Late Devonian plant communities of North Russia

Abstract

The article summarizes researches on the Late Devonian vegetation based on rich palaeobotanical collections from different localities of northern Russia (North Timan). The composition and the structure of the land plant communities are described. Changes in the vegetation are reported during the Frasnian and Famennian. The most diverse palaeovegetation included 29 taxa and occurred in the late Frasnian (Ust'besmozhitsa Formation). It was followed by a floral decrease (6 taxa) in the latest Frasnian (Kamenka Formation). The taxonomic composition of the Famennian vegetation (12 taxa) was much poorer than that of the Frasnian. Differences between the archaeopteridean assemblages of the studied region and the coeval assemblages of the surrounding areas (Russia, Ukraine and Belarus) are discussed. In North Timan, the highest archaeopterid diversity occurred in the Frasnian whereas, in the Donetsk Region of the Ukraine, it occurred in the Famennian.