Artinskian


In the geologic timescale, the Artinskian is an age or stage of the Permian. It is a subdivision of the Cisuralian epoch or series. The Artinskian likely lasted between and million years ago according to the most recent revision of the International Commission on Stratigraphy in 2013, though older versions of the ICS preferred a younger age range. It was preceded by the Sakmarian and followed by the Kungurian.

Stratigraphy

The Artinskian is named after the small Russian city of Arti, situated in the southern Ural mountains, about 200 km southwest of Yekaterinburg. The stage was introduced into scientific literature by Alexander Karpinsky in 1874.

Base of the Artinskian

The base of the Artinskian stage is defined as the first appearance datum of the conodont species Sweetognathus whitei and Mesogondolella bisselli. In order to constrain this age, the ICS subcommission on Permian stratigraphy informally proposed a candidate GSSP in 2002, later followed by a formal proposal in 2013. This candidate GSSP is the Dal'ny Tulkas roadcut in the Southern Urals, near the town of Krasnousolsky.
U-Pb radiometric dating found that the base of the Artinskian was approximately 290.1 million years old, based on the position of the rock layer at the Dal'ny Tulkas roadcut containing the FAD of S. whitei relative to three precisely dated ash beds surrounding it. Earlier radiometric reported a much younger age of 280.3 Ma for the Sakmarian-Artinskian boundary.

Top of the Artinskian

The top of the Artinskian is defined as the place in the stratigraphic record where fossils of conodonts Neostreptognathodus pnevi and Neostreptognathodus exculptus first appear.

Artinskian life

Arthropods

Cartilaginous fishes

Ray-finned fishes

Coelacanths

Lungfishes

†Temnospondyls

†Embolomerians

†Seymouriamorphs

†Diadectomorphs

†Mesosaurs

†Procolophonomorphs

Eureptilians

Diapsids

Synapsids