|298.9 ± 0.15 – 273.01 ± 0.14 Ma|
The world at the start of the Cisuralian
|Regional usage||Global (ICS)|
|Time scale(s) used||ICS Time Scale|
|Time span formality||Formal|
|Lower boundary definition||FAD of the conodont Streptognathodus isolatus within the morphotype Streptognathodus wabaunsensis chronocline|
|Lower boundary GSSP||Aidaralash, Ural Mountains, Kazakhstan|
|Upper boundary definition||FAD of the Conodont Jinogondolella nanginkensis|
|Upper boundary GSSP||Stratotype Canyon, Guadalupe Mountains, Texas , United States|
The Cisuralian is the first series/epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the western slopes of the Ural Mountains in Russia and Kazakhstan and dates between 298.9 ± 0.15 – 272.3 ± 0.5 Mya.
Name and background
The name "Cisuralian" was proposed in 1982, and approved by the International Subcommission on Permian Stratigraphy in 1996. The Cisuralian Epoch is named after the western slopes of the Ural Mountains in Russia and Kazakhstan.
Limestones on the edge of Russian Platform and make up the Ishimbay oil fields. These oil fields were vital to the Soviet Union during WW2 when the Germans controlled the oil fields to the west.
The base of the Cisuralian series and the Permian system is defined as the place in the stratigraphic record where fossils of the conodont Streptognathodus isolatus first appear. The global reference profile for the base (the GSSP or golden spike) is located in the valley of the Aidaralash River, near Aqtöbe in the Ural Mountains of Kazakhstan.
Gondwana collided Laurussia and created the Alleghenian orogeny in present-day North America. In northwestern Europe, the Hercynian orogeny continued. This created the large supercontinent, Pangea, by the middle of the early Permian, which was to have an impact on the climate.
At the start of the Permian, the Earth was still in an ice age, which began in the Carboniferous. Glaciers receded around the mid-Permian period as the climate gradually warmed, drying the continent's interiors.
The swampy fringes were mostly ferns, seed ferns, and lycophytes. The series saw the appearance of beetles and flies.
The coal swamps from the Carboniferous continued and the herbivores, Diadectes and Edaphosaurus. The dry interior with small insectivores. Caseids and prototherapsid Tetraceratops made their appearance. The marine life was probable more diverse than modern times as the climate warmed. Unusual sharks such as Helicoprion continued in this series.
Early Permian terrestrial faunas were dominated by pelycosaurs, diadectids, and amphibians, The pelycosaurs appeared during the Late Carboniferous, and reached their apex in the Cisuralian remaining the dominant land animals for some 40 million years. A few continued into the Capitanian. They were succeeded by the therapsids.
Helicoprion bessonovi with characteristic 'tooth-whorl' at front of jaw
- Asselian stage (298.9 ± 0.15 – 294.6 ± 0.8 Mya)
- Sakmarian stage (294.6 ± 0.8 – 290.1 ± 0.7 Mya)
- Artinskian stage (290.1 ± 0.7 – 283.5 ± 0.7 Mya)
- Kungurian stage (283.5 ± 0.7 – 272.3 ± 0.5 Mya)
- New Zealand
- Telfordian (289 – 278 Mya)
- Mangapirian (278 – 270.6 Mya)
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- International Commission on Stratigraphy. "GSSPs". http://www.stratigraphy.org/index.php/ics-gssps.
- Davydov, V.I.; Glenister, B.F.; Spinosa, C.; Ritter, S.M.; Chernykh, V.V.; Wardlaw, B.R. and Snyder, W.S.; 1998: Proposal of Aidaralash as Global Stratotype Section and Point (GSSP) for base of the Permian System, Episodes 21(1): pp 11–18.
- Palaeos: Life Through Deep Time > The Permian Period Accessed 1 April 2013.
- Huttenlocker, A. K., and E. Rega. 2012. The Paleobiology and Bone Microstructure of Pelycosaurian-grade Synapsids. Pp. 90–119 in A. Chinsamy (ed.) Forerunners of Mammals: Radiation, Histology, Biology. Indiana University Press.
- "NAPC Abstracts, Sto – Tw". berkeley.edu. http://www.ucmp.berkeley.edu/napc/abs23.html#SumidaS.
Original source: https://en.wikipedia.org/wiki/Cisuralian. Read more