The Cisuralian is the first series/ epoch of the Permian. The Cisuralian was preceded by the

Pennsylvanian Pennsylvanian may refer to: * A person or thing from Pennsylvania * Pennsylvanian (geology) The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, in the International Commission on Stratigraphy, ICS geologic timesca ...

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. The Cisuralian is often synonymous with the informal terms early Permian or lower Permian. It corresponds approximately with the Wolfcampian in southwestern North America. The series saw the appearance of beetles and flies and was a relatively stable warming period of about 21 million years.

Name and background

The Cisuralian is the first series or epoch of the Permian. The Cisuralian was preceded by the last Pennsylvanian epoch ( Gzhelian) and is followed by the Permian Guadalupian Epoch. 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 International Chronostratigraphic Chart (v2018/07) provides a numerical age of 298.9 ± 0.15 – 272.3 ± 0.5 Mya. The base of the Cisuralian series and the Permian

system A system is a group of Interaction, interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment (systems), environment, is described by its boundaries, ...

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.

Geography

Gondwana Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages ...

collided with 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.

Climate

At the start of the Permian, the Late Palaeozoic Ice Age, which began in the

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...

, was at its peak.

Glaciers A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as ...

receded over the course of the late Cisuralian as the Earth's climate gradually warmed, particularly during the Artinskian Warming Event, drying the continent's interiors.Palaeos: Life Through Deep Time > The Permian Period
Accessed 1 April 2013. The pan-tropical belt of Pangaea experienced particularly significant aridification during this epoch.

Biodiversity

The swampy fringes were mostly ferns, seed ferns, and lycophytes. The series saw the appearance of beetles and flies. The coal swamps from the

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

amphibian Amphibians are tetrapod, four-limbed and ectothermic vertebrates of the Class (biology), class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terres ...

s,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. 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. File:Dimetrodon grandis.jpg, ''

Dimetrodon ''Dimetrodon'' ( or ,) meaning "two measures of teeth,” is an extinct genus of non-mammalian synapsid that lived during the Cisuralian (Early Permian), around 295–272 million years ago (Mya). It is a member of the family Sphenacodontid ...

'', a pelycosaur, was at the top of the food chain in the Cisuralian File:Helicoprion bessonovi cropped.png, '' Helicoprion bessonovi'' with characteristic 'tooth-whorl' at front of jaw

Subdivisions

Global

* 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)

Regional

*New Zealand **Telfordian (289 – 278 Mya) **Mangapirian (278 – 270.6 Mya)

References

{{Geological history, p, m Geological epochs *01