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′N100°54′E / 44.9°N 100.9°E / 44.9; 100.9
Approximate paleocoordinates	48°06′N105°12′E / 48.1°N 105.2°E / 48.1; 105.2
Country	Mongolia
Extent	North Molasse Basin
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; Platyperla propera , ^[2] Ano da , A. net, A. nym, Blattula anuniversala , B. bacharensis, B. flamma, B. mikro, B. mini, B. universala, B. velika, B. vulgara, Caloblattina vremeni , Dostavba pre , Hra disko , H. bavi, H. nie, Nuurcala cela , Okras sarko , Perlucipecta cosmopolitana , Polliciblattula analis , P. tatosanerata, P. vana, Praeblattella jurassica , Raphidiomima chimnata , R. krajka, Rhipidoblattina bakharensis , R. konserva, R. sisnerahkab, Solemnia togokhudukhensis , Truhla vekov , ^[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; Ginkgo badamgaravii , Pseudotorellia gobiense and P. mongolica . ^[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

1. Bakhar Formation at Fossilworks.org
2. Sinitshenkova, 1987
3. Vršanský, 2020
4. Bakhurina & Unwin, 1995
5. Barret et al., 2008
6. Kostina et al., 2015

Bibliography

• Vršanský, Peter (2020), "New assemblages of the Bakhar locality", in Peter Vršanský (ed.), Cockroaches from Jurassic sediments of the Bakhar Formation in Mongolia, SpringerBriefs in Animal Sciences, Springer, pp. 33–62, doi:10.1007/978-3-030-59407-7_4, ISBN   978-3-030-59406-0
• Kostina, Elena I.; Herman, Alexei B.; Kodrul, Tatiana M. (2015), "Early Middle Jurassic (possibly Aalenian) Tsagan-Ovoo Flora of Central Mongolia", Review of Palaeobotany and Palynology , 220: 44–68, Bibcode:2015RPaPa.220...44K, doi:10.1016/j.revpalbo.2015.04.010 , retrieved 2020-07-09
• Barrett, P.M.; Butler, R.J.; Edwards, N.P.; Milner, A.R. (2008), "Pterosaur distribution in time and space: an atlas in Flugsaurier: Pterosaur papers in honour of Peter Wellnhofer" (PDF), Zitteliana B , 28: 61–107
• Bakhurina, N.N.; Unwin, D.M. (1995), "A survey of pterosaurs from the Jurassic and Cretaceous of the former Soviet Union and Mongolia", Historical Biology , 10 (3): 197–245, Bibcode:1995HBio...10..197B, doi:10.1080/10292389509380522
• Sinitshenkova, N.D (1987), "Istopicheskoe razvitie vesiyanok", Akademiya Nauk SSSR, Trudy Paleontologicheskogo Instituta, 221: 1–142