The Itat Formation (Russian: итатская свита) is a geologic formation in western Siberia. It was deposited in the Bajocian to Bathonianages 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 pitcoal mines extracting lignite from the unit currently in operation.
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.
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[14]
^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. Bibcode:2016SGC....24..486I. doi:10.1134/s0869593816050038. ISSN 0869-5938. S2CID 131891128
^Averianov AO, Martin T, Skutschas PP, Danilov IG, Schultz JA, Schellhorn R, et al. (2016). "Middle Jurassic vertebrate assemblage of Berezovsk coal mine in western Siberia (Russia)". Global Geology. 19 (4): 187–204. doi:10.3969/j.issn.1673-9736.2016.04.01
^"THE ILANSK FORMATION AND ITS STRATOȚYPE". Russian Geology and Geophysics
^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. S2CID 131522274
^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. S2CID 90021437
^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. doi:10.31610/trudyzin/2010.314.1.42. S2CID 53491764
^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. 33 (7): 897–903. doi:10.1080/08912963.2019.1666839. ISSN 0891-2963. S2CID 203890300
^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. S2CID 135205021
^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. PMID 18274483. S2CID 1198624
^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. S2CID 132581198
^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. S2CID 85070390
^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 (4). doi:10.1080/02724634.2019.1669159. ISSN 0272-4634. S2CID 209439988
^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. S2CID 31481732
^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). doi:10.1080/02724634.2017.1363767. ISSN 0272-4634. S2CID 90249441