Moscovian (Carboniferous)


The Moscovian is in the ICS geologic timescale a stage or age in the Pennsylvanian, the youngest subsystem of the Carboniferous. The Moscovian age lasted from to Ma, is preceded by the Bashkirian and is followed by the Kasimovian. The Moscovian overlaps with the European regional Westphalian stage and the North American Atokan and Desmoinesian stages.

Name and definition

The Moscovian stage was introduced by Sergei Nikitin in 1890, using brachiopods in the Moscow Basin of European Russia. Nikitin named the stage after Moscow, then a major city and now the capital of Russia.
The base of the Moscovian is close to the first appearances of the conodonts Declinognathodus donetzianus and Idiognathoides postsulcatus or otherwise the fusulinid Aljutovella aljutovica. Because the fusulinid species are regionally different, they can not be used for worldwide correlation. A golden spike for the Moscovian stage has yet to be defined. A proposal is to use the first appearance of the conodont Diplognathodus ellesmerensis, but since the species is rare and its evolution relatively unknown, it has not been accepted yet.
The top of the Moscovian is at the base of the fusulinid biozone of Obsoletes obsoletes and Protriticites pseudomontiparus, or with the first appearance of the ammonite genus Parashumardites.

Subdivisions

In European Russia and Eastern Europe, where the stage was first recognized, the Moscovian is subdivided into four regional substages: Vereiskian, Kashirskian, Podolskian, and Myachkovskian, named after towns near Moscow.
The Moscovian can biostratigraphically be divided into five conodont biozones:

Arthropods

Jawless fishes

Cartilaginous fishes

Amphibians

Tetrapodomorphs

†Temnospondyls

†Lepospondyls

Reptiliomorphs

Synapsids