SonogrusS. gregalisAn eogruid.

Crocodyliforms

Crocodyliforms reported from the Ergilin Dzo Formation
GenusSpeciesPresenceStratigraphic memberMaterialNotesImages
Crocodyliformes indet.IndeterminateErgilin Dzo.[23]Tooth.[23]

Squamates

Squamates reported from the Ergilin Dzo Formation
GenusSpeciesPresenceStratigraphic memberMaterialNotesImages
Agamidae indet.IndeterminateAn agamid lizard.
Lacertilia indet.IndeterminateA lizard.

Turtles

Turtles reported from the Ergilin Dzo Formation
GenusSpeciesPresenceStratigraphic memberMaterialNotesImages
ChrysemysC. sp.
Emydidae gen. et. sp. indet.IndeterminateA terrapin.
ErgilemysE. insolitusA tortoise.
?Melanochelys?M. elongata
Platysternidae gen. et. sp. indet.Indeterminate
Trionychidae gen. et. sp. indet.IndeterminateA softshell turtle.

Amphibians

Amphibians reported from the Ergilin Dzo Formation
GenusSpeciesPresenceStratigraphic memberMaterialNotesImages
Urodela gen. et. sp. indet.IndeterminateA salamander.

Fish

Fish reported from the Formation
GenusSpeciesPresenceStratigraphic memberMaterialNotesImages
AmiaA. sp.A bowfin.
ParasilurusP. sp.A catfish.

See also

References

  1. ^ Tsubamoto, Takehisa; Tsogtbaatar, Khishigjav; Chinzorig, Tsogtbaatar; Egi, Naoko (2022). "A brief review of the updated fossil vertebrate fauna of the upper Eocene Ergilin Dzo Formation, southeastern Mongolia". Memoirs of the Faculty of Science, Ehime University. 24: 64–83.
  2. ^ Prothero, Donald R. (1994). The Eocene-Oligocene transition: paradise lost. Critical moments in paleobiology and earth history series. New York: Columbia University Press. ISBN 978-0-231-08091-0.
  3. ^ Tsubamoto, T.; Egi, N.; Takai, M.; Sein, C.; Maung, Maung (2005). "Middle Eocene ungulate mammals from Myanmar: a review with description of new specimens". Acta Palaeontologica Polonica. S2CID 55777375
  4. ^ Watabe, Mahito (2010-03-31). "Lithostratigraphic and sedimentological analysis of the upper Eocene Ergilin Dzo Formation of Ergilin Dzo locality, Mongolia". Hayashibara Museum of Natural Sciences Research Bulletin. 3: 149–153.
  5. ^ Tsubamoto, Takehisa (2020-03-31). "Additional specimens of the Anthracotheriidae (Mammalia; Artiodactyla) from the upper Eocene Ergilin Dzo Formation of Mongolia". Hayashibara Museum of Natural Sciences Research Bulletin. 3: 143–147.
  6. ^ Tsubamoto, Takehisa; Saneyoshi, Mototaka; Watabe, Mahito; Tsogtbaatar, Khishigjav; Mainbayar, Buurei (2011-12-01). "The Entelodontid Artiodactyl Fauna from the Eocene Ergilin Dzo Formation of Mongolia with Comments on Brachyhyops and the Khoer Dzan Locality". Paleontological Research. 15 (4): 258–268. doi:10.2517/1342-8144-15.4.258. ISSN 1342-8144
  7. ^ Watabe, Mahito (2013-11-29). "New specimens of Entelodon gobiensis (Mammalia; Artiodactyla; Entelodontidae) from the Eocene Ergilin Dzo Formation, Mongolia". Bull. Res. Inst. Nat. Sci., Okayama Univ. Of Sci.. ' (39): 37–41.
  8. ^ Vislobokova, I. A. (Inessa Anatolévna) (1998). A new representative of the Hypertraguloidea (Tragulina, Ruminantia) from the Khoer-Dzan locality in Mongolia, with remarks on the relationships of the Hypertragulidae. New York, NY : American Museum of Natural History.
  9. ^ Dashzeveg, Demberliyn & Russell, Donald E. (December 1992). "Extension of dyspternine Pantolestidae (Mammalia, Cimolesta) in the Early Oligocene of Mongolia". Geobios. 25 (5): 647–650. doi:10.1016/0016-6995(92)80104-L
  10. ^ Tsubamoto, Takehisa; Tsogtbaatar, Khishigjav; Saneyoshi, Mototaka; Buuvei, Mainbayar (January 2011). "A new specimen of Gobiopithecus khan (Mammalia; Pantolesta) from the Eocene Ergilin Dzo Formation, Mongolia". Journal of Fossil Research. 44 (1): 20–23.
  11. ^ Matthew, William Diller & Granger, Walter (1925-10-27). "New creodonts and rodents from the Ardyn Obo Formation of Mongolia". American Museum Novitates. ' (193). hdl:2246/4476
  12. ^ Lopatin, Alexey (January 1997). "New Oligocene Didymoconidae (Mesonychia, Mammalia) from Mongolia and Kazakhstan". Paleontological Journal. 31 (1): 108–119.
  13. ^ Lopatin, Alexey (January 2005). "Late Paleogene Erinaceidae (Insectivora, Mammalia) from the Ergilin Dzo locality, Mongolia". Paleontological Journal. 39 (1): 85–92.
  14. ^ Egi, Naoko; Tsubamoto, Takehisa; Saneyoshi, Mototaka; Tsogtbaatar, Khishigjav; Watabe, Mahito; Mainbayar, Buuvei; Chinzorig, Tsogtbaatar; Khatanbaatar, Purevdorg (2016-02-17). "Taxonomic revisions on nimravids and small feliforms (Mammalia, Carnivora) from the Upper Eocene of Mongolia". Historical Biology. 28 (1–2): 105–119. doi:10.1080/08912963.2015.1012508. ISSN 0891-2963
  15. ^ Egi, Naoko; Tsubamoto, Takehisa; Tsogtbaatar, Khishigjav (2009). "New Amphicyonid (Mammalia: Carnivora) from the Upper Eocene Ergilin Dzo Formation, Mongolia". Paleontological Research. 13 (3): 245. ISSN 1342-8144
  16. ^ Tsubamoto, Takehisa; Watabe, Mahito; Tsogtbaatar, Khishigjav (2008-06-12). "Hyaenodon chunkhtensis and the hyaenodontid fauna from the upper Eocene Ergilin Dzo Formation of Mongolia". Journal of Vertebrate Paleontology. 28 (2): 559–564. doi:10.1671/0272-4634(2008)28[559:HCATHF2.0.CO;2]. ISSN 0272-4634
  17. ^ Lavrov, A. V. (July 2019). "New Material on Small Hyenodons (Hyaenodontinae, Creodonta) from the Paleogene of Mongolia". Paleontological Journal. 53 (4): 418–431. doi:10.1134/S0031030119040063. ISSN 0031-0301
  18. ^ López-Torres, Sergi & Fostowicz-Frelik, Łucja (2018-09-17). "A new Eocene anagalid (Mammalia: Euarchontoglires) from Mongolia and its implications for the group's phylogeny and dispersal". Scientific Reports. 8 (1): 13955. doi:10.1038/s41598-018-32086-x. ISSN 2045-2322. PMC 6141491. PMID 30224674
  19. ^ Dashzeveg, D (1991). "Hyracodontids and rhinocerotids (Mammalia, Perissodactyla, Rhinocerotoidea) from the Paleogene of Mongolia". Palaeovertebrata. 21: 1–84.
  20. ^ Mihlbachler, Matthew C. (2008). "Species Taxonomy, Phylogeny, and Biogeography of the Brontotheriidae (Mammalia: Perissodactyla)". Bulletin of the American Museum of Natural History. 311 (1): 1. doi:10.1206/0003-0090(2008)501[1:STPABO2.0.CO;2]. ISSN 0003-0090
  21. ^ Kurochkin, E. N. (1976-05-21). "A survey of the Paleogene birds of Asia". Collected Papers in Avian Paleontology Honoring the 90th Birthday of Alexander Wetmore. 27: 75–86.
  22. ^ Gorbatcheva, V.; Zelenkov, N.; Bertelli, S. (2025). "An Eocene New World vulture (Aves, Cathartidae) from Mongolia". Papers in Palaeontology. 11 (5). Bibcode:2025PPal...1170041G. doi:10.1002/spp2.70041
  23. ^ Iijima, Masaya; Tsubamoto, Takehisa; Tsogtbaatar, Khishigjav; Chinzorig, Tsogtbaatar; Baasankhuu, Soyol (2019). "Discovery of a crocodyliform tooth from the upper Eocene Ergilin Dzo Formation, Mongolia". Acta Palaeontologica Polonica. 64. doi:10.4202/app.00633.2019