Download PDF

STRATIGRAPHIC DISTRIBUTION OF RHYNCHONELLIFORMEA BRACHIOPODS IN THE CAMBRIAN OF THE SIBERIAN PLATFORM

D. А. Ilyin 1, I. V. Korovnikov 1,2

1 Novosibirsk State University, Novosibirsk, Russia; 2 Trofimuk Institute of Petroleum Geology and Geophysics SB RAS, Novosibirsk, Russia​

Results of the analysis of the stratigraphic distribution of Rhynchonelliform brachiopods (subphylum Rhynchonelliformea) have shown this group to be present in the sections of the southeastern, northeastern, and northwestern parts of the Siberian Platform and of the Anabar region. The Lower Cambrian is represented mainly by different genera within two classes Oboleata and Kutorginata. In the Middle Cambrian, brachiopods of the subphylum Rhynchonelliformea almost completely disappeared from the sections of the regions where they were extant in the Lower Cambrian. Rare finds of Kutorgina, Nisusia, Matutella are known from the lowermost Middle Cambrian, and those of Strophomenata from the Ayusokkanian stage, but strictly in the northwest of the Siberian Platform (solitary genus Billingusella). In the Sakian stage of the Upper Cambrian, both the abundance and diversity of the Strophomenata brachiopods tend to decline. New Rhynchonellata representatives appearing in the Aksayan stage (Upper Cambrian), are present in the Aksayan and Batyrbayan stages of the Upper Cambrian in the northwest of the Siberian Platform.

Keywords: Cambrian, Rhynchonelliformea brachiopods, Siberian platform.

DOI 10.20403/2078-0575-2025-3-17-27

​ ​​​​​​​​​​