Bashkirian

The Bashkirian is in the ICS geologic timescale the lowest stage or oldest age of the Pennsylvanian. The Bashkirian age lasted from 323.2 to 315.2 Ma,[2] is preceded by the Serpukhovian and is followed by the Moscovian.

This article is about the stage of the Carboniferous. For the defunct Russian airline, see BAL Bashkirian Airlines.
System Subsystem/
Series		 Stage Age (Ma)
Permian Cisuralian Asselian younger
Carboniferous Pennsylvanian Gzhelian 298.9 303.7
Kasimovian 303.7 307.0
Moscovian 307.0 315.2
Bashkirian 315.2 323.2
Mississippian Serpukhovian 323.2 330.9
Visean 330.9 346.7
Tournaisian 346.7 358.9
Devonian Late Famennian older
Subdivision of the Carboniferous system
according to the ICS, as of 2017.[1]

The Bashkirian overlaps with the upper part of the Namurian and lower part of the Westphalian stages from regional European stratigraphy. It also overlaps with the North American Morrowan and Atokan stages and the Chinese Luosuan and lower Huashibanian stages.[3]

Name and definition

The Bashkirian was named after Bashkiria, the then Russian name of the republic of Bashkortostan in the southern Ural Mountains of Russia, home of the Bashkir people. The stage was introduced by Russian stratigrapher Sofia Semikhatova in 1934.

The base of the Bashkirian is at the first appearance of conodont species Declinognathodus noduliferus. The top of the stage (the base of the Moscovian) is at the first appearance of the conodonts Declinognathodus donetzianus or Idiognathoides postsulcatus,[4] or at the first appearance of fusulinid Aljutovella aljutovica.[5] The GSSP (type location for the base of a stage) for the Bashkirian is in the Battleship Wash Formation at Arrow Canyon, Nevada.[6]

Subdivision

The Bashkirian contains six biozones based on conodont index fossils:

  • Neognathodus atokaensis Zone
  • Declinognathodus marginodosus Zone
  • Idiognathodus sinuosus Zone
  • Neognathodus askynensis Zone
  • Idiognathoides sinuatus Zone
  • Declinognathodus noduliferus Zone

Bashkirian life

Arthropods
Arthropoda of the Bashkirian
Taxa Presence Location Description Images
Pennsylvanian Scotland and northeastern North America A 2 m (6.6 ft) long millipede
Arthropleura

Cartilaginous fishes
Chondrichthyes of the Bashkirian
Taxa Presence Location Description Images
Carboniferous to Cisuralian Belgium A eugeneodontid holocephalian
Campodus
Edestus
Xenacanthus
  • Denaea
 Pennsylvanian Kentucky, Ohio, Nebraska, Oklahoma, United States A symmoriid holocephalian
Carboniferous to Cisuralian England A eugeneodontid holocephalian
Carboniferous to Lopingian Ohio, Illinois, United States; England a petalodontiform holocephalian
  • Hagenoselache
 Carboniferous to Cisuralian Germany A xenacanthidan elasmobranch
Carboniferous to Cisuralian Scotland, Wales, Ireland A xenacanthidan elasmobranch

Coelacanths
Actinistia of the Bashkirian
Taxa Presence Location Description Images
Bear Gulch Limestone, Montana, USA A genus of actinistian fish in the family Hadronectoridae, distant relatives to coelacanths.
Allenypterus

Amphibians


Tetrapodomorphs
Tetrapodomorphs of the Bashkirian
Taxa Presence Location Description Images
British Isles A genus of basal amphibians in the family Baphetidae.
Megalocephalus

Temnospondyls
Temnospondyli of the Bashkirian
Taxa Presence Location Description Images
Nova Scotia, Canada;

Jarrow coal mines, Ireland

 Dendrerpeton is a genus of temnospondyl amphibians.
Dendrerpeton
Jarrow coal mines, Ireland A genus of edopoid temnospondyl within the family Cochleosauridae.

Reptiliomorphs
Reptiliomorpha of the Bashkirian
Taxa Presence Location Description Images
Rhein-Ruhr-District, West-Germany Bruktererpeton is a genus of gephyrostegid reptiliomorph.
Bruktererpeton

Eureptiles
Eureptilia of the Bashkirian
Taxa Presence Location Description Images
Pennsylvanian Nova Scotia, Canada A romeriid
Hylonomus

Synapsids
Synapsida of the Bashkirian
Taxa Presence Location Description Images
Nova Scotia, Canada The oldest known synapsid.
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References
  1. http://www.stratigraphy.org/index.php/ics-chart-timescale
  2. Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
  3. Heckel, P.H. & Clayton, G.; 2006: The Carboniferous system, use of the new official names for the subsystems, series and stages, Geologica Acta 4(3), pp 403–407.
  4. Nemyrovska, T.I.; 1999: Bashkirian conodonts of the Donets Basin, Ukraine. Scr. Geol. 119, pp 1–115 (in Russian).
  5. Solovieva, M.N.; 1986: Zonal fusulinid scale of the Moscovian Stage based on a revision of the type sections of intrastage subdivisions, Vopr. Mikropaleontol. 28, pp 3–23 (in Russian).
  6. Lane, H.R.; Brenckle, P.L.; Baesemann, J.F. & Richards, B.; 1999: The IUGS boundary in the middle of the Carboniferous: Arrow Canyon, Nevada, USA, Episodes 22(4), pp 272–283.

Literature
  • Menning, M.; Alekseev, A.S.; Chuvashov, B.I.; Davydov, V.I.; Devuyst, F.-X.; Forke, H.C.; Grunt, T.A.; Hance, L.; Heckel, P.H.; Izokh, N.G.; Jin, Y.-G.; Jones, P.J.; Kotlyar, G.V.; Kozur, H.W.; Nemyrovska, T.I.; Schneider, J.W.; Wang, X.-D.; Weddige, K.; Weyer, D. & Work, D.M.; 2006: Global time scale and regional stratigraphic reference scales of Central and West Europe, East Europe, Tethys, South China, and North America as used in the Devonian–Carboniferous–Permian Correlation Chart 2003 (DCP 2003), Palaeogeography, Palaeoclimatology, Palaeoecology 240(1-2): pp 318–372.

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