PYRAMIDAL SPIRIFERIDS (BRACHIOPODS) FROM THE MIDDLE AND UPPER DEVONIAN OF THE RUSSIAN PLATE: MORPHOLOGY, SYSTEMATICS, AND SHELL WALL STRUCTURE

Abstract

The pyramidal spiriferids Thomasaria Stainbrook, 1945 and Pyramina Ljaschenko, 1969 from the collection of brachiopods of Ljaschenko are examined. New data on the shell microornamentation and inner structure support the validity of the genus Piramina and its type species P. oskolensis Ljaschenko. A new species of the genus Thomasaria, T. rotunda is described. © Pleiades Publishing, Inc. 2006.