Itat Formation

The Itat Formation (Russian: итатская свита) is a geologic formation in western Siberia. It was deposited in the Bajocian to Bathonian ages of the Middle Jurassic.[1] Dinosaur remains are among the fossils that have been recovered from the formation, including the proceratosaurid Kileskus, as well as fish, amphibians, mammals and many other vertebrates.[2] The formation is noted for bearing significant coal reserves, with large open pit coal mines extracting lignite from the unit currently in operation.

Itat Formation
Stratigraphic range: Bajocian-Bathonian
~170–166 Ma
↓
TypeGeological formation
Sub-unitsLower, Middle and Upper members
UnderliesTyazhin Formation
OverliesIlan Formation
ThicknessSeveral hundred metres
Lithology
PrimarySandstone, mudstone, coal
OtherSiltstone
Location
Coordinates55.7°N 89.2°E / 55.7; 89.2
Approximate paleocoordinates58.2°N 86.7°E / 58.2; 86.7
RegionSiberia
Country Russia
ExtentKrasnoyarsk krai, Nazarovo depression, SE West Siberian basin
Type section
Named forItatsky
Itat Formation (Russia)
Itat Formation (Kemerovo Oblast)

Lithology

The lower section of the formation is around 50–130 m thick, and consists of light grey sandstones with gravel, siltstone and rare coal beds.[3] At the Dubinino locality, the 50 m exposed section of the upper part of the formation shows an irregular rhythmic alteration of fine grained sandstone, siltstone and mudstone and coal seams typically a few tens of cm's but up to several meters thick.[1] The deposit is located on the South Eastern margin of the West Siberian basin[4]

Locality

Most of the fossils were found in the overburden of Berezovsk coal mine[ru], which is located in southern Krasnoyarsk Krai (Sharypovsky District) near the border with Kemerovo Oblast. The deposit is stratigraphically located in the upper member of the formation. The fossiliferous level of the locality is located above thick (> 50 m) coal seams and consists of unconsolidated silt and sand, which were deposited on an alluvial plain. Due to the fluvial origin of the sediment the remains are disarticulated and often are water worn, though they are mostly well preserved, which suggests they had not been significantly transported.[5] The fossils were largely obtained by screenwashing of the debris. 10-15 tons of material have been processed so far.

Paleobiota

Taken from[2] unless otherwise noted.

Fish
Fish of the Itat Formation
Genus Species Location Stratigraphic position Abundance Notes Images
Hybodus Indeterminate Berezovsk coal mine Upper Member Partial tooth
Acipenseriformes Indeterminate Berezovsk coal mine Upper Member Scales
Amiiformes Indeterminate Berezovsk coal mine Upper Member "Abundant vertebrae, jaws and vomer fragments, as well as isolated teeth, and numerous isolated rhomboidal scales"
Dipnoi Indeterminate Berezovsk coal mine Upper Member One complete upper tooth plate, several tooth plate fragments
Palaeonisciformes Undescribed Berezovsk coal mine Upper Member Many partial skeletons Similar to Palaeoniscinotus and Pteroniscus

Amphibians
Amphibians of the Itat Formation
Genus Species Location Stratigraphic position Abundance Notes Images
?Eodiscoglossus[6] Indeterminate Berezovsk coal mine Upper Member Atlantal centrum Frog
Kiyatriton[7] K. krasnolutskii Berezovsk coal mine Upper Member Dentary, atlantes, trunk vertebrae and fragmentary cranial and postcranial bones Formerly known as "Berezovsk salamander B"; genus also known from Early Cretaceous Ilek Formation. Crown group Salamander
Urupia[8] U. monstrosa Berezovsk coal mine Upper Member Dentary, femur, an incomplete atlas, an anterior fragment of the left dentary, and fragments of trunk vertebrae Estimated length of 480-560 centimetres Stem-Salamander
Egoria [9] E. malashichevi Berezovsk coal mine Upper Member Atlantal centra, trunk vertebrae Formerly known as "Berezovsk salamander A" Possibly neotenic Stem-Salamander

Turtles
Turtles of the Itat Formation
Genus Species Location Stratigraphic position Abundance Notes Images
Annemys[10] Indeterminate Berezovsk coal mine Upper Member Thousands of isolated bones and several fragmented specimens, including three partial braincases and larger fragments of connected shell parts Xinjiangchelyid
Testudines Indeterminate Berezovsk coal mine Upper Member 3 distinct taxa

Lepidosauromorphs
Lepidosauromorphs of the Itat Formation
Genus Species Location Stratigraphic position Abundance Notes Images
Lepidosauromorpha Indeterminate Berezovsk coal mine Upper Member Several fragments of dentaries and maxillae Basal form similar to Marmoretta
Scincomorpha Indeterminate Berezovsk coal mine Upper Member Fused premaxillae and two dentary fragments additionally several fragmentary maxillae and dentaries Two distinct taxa, one of which is two times smaller than the other.

Choristoderes
Choristoderes of the Itat Formation
Genus Species Location Stratigraphic position Abundance Notes Images
Cteniogenys Indeterminate Berezovsk coal mine Upper Member Skull roof bones, maxillary and dentary fragments, vertebrae, ribs

Pterosaurs
Pterosaurs of the Itat Formation
Genus Species Location Stratigraphic position Abundance Notes Images
?Rhamphorhynchidae Indeterminate Berezovsk coal mine Upper Member Numerous isolated teeth and very rare bone fragments

Crocodyliformes
Crocodyliformes of the Itat Formation
Genus Species Location Stratigraphic position Abundance Notes Images
Goniopholididae[11] Indeterminate Berezovsk coal mine Upper Member Several dozens of isolated teeth, osteoderms, and a few cranial fragments

Non-avian dinosaurs
Non Avian DInosaurs of the Itat Formation
Genus Species Location Stratigraphic position Abundance Notes Images
Kileskus[12] K. aristotocus Berezovsk coal mine Upper Member Holotype description: "premaxilla, maxilla, a mandible fragment, and several limb bone parts"; referred material includes cervical and caudal vertebrae and numerous isolated teeth, as well as a fibula[13] Proceratosaurid
Heterodontosauridae Indeterminate Berezovsk coal mine Upper Member Isolated maxillary and dentary teeth
Mamenchisauridae[14] Indeterminate Berezovsk coal mine Upper Member Numerous isolated teeth and two platycoelous posterior caudal vertebrae Sauropod
Stegosauria[15] Indeterminate Berezovsk coal mine Upper Member Fragmentary skeletons of at least two individuals

Tritylodontids
Tritylodontids of the Itat Formation
Genus Species Location Stratigraphic position Abundance Notes Images
Stereognathus[16] Indeterminate Berezovsk coal mine Upper Member Upper and lower postcanine teeth

Mammaliaformes
Mammaliaformes of the Itat Formation
Genus Species Location Stratigraphic position Abundance Notes Images
Amphibetulimus[17] A. krasnolutskii Berezovsk coal mine Upper Member Dentary fragments, canine and upper molar[18]
Amphitherium Indeterminate Berezovsk coal mine Upper Member Upper and lower molars and an edentulous dentary fragment
Anthracolestes[19] A. sergeii Berezovsk coal mine Upper Member Isolated teeth and edentulous dentary fragments Dryolestid
Hutegotherium[20] H. yaomingi Berezovsk coal mine Upper Member Docodontan
Itatodon[21] I. tatarinovi Berezovsk coal mine Upper Member Docodontan
Maiopatagium M. sibiricum[22] Berezovsk coal mine Upper Member Euharamiyida
Sharypovoia[22] S. arimasporum, S. magna Berezovsk coal mine Upper Member Shenshouidae Haramiyidan
Simpsonodon[20] S. sibiricus Berezovsk coal mine Upper Member Docodontan
"Sineleutherus"[23] "S." issedonicus Berezovsk coal mine Upper Member Haramiyidan, now believed to represent a number of different euharamiydan taxa.[22]
Tagaria[5] T. antiqua Berezovsk coal mine Upper Member Isolates premoar and two molars Multituberculate
Tashtykia[5] T. primaeva Berezovsk coal mine Upper Member Isolated premolars and incisors Multituberculate
Eutriconodonta[24] Indeterminate Berezovsk coal mine Upper Member One large tooth and several tooth fragments Large tooth similar to Gobiconodon
Multituberculata Indeterminate Berezovsk coal mine Upper Member Molariforms

Insects

Numerous insect species are known from the Kubekovo village locality located within the upper member of the formation.[25]

Flora
Flora of the Itat Formation[1]
Genus Species Location Stratigraphic position Abundance Notes Images
Lycopodites Indeterminate Club moss
Equisetites E. asiaticus, E. cf. lateralis Stem-horsetail
Coniopteris C. hymenophylloides, C. simplex, C. cf. maakiana Fern
Cladophlebis C. denticulata Fern
Gonatosorus G. cf mrassiensis Fern
Todites T. cf. princeps Fern
Lobifolia Indeterminate Fern
Rhizomopteris Indeterminate Fern
Ginkgo Indeterminate, G. ex gr. insolita Genus extant
Podozamites Indeterminate Gymnosperm
Sphenobaiera Indeterminate Ginkgoales
Stenorachis S. cf. scanicus Gymnosperm
Czekanowskia Indeterminate Ginkgoales

See also
  • List of dinosaur-bearing rock formations

References
  1. Ivantsov, S. V.; Bystritskaya, L. I.; Krasnolutskii, S. A.; Lyalyuk, K. P.; Frolov, A. O.; Alekseev, A. S. (September 2016). "Middle Jurassic continental biota and paleolandscape in the Dubinino locality (Sharypovo area, Krasnoyarsk krai)". Stratigraphy and Geological Correlation. 24 (5): 486–502. doi:10.1134/s0869593816050038. ISSN 0869-5938.
  2. "Middle Jurassic vertebrate assemblage of Berezovsk coal mine in western Siberia (Russia)". Global Geology. 19 (4): 187–204. 2016. doi:10.3969/j.issn.1673-9736.2016.04.01.
  3. "THE ILANSK FORMATION AND ITS STRATOȚYPE". Russian Geology and Geophysics.
  4. Le Heron, Daniel Paul; Buslov, Micha M.; Davies, Clare; Richards, Keith; Safonova, Inna (July 2008). "Evolution of Mesozoic fluvial systems along the SE flank of the West Siberian Basin, Russia". Sedimentary Geology. 208 (1–2): 45–60. doi:10.1016/j.sedgeo.2008.05.001.
  5. Averianov, Alexander O.; Martin, Thomas; Lopatin, Alexey V.; Schultz, Julia A.; Schellhorn, Rico; Krasnolutskii, Sergei; Skutschas, Pavel; Ivantsov, Stepan (2020-04-30). Hautier, Lionel (ed.). "Multituberculate mammals from the Middle Jurassic of Western Siberia, Russia, and the origin of Multituberculata". Papers in Palaeontology: spp2.1317. doi:10.1002/spp2.1317. ISSN 2056-2802.
  6. Skutschas, Pavel P.; Martin, Thomas; Krasnolutskii, Sergei A. (2016-02-24). "First Jurassic frog from Siberia, Russia". Journal of Vertebrate Paleontology. 36 (3): e1101376. doi:10.1080/02724634.2016.1101376. ISSN 0272-4634.
  7. Skutschas, Pavel P. (2015-10-28). "A new crown-group salamander from the Middle Jurassic of Western Siberia, Russia". Palaeobiodiversity and Palaeoenvironments. 96 (1): 41–48. doi:10.1007/s12549-015-0216-x. ISSN 1867-1594.
  8. P. P. Skutschas & S. A. Krasnolutskii (2011). "A new genus and species of basal salamanders from the Middle Jurassic of western Siberia, Russia" (PDF). Proceedings of the Zoological Institute RAS. 315 (2): 167–175.
  9. Skutschas, Pavel; Kolchanov, Veniamin; Krasnolutskii, Sergey; Averianov, Alexander; Schellhorn, Rico; Schultz, Julia; Martin, Thomas (2020-02-19). Porro, Laura Beatriz (ed.). "A new small-sized stem salamander from the Middle Jurassic of Western Siberia, Russia". PLOS ONE. 15 (2): e0228610. doi:10.1371/journal.pone.0228610. ISSN 1932-6203.
  10. Danilov, I. G.; Obraztsova, E. M.; Boitsova, E. A.; Skutschas, P. P. (March 2018). "Diversity of Middle Jurassic Turtles from the Berezovsk Quarry Locality, Krasnoyarsk Region, Russia: Morphology and Histological Study". Paleontological Journal. 52 (2): 188–200. doi:10.1134/s0031030118010070. ISSN 0031-0301.
  11. Kuzmin, I.T.; Skutschas, P.P.; Grigorieva, O.I.; Krasnolutskii, S.A. (2013). "Goniopholidid crocodylomorph from the Middle Jurassic Berezovsk Quarry locality ( Western Siberia, Russia)". Proceedings of the Zoological Institute of the Russian Academy of Sciences. 317 (4): 452–458.
  12. Averianov, A. O.; Krasnolutskii, S. A.; Ivantsov, S. V. (2010). "A new basal coelurosaur (Dinosauria: Theropoda) from the Middle Jurassic of Siberia". Proceedings of the Zoological Institute. 314 (1): 42–57.
  13. O. Averianov, Alexander; Osochnikova, Anastasia; Skutschas, Pavel; Krasnolutskii, Sergei; Schellhorn, Rico; A. Schultz, Julia; Martin, Thomas (2019-09-16). "New data on the tyrannosauroid dinosaur Kileskus from the Middle Jurassic of Siberia, Russia". Historical Biology: 1–7. doi:10.1080/08912963.2019.1666839. ISSN 0891-2963.
  14. Averianov, Alexander; Krasnolutskii, Sergei; Ivantsov, Stepan; Skutschas, Pavel; Schellhorn, Rico; Schultz, Julia; Martin, Thomas (2019-03-01). "Sauropod remains from the Middle Jurassic Itat Formation of West Siberia, Russia". PalZ. 93 (4): 691–701. doi:10.1007/s12542-018-00445-8. ISSN 0031-0220.
  15. Averianov, A.O.; Krasnolutskii, S.A. (2009). "Stegosaur remains from the Middle Jurassic of West Siberia". Proceedings of the Zoological Institute RAS. 313 (2): 153–167.
  16. Averianov, Alexander O.; Martin, Thomas; Lopatin, Alexey V.; Schultz, Julia A.; Skutschas, Pavel P.; Rico, Schellhorn; Krasnolutskii, Sergei A. (2017-09-03). "A tritylodontid synapsid from the Middle Jurassic of Siberia and the taxonomy of derived tritylodontids". Journal of Vertebrate Paleontology. 37 (5): e1363767. doi:10.1080/02724634.2017.1363767. ISSN 0272-4634.
  17. Lopatin, A. V.; Averianov, A. O. (December 2007). "The earliest Asiatic pretribosphenic mammal (Cladotheria, Amphitheriidae) from the Middle Jurassic of Siberia". Doklady Biological Sciences. 417 (1): 432–434. doi:10.1134/s0012496607060063. ISSN 0012-4966.
  18. Averianov, Alexander; Martin, Thomas; Lopatin, Alexey; Krasnolutskii, Sergei (2013-12-22). "Stem therian mammal Amphibetulimus from the Middle Jurassic of Siberia". Paläontologische Zeitschrift. 89 (2): 197–206. doi:10.1007/s12542-013-0217-x. ISSN 0031-0220.
  19. Averianov, Alexander O.; Martin, Thomas; Lopatin, Alexey (2014-06-07). "The oldest dryolestid mammal from the Middle Jurassic of Siberia". Journal of Vertebrate Paleontology. 34 (4): 924–931. doi:10.1080/02724634.2014.837471. ISSN 0272-4634.
  20. Averianov, A. A.; Lopatin, A. V.; Krasnolutskii, S. A.; and Ivantsov, S. V. (2010). "New docodontians from the Middle Jurassic of Siberia and reanalysis of docodonta interrelationships" (PDF). Proceedings of the Zoological Institute RAS. 314 (2): 121–148.CS1 maint: uses authors parameter (link)
  21. Lopatin, A. V.; Averianov, A. O. (November 2005). "A New Docodont (Docodonta, Mammalia) from the Middle Jurassic of Siberia". Doklady Biological Sciences. 405 (1–6): 434–436. doi:10.1007/s10630-005-0158-y. ISSN 0012-4966. PMID 16485637.
  22. Averianov, Alexander O.; Martin, Thomas; Lopatin, Alexey V.; Schultz, Julia A.; Schellhorn, Rico; Krasnolutskii, Sergei; Skutschas, Pavel; Ivantsov, Stepan (2019-11-05). "Haramiyidan mammals from the Middle Jurassic of Western Siberia, Russia. Part 1: Shenshouidae and Maiopatagium". Journal of Vertebrate Paleontology. 39: e1669159. doi:10.1080/02724634.2019.1669159. ISSN 0272-4634.
  23. A. O. Averianov, A. V. Lopatin and S. A. Krasnolutskii (2011). "The first Haramiyid (Mammalia, Allotheria) from the Jurassic of Russia". Doklady Biological Sciences. 437 (1): 103–106. doi:10.1134/S0012496611020074. PMID 21562957.
  24. Averianov, A. O.; Lopatin, A. V.; Krasnolutskii, S. A. (2008). "An amphilestid grade eutriconodontan from the Middle Jurassic of Russia". Russian Journal of Theriology. 7 (1): 1–4. doi:10.15298/rusjtheriol.07.1.01.
  25. "Kubekovo village (PIN collection 1255)". Paleobiology Database.
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