| Sakmarian | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 293.52 ± 0.17 – 290.1 ± 0.26Ma | |||||||||||||
| Chronology | |||||||||||||
| |||||||||||||
| Etymology | |||||||||||||
| Name formality | Formal | ||||||||||||
| Usage information | |||||||||||||
| Celestial body | Earth | ||||||||||||
| Regional usage | Global (ICS) | ||||||||||||
| Time scale(s) used | ICS Time Scale | ||||||||||||
| Definition | |||||||||||||
| Chronological unit | Age | ||||||||||||
| Stratigraphic unit | Stage | ||||||||||||
| Time span formality | Formal | ||||||||||||
| Lower boundary definition | FAD of theConodontMesogondolella monstra | ||||||||||||
| Lower boundary GSSP | Usolka section, SouthernUral Mountains,Russia 53°55′29″N56°43′43″E / 53.9247°N 56.7287°E /53.9247; 56.7287 | ||||||||||||
| Lower GSSP ratified | 2018[2] | ||||||||||||
| Upper boundary definition | FAD of theConodontSweetognathus whitei | ||||||||||||
| Upper boundary GSSP | Dalny Tulkas section,Southern Ural Mountains,Russia 53°55′29″N56°30′58″E / 53.9247°N 56.51615°E /53.9247; 56.51615 | ||||||||||||
| Upper GSSP ratified | February 2022[3] | ||||||||||||
In thegeologic timescale, theSakmarian is anage orstage of thePermian period. It is a subdivision of theCisuralianEpoch orSeries. The Sakmarian lasted between 293.52 and 290.1million years ago (Ma). It was preceded by theAsselian and followed by theArtinskian.[4]
The Sakmarian Stage is named after theSakmara River in theUral Mountains, atributary to theUral River. The stage was introduced into scientific literature byAlexander Karpinsky in 1874. In Russianstratigraphy, it originally formed a substage of theArtinskian Stage. Currently, theICS (International Commission on Stratigraphy) uses it as an independent stage in its international geologic timescale.
The base of the Sakmarian Stage is defined by the first appearance of conodont speciesStreptognathodus postfusus in the fossil record. A global reference profile for the stage's base (aGSSP), located in the southern Ural Mountains, Russia, was ratified in 2018. The top of the Sakmarian (the base of the Artinskian) is defined as the level in the stratigraphic record where fossils of conodont speciesSweetognathus whitei andMesogondolella bisselli first appear.
