NEW SPECIES OF EARLY PERMIAN BRACHIOPODS AND BIOSTRATIGRAPHY OF THE BOREAL BASIN OF MONGOLIA

Abstract

Three new species of brachiopods-Orthotetes afanasjevae sp. nov., Jakutoproguctus ganelini sp. nov., and Costatumulus sidorkini sp. nov.-are described from the reference section of the Lower Permian deposits of central Mongolia. A new brachiopod zone and a horizon of the zone rank are defined. The age of the enclosing sediments of the Lower Delgerkhan Subformation is established. The benthic fauna of the zone (and corresponding horizon) is listed and correlated with coeval units of southern Mongolia and northeastern Asia.