Bakhar Formation

Bakhar Formation Stratigraphic range: Aalenian-Bathonian ~174–166 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Lithology
Primary	Claystone
Other	Coal
Location
Coordinates	44°54′N 100°54′E / 44.9°N 100.9°E / 44.9; 100.9Coordinates: 44°54′N 100°54′E / 44.9°N 100.9°E / 44.9; 100.9
Approximate paleocoordinates	48°06′N 105°12′E / 48.1°N 105.2°E / 48.1; 105.2
Country	Mongolia
Extent
Bakhar Formation (Mongolia)

The Bakhar Formation (Russian: Bakhar Svita) is a geological formation in Mongolia whose strata date back to the Aalenian to Bathonian stages of the Middle Jurassic, comprising claystones deposited in a lacustrine environment.^[1]

Fossil content[]

Insects; ,^[2] , A. net, A. nym, , B. bacharensis, B. flamma, B. mikro, B. mini, B. universala, B. velika, B. vulgara, , , , H. bavi, H. nie, , , , , P. tatosanerata, P. vana, , , R. krajka, , R. konserva, R. sisnerahkab, , ,^[3] fish (Palaeonisciformes) and pterosaur remains of the family Anurognathidae have been recovered from the formation.^[4][5] The formation has also provided many fossil flora in its coal layers, known as the Tsagan-Ovoo Flora containing 32 megafossil plant taxa belonging to horsetails, ferns, cycadaleans, ginkgoaleans, leptostrobaleans, conifers and gymnosperms. Three new species were named; , and .^[6]

See also[]

• List of pterosaur-bearing stratigraphic units
• Balabansai Formation, contemporaneous fossiliferous formation of Central Asia
• Itat Formation, contemporaneous fossiliferous formation of Russia
• Ukureyskaya Formation, contemporaneous fossiliferous formation of Russia
• Tiaojishan Formation, contemporaneous fossiliferous formation of China

References[]

Bibliography[]

• Vršanský, Peter. 2020. New assemblages of the Bakhar locality. Cockroaches from Jurassic sediments of the Bakhar Formation in Mongolia, 33–62. Springer. doi:10.1007/978-3-030-59407-7_4 ISBN 978-3-030-59406-0
• Kostina, Elena I.; Alexei B. Herman, and Tatiana M. Kodrul. 2015. Early Middle Jurassic (possibly Aalenian) Tsagan-Ovoo Flora of Central Mongolia. Review of Palaeobotany and Palynology 220. 44–68. Accessed 2020-07-09.
• Barrett, P.M.; R.J. Butler; N.P. Edwards, and A.R. Milner. 2008. Pterosaur distribution in time and space: an atlas in Flugsaurier: Pterosaur papers in honour of Peter Wellnhofer. 28. 61–107.
• Bakhurina, N.N., and D.M. Unwin. 1995. A survey of pterosaurs from the Jurassic and Cretaceous of the former Soviet Union and Mongolia. Historical Biology 10. 197–245.
• Sinitshenkova, N.D. 1987. Istopicheskoe razvitie vesiyanok. Akademiya Nauk SSSR, Trudy Paleontologicheskogo Instituta 221. 1–142.