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.

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Itat Formation
Stratigraphic range: Bajocian-Bathonian ~170–166 Ma PreꞒ Ꞓ O S D C P T J K Pg N ↓
Type	Geological formation
Sub-units	Lower, Middle and Upper members
Underlies	Tyazhin Formation
Overlies	Ilan Formation
Thickness	Several hundred metres
Lithology
Primary	Sandstone, mudstone, coal
Other	Siltstone
Location
Coordinates	55.7°N 89.2°E / 55.7; 89.2
Approximate paleocoordinates	58.2°N 86.7°E / 58.2; 86.7
Region	Siberia
Country	Russia
Extent	Krasnoyarsk krai, Nazarovo depression, SE West Siberian basin
Type section
Named for	Itatsky
Itat Formation (Russia) Show map of Russia Itat Formation (Krasnoyarsk Krai) Show map of Krasnoyarsk Krai

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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]

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.

Taken from^[2] unless otherwise noted.

• List of dinosaur-bearing rock formations