The Bakhar Formation (Russian: Bakhar Svita) is a geological

formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondary ...

in Mongolia whose strata date back to the

Aalenian The Aalenian () is a subdivision of the Middle Jurassic Epoch/Series of the geologic timescale that extends from about 174.7 ±0.8 Ma to about 170.9 ±0.8 Ma (million years ago). It was preceded by the Toarcian and succeeded by the Bajocian. St ...

Bathonian In the geologic timescale the Bathonian is an age (geology), age and stage (stratigraphy), stage of the Middle Jurassic. It lasted from approximately 168.2 ±1.2 annum, Ma to around 165.3 ±1.1 Ma (million years ago). The Bathonian Age succeeds ...

stages of the

Middle Jurassic The Middle Jurassic is the second Epoch (geology), epoch of the Jurassic Period (geology), Period. It lasted from about 174.1 to 161.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relativel ...

, comprising

claystone Mudrocks are a class of fine-grained siliciclastic sedimentary rocks. The varying types of mudrocks include siltstone, claystone, mudstone and shale. Most of the particles of which the stone is composed are less than and are too small to ...

s deposited in a

lacustrine A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from t ...

environment.Bakhar Formation
at

Fossilworks Fossilworks was a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cr ...

.org

Fossil content

Insects; '' Platyperla propera'',Sinitshenkova, 1987 '' 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'',Vršanský, 2020 fish (

Palaeonisciformes The Palaeonisciformes, commonly known as "palaeoniscoids" (also spelled "paleoniscoid", or alternatively "paleoniscids") are an extinct grouping of primitive ray-finned fish (Actinopterygii), spanning from the Silurian/Devonian to the Cretaceous. ...

) and

pterosaur Pterosaurs are an extinct clade of flying reptiles in the order Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 million to 66 million years ago). Pterosaurs are the earli ...

remains of the family

Anurognathidae Anurognathidae is a family of small, short-tailed pterosaurs that lived in Europe, Asia, and possibly North America during the Jurassic and Cretaceous periods. Eight genera are definitively known: '' Anurognathus'', from the Late Jurassic of Germ ...

have been recovered from the formation.Bakhurina & Unwin, 1995Barret et al., 2008 The formation has also provided many fossil flora in its

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal i ...

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''.Kostina et al., 2015

References

Bibliography

* * * * * {{citation , last=Sinitshenkova , first=N.D , year=1987 , title=Istopicheskoe razvitie vesiyanok , journal=Akademiya Nauk SSSR, Trudy Paleontologicheskogo Instituta , volume=221 , pages=1–142 Geologic formations of Mongolia Jurassic System of Asia Jurassic Mongolia Aalenian Stage Bajocian Stage Bathonian Stage Shale formations Coal formations Coal in Mongolia Lacustrine deposits Paleontology in Mongolia

Fossil content

See also

References

Bibliography