# Cisuralian By [Rengouku](https://paragraph.com/@rengouku) · 2023-05-30 --- The **Cisuralian** is the first [series](https://en.wikipedia.org/wiki/Series_\(stratigraphy\))/[epoch](https://en.wikipedia.org/wiki/Epoch_\(geology\)) of the [Permian](https://en.wikipedia.org/wiki/Permian). The Cisuralian was preceded by the [Pennsylvanian](https://en.wikipedia.org/wiki/Pennsylvanian_\(geology\)) and followed by the [Guadalupian](https://en.wikipedia.org/wiki/Guadalupian). The Cisuralian Epoch is named after the western slopes of the [Ural Mountains](https://en.wikipedia.org/wiki/Ural_Mountains) in Russia and [Kazakhstan](https://en.wikipedia.org/wiki/Kazakhstan) and dates between 298.9 ± 0.15 – 272.3 ± 0.5 Mya.[\[4\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-a2004-4) The Cisuralian is often synonymous with the informal terms **early Permian** or **lower Permian**. It corresponds approximately with the **Wolfcampian** in southwestern North America.[\[5\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-5)[\[6\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-6) The series saw the appearance of [beetles](https://en.wikipedia.org/wiki/Beetle) and [flies](https://en.wikipedia.org/wiki/Fly) 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.[\[7\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-Chart-7) The Cisuralian was preceded by the last Pennsylvanian epoch ([Gzhelian](https://en.wikipedia.org/wiki/Gzhelian)) and is followed by the Permian [Guadalupian](https://en.wikipedia.org/wiki/Guadalupian) Epoch. The name "Cisuralian" was proposed in 1982,[\[8\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-8) and approved by the International Subcommission on Permian Stratigraphy in 1996.[\[9\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-9) The Cisuralian Epoch is named after the western slopes of the Ural Mountains in Russia and Kazakhstan.[\[10\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-Perm-10)[\[11\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-Paleos-11)[\[12\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-12) Limestones on the edge of [Russian Platform](https://en.wikipedia.org/wiki/Russian_Platform) and make up the [Ishimbay](https://en.wikipedia.org/wiki/Ishimbay) oil fields. These oil fields were vital to the Soviet Union during WW2 when the Germans controlled the oil fields to the west.[\[10\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-Perm-10) The International Chronostratigraphic Chart (v2018/07)[\[7\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-Chart-7) provides a numerical age of 298.9 ± 0.15 – 272.3 ± 0.5 Mya.[\[13\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-13) The base of the Cisuralian series and the Permian [system](https://en.wikipedia.org/wiki/System_\(stratigraphy\)) is defined as the place in the stratigraphic record where fossils of the conodont [_Streptognathodus_](https://en.wikipedia.org/wiki/Streptognathodus) _isolatus_ first appear. The global reference profile for the base (the [GSSP or golden spike](https://en.wikipedia.org/wiki/GSSP)) is located in the valley of the Aidaralash River, near [Aqtöbe](https://en.wikipedia.org/wiki/Aqt%C3%B6be) in the Ural Mountains of Kazakhstan.[\[14\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-14) Geography --------- [Gondwana](https://en.wikipedia.org/wiki/Gondwana) collided with [Laurussia](https://en.wikipedia.org/wiki/Laurussia) and created the [Alleghenian orogeny](https://en.wikipedia.org/wiki/Alleghenian_orogeny) in present-day North America.[\[10\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-Perm-10) In northwestern Europe, the [Hercynian orogeny](https://en.wikipedia.org/wiki/Hercynian_orogeny) continued.[\[10\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-Perm-10) This created the large supercontinent, [Pangea](https://en.wikipedia.org/wiki/Pangea), by the middle of the early Permian, which was to have an impact on the climate.[\[10\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-Perm-10) Climate ------- [Selwyn Rock, South Australia](https://en.wikipedia.org/wiki/Inman_Valley,_South_Australia), an exhumed [glacial pavement](https://en.wikipedia.org/wiki/Glacial_striation) of Permian age At the start of the Permian, the [Late Palaeozoic Ice Age](https://en.wikipedia.org/wiki/Late_Paleozoic_icehouse), which began in the [Carboniferous](https://en.wikipedia.org/wiki/Carboniferous), was at its peak. [Glaciers](https://en.wikipedia.org/wiki/Glacier) receded over the course of the late Cisuralian as the Earth's climate gradually warmed,[\[15\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-ChristopherScotese-15) particularly during the Artinskian Warming Event,[\[16\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-MarchettiEtAl-16) drying the continent's interiors.[\[17\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-MichelEtAl2015-17)[\[18\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-palaeos.com-18)[\[19\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-Grossman2008-19) The pan-tropical belt of Pangaea experienced particularly significant aridification during this epoch.[\[20\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-20)[\[21\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-MujalEtAl2018-21)[\[22\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-22) Biodiversity ------------ The swampy fringes were mostly ferns, seed ferns, and [lycophytes](https://en.wikipedia.org/wiki/Lycophytes). The series saw the appearance of beetles and flies.[\[10\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-Perm-10) The coal swamps from the [Carboniferous](https://en.wikipedia.org/wiki/Carboniferous) continued and the herbivores,\* [Diadectes](https://en.wikipedia.org/wiki/Diadectes) _and_ [_Edaphosaurus_](https://en.wikipedia.org/wiki/Edaphosaurus)_._[_\[11\]_](https://en.wikipedia.org/wiki/Cisuralian#cite_note-Paleos-11) _The dry interior with small insectivores._ [_Caseids_](https://en.wikipedia.org/wiki/Caseids) _and prototherapsid_ [Tetraceratops](https://en.wikipedia.org/wiki/Tetraceratops)\* made their appearance.[\[11\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-Paleos-11) The marine life was probable more diverse than modern times as the climate warmed.[\[10\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-Perm-10) Unusual sharks such as [_Helicoprion_](https://en.wikipedia.org/wiki/Helicoprion) continued in this series. Early Permian terrestrial faunas were dominated by pelycosaurs, [diadectids](https://en.wikipedia.org/wiki/Diadectidae), and [amphibians](https://en.wikipedia.org/wiki/Amphibian),[\[23\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-Huttenlocker,_A._K._2012._Pp._90-23)[\[24\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-24) The pelycosaurs appeared during the [Late Carboniferous](https://en.wikipedia.org/wiki/Pennsylvanian_\(geology\)), and reached their apex in the Cisuralian remaining the dominant land animals for some 40 million years.[\[11\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-Paleos-11)[\[25\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-25) A few continued into the [Capitanian](https://en.wikipedia.org/wiki/Capitanian). They were succeeded by the [therapsids](https://en.wikipedia.org/wiki/Therapsid).[\[11\]](https://en.wikipedia.org/wiki/Cisuralian#cite_note-Paleos-11) --- *Originally published on [Rengouku](https://paragraph.com/@rengouku/cisuralian)*