Asselian and Sakmarian (Lower Permian) Radiolarian Ecozones of the South Urals (Russia)

• Published in: Paleontological journal Vol. 55; no. 8; pp. 825 - 862
• Main Author: Afanasieva, M. S.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.12.2021; Springer Nature B.V
• Subjects: Distribution; Distribution patterns; Earth and Environmental Science; Earth Sciences; Genera; Geographical distribution; Indigenous species; Paleontology; Permian; Radiolaria; Rivers; Species; Taxonomic revision; ecozones; Kondurovka and Verkhneozernoe sections; radiolarians; Asselian and Sakmarian stages; South Urals; Lower Permian; Russia
• ISSN: 0031-0301; 1555-6174
• DOI: 10.1134/S0031030121080025

A study of Lower Permian radiolarians from the Kondurovka and Verkhneozernoe sections, located on the right bank of the Sakmara and Ural rivers on the western slope of the South Urals, was carried out. Analysis of the distribution of 104 species of radiolarians in the study area made it possible to establish three successive ecozones in the Kondurovka section: (1) Asselian Tetragregnon sphaericus-Latentifistula heteroextrema corresponding to the Streptognathodus postfusus–St. barskovi conodont zone , (2) Sakmarian Arcoclathrata alekseevi–Apophysisphaera sakmaraensis , and (3) Sakmarian Holdsworthella perforata–Helioentactinia ikka corresponding to the Sweetognathus merrilli and Sweetognathus binodosus conodont zones, respectively. The Kozurispongus permicus ecozone was recognized in the Verkhneozernoe section where it corresponds to the Sweetognathus binodosus conodont zone. The taxonomic position of 30 species from 12 genera identified by Kozur (1980, 1981) and Kozur and Mostler (1989) has been revised, which currently belong to 19 genera from four classes of radiolarians. The distribution patterns of Lower Permian radiolarians in the Kondurovka and Verkhneozernoe sections of the South Urals are analyzed. Special attention is paid to indigenous and migrant species.