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]

Ergilin Dzo Formation
Stratigraphic range: Upper Eocene
TypeGeological formation
Sub-unitsFrom top to bottom:
  • Khetsu Tsav member
  • Ergilin member
  • Shavag member
  • Sevkhul member
  • Zangut member
  • Khubsugul member
Location
RegionDornogovi Province
Country Mongolia
Type section
Named byDashzeveg
Year defined1993

Depositional environment edit

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 edit

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 edit

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 edit

Artiodactyls reported from the Ergilin Dzo Formation
Genus Species Presence Stratigraphic member Material Notes Images
Anthracotheriidae indet. Indeterminate Ergilin Dzo locality.[5] Left astragalus.[5] An anthracothere.
cf. Bothriodon cf. B. sp. Ergilin Dzo & Khoer Dhan localities.[5] Jaw & limb elements.[5] An anthracothere.
Brachyhyops B. trofimovi Khoer Dzhan locality.[6] Jaw elements.[6] An entelodontid.
B. sp. Ergilin Dzo locality.[6] Right maxilla fragment.[6] An entelodontid.
Entelodon E. gobiensis Khoer Dzhan & Ergilin Dzo localities.[6][7] An entelodontid.
Eumeryx E. sp. A deer.
Gobiomeryx G. dubius A leptomerycid.
Lophiomeryx L. angarae A lophiomerycid.
L. sp. A lophiomerycid.
Miomeryx M. altaicus A leptomerycid.
M. sp. A leptomerycid.
Praetragulus P. electus Khoer Dzhan locality.[8] Numerous jaw & limb elements.[8] A hypertragulid.
P. gobiae Ergilin Dzo locality.[8] Jaw elements.[8] A hypertragulid.

Cimolestans edit

Cimolestans reported from the Formation
Genus Species Presence Stratigraphic member Material Notes Images
Gobiopithecus G. khan Khoer Dzhan locality.[9][10] Ergilin Member.[9] Mandibles.[10] A pantolestid.

Didymoconids edit

Didymoconids reported from the Ergilin Dzo Formation
Genus Species Presence Stratigraphic member Material Notes Images
Ardynictis A. furunculus Skull & jaws.[11]
Ergilictis E. reshetovi Ergilin Dzo locality.[12] Jaw elements.[12]

Eulipotyphlans edit

Eulipotyphlans reported from the Ergilin Dzo Formation
Genus Species Presence Stratigraphic member Material Notes Images
Amphechinus A. sp. Ergilin Dzo locality.[13] Sevkhul Member.[13] Left dentary fragment.[13] A hedgehog.
Ictopidium? I.? sp. A changlelestid.
Oligochenus O. grandis Ergilin Dzo locality.[13] Sevkhul Member.[13] Right dentary fragment.[13] A gymnure.
Palaeoscaptor? P.? sp. A hedgehog.
Soricinae indet. Indeterminate A shrew.
Tupaiodontinae indet. Indeterminate Ergilin Dzo locality.[13] Ergilin Member.[13] Premolar.[13] A changlelestid.

Ferae edit

Ferae reported from the Ergolin Dzo Formation
Genus Species Presence Stratigraphic member Material Notes Images
Alagtsavbaatar A. indigenus Alag Tsav & Khoer Dzhan localities.[14] Jaw & limb elements.[14] A small feliform.
Amphicyonidae indet. Indeterminate Ergilin Dzo locality.[15] Tooth.[15] A bear-dog.
Asiavorator A. gracilis Ergilin Dzo locality.[14] Right mandible fragment.[14] A small feliform.
Eofelis E. sp. Khoer Dzhan locality.[14] Jaw elements.[14] A nimravid.
Hyaenodon H. chunkhtensis Khoer Dzhan locality.[16][17] Left mandibular corpus.[16] A hyaenodont.
H. eminus Khoer Dzhan & Ergilin Dzo localities.[16] Jaw elements.[11] A hyaenodont.
H. gigas Khoer Dzhan locality.[16] A hyaenodont.
H. incertus Khoer Dzhan & Ergilin Dzo localities.[16] A hyaenodont.
H. mongoliensis Khoer Dzhan & Ergilin Dzo localities.[16] A hyaenodont.
H. pervagus Khoer Dzhan & Ergilin Dzo localities.[16] A hyaenodont.
H. pumilus Mandibular ramus.[17] A hyaenodont.
Nimravus N. mongoliensis Khoer Dzhan locality.[14] Jaw & limb elements.[14] A nimravid.
Proviverrinae indet. Indeterminate Khoer Dzhan locality.[16] Tooth.[16] A hyaenodont.

Gliriformes edit

Gliriformes reported from the Ergilin Dzo Formation
Genus Species Presence Stratigraphic member Material Notes Images
Ardynomys A. olseni Lower jaw.[11] A rodent.
A. silentiumis A rodent.
A. sp. A rodent.
Desmatolagus D. ardynense A lagomorph.
D. gobiensis A lagomorph.
D. robustus Lower jaws.[11] A lagomorph.
Eucricetodon E. sp. A rodent.
Lagomorpha indet. Indeterminate A lagomorph.
Zofiagale Z. ergilensis Ergilin Dzo locality.[18] Right dentary.[18] An anagalid.

Mesonychians edit

Mesonychians reported from the Ergilin Dzo Formation
Genus Species Presence Stratigraphic member Material Notes Images
Metahapalodectes M. sp. A hapalodectid.
Mongolestes M. hadrodens A mesonychid.

Perissodactyls edit

Perissodactyls reported from the Ergilin Dzo Formation
Genus Species Presence Stratigraphic member Material Notes Images
cf. Allacerops cf. A. sp. Khoer Dzhan.[19] Jaw elements.[19] An eggysodontid.
Amynodon A. sp. An amynodont.
Amynodontopsis A. lunanensis An amynodont.
Ardynia A. praecox Khoer 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.
Armania A. asiana Khoer Dzhan & Ergilin Dzo.[19] Sevkhul & Ergilin Members.[19] Jaw elements.[19] A hyracodontid.
Brontotheriidae indet. Indeterminate A brontothere.
Cadurcodon C. ardynensis An amynodont.
C. sp. An amynodont.
Cadurcotherium C. progressus An amynodont.
cf. Deperetella cf. D. sp. A deperetellid.
Embolotherium E. andrewsi Skull.[20] A brontothere.
E. grangeri Khoer Dzhan.[20] Partial skull.[20] A brontothere.
E. sp. A brontothere.
Eomoropus E. sp. An eomoropid.
Eubrontotherium E. clarnoensis Ergilin Dzo.[20] Partial skeleton.[20] A brontothere.
Juxia J. borissiaki Ergilin Dzo locality.[19] Ergilin Member.[19] Jaws & teeth.[19] A paraceratheriid.
cf. Nasamplus cf. N. progressus A brontothere.
Paraceratheriidae indet. Indeterminate Khoer Dzhan.[19] Ergilin Member.[19] Teeth.[19] Initially reported as Urtinotherium (or Paraceratherium) sp.
Paraceratherium P. parvum A paraceratheriid.
Paracolodon P. inceptus A helaletid.
P. sp. A helaletid.
Prohyracodon P. meridionalis Khoer Dzhan.[19] Sevkhul Member.[19] Jaw elements.[19] A hyracodontid.
P. obrutschewi A hyracodontid.
?P. parvum Khoer Dzhan.[19] Zangut-Sevkhul member.[19] Jaw elements.[19] A hyracodontid.
Protembolotherium P. efremovi Ergilin Dzo.[20] Skull elements.[20] A brontothere.
Ronzotherium R. brevirostris A rhino.
R. orientale Ergilin Dzo, Bayan Tsav ravine & Khoer Dzhan.[19] Ergilin Member.[19] Jaw elements.[19] A rhino.
R. sp. Khoer Dzhan.[19] Ergilin Member.[19] Fragment of mandibular ramus.[19] A rhino.
Schizotherium S. avitum A chalicothere.
Sharamynodon S. mongoliensis An amynodont.
Teleolophus T. magnus A deperetellid.
cf. Zaisanamynodon cf. Z. sp. An amynodont.

Reptiles edit

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

Birds edit

Birds reported from the Ergilin Dzo Formation
Genus Species Presence Stratigraphic member Material Notes Images
Accipitridae indet. Indeterminate Khoer Dzhan.[21] Leg bones.[21] An accipitrid.
Anatidae indet. Indeterminate Khoer Dzhan.[21] An anatid.
Ardeidae indet. Indeterminate Khoer Dzhan.[21] A heron.
Cygninae indet. Indeterminate Khoer Dzhan.[21] A swan.
Eogrus E. sp. Ergilin Dzo.[21] An eogruid.
Ergilornis E. minor Ergilin Dzo.[21] An eogruid.
E. rapidus Ergilin Dzo.[21] An eogruid.
E. sp. An eogruid.
Lari indet. Indeterminate Khoer Dzhan.[21] Skull fragment.[21] A shorebird.
Rallidae indet. Indeterminate Khoer Dzhan.[21] A rail.
Sonogrus S. gregalis An eogruid.

Crocodyliforms edit

Crocodyliforms reported from the Ergilin Dzo Formation
Genus Species Presence Stratigraphic member Material Notes Images
Crocodyliformes indet. Indeterminate Ergilin Dzo.[22] Tooth.[22]

Squamates edit

Squamates reported from the Ergilin Dzo Formation
Genus Species Presence Stratigraphic member Material Notes Images
Agamidae indet. Indeterminate An agamid lizard.
Lacertilia indet. Indeterminate A lizard.

Turtles edit

Turtles reported from the Ergilin Dzo Formation
Genus Species Presence Stratigraphic member Material Notes Images
Chrysemys C. sp.
Emydidae gen. et. sp. indet. Indeterminate A terrapin.
Ergilemys E. insolitus A tortoise.
?Melanochelys ?M. elongata
Platysternidae gen. et. sp. indet. Indeterminate
Trionychidae gen. et. sp. indet. Indeterminate A softshell turtle.

Amphibians edit

Amphibians reported from the Ergilin Dzo Formation
Genus Species Presence Stratigraphic member Material Notes Images
Urodela gen. et. sp. indet. Indeterminate A salamander.

Fish edit

Fish reported from the Formation
Genus Species Presence Stratigraphic member Material Notes Images
Amia A. sp. A bowfin.
Parasilurus P. sp. A catfish.

See also edit

References edit

  1. ^ a b c d e 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" (PDF). 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. ^ a b c d 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. ^ a b c d e 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. ^ a b c d 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. American Museum of Natural History Library. New York, NY : American Museum of Natural History.
  9. ^ a b 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. ^ a b 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. ^ a b c d 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. ^ a b Lopatin, Alexey (January 1997). "New Oligocene Didymoconidae (Mesonychia, Mammalia) from Mongolia and Kazakhstan". Paleontological Journal. 31 (1): 108–119.
  13. ^ a b c d e f g h i Lopatin, Alexey (January 2005). "Late Paleogene Erinaceidae (Insectivora, Mammalia) from the Ergilin Dzo locality, Mongolia". Paleontological Journal. 39 (1): 85–92.
  14. ^ a b c d e f g h 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. ^ a b 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. ^ a b c d e f g h i 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:HCATHF]2.0.CO;2. ISSN 0272-4634.
  17. ^ a b 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. ^ a b 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. ^ 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 Dashzeveg, D (1991). "Hyracodontids and rhinocerotids (Mammalia, Perissodactyla, Rhinocerotoidea) from the Paleogene of Mongolia". Palaeovertebrata. 21: 1–84.
  20. ^ a b c d e f g 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:STPABO]2.0.CO;2. ISSN 0003-0090.
  21. ^ a b c d e f g h i j k 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. ^ a b 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.