The distribution and classification of the family Paragastrioceratidae Ruzhencev are briefly discussed. In the subfamily Paragastrioceratinae, P. sterlitamakense Gerassimov, the most basal species of the genus Paragastrioceras Tchernow, is described in detail. Based on morphological analysis, the subfamily Pseudogastrioceratinae is revised, and the Sakmarian species “Stenolobulites” admiralensis (Plummer et Scott, 1937) and “Stenolobites” subglobosus Mikesh, Glenister et Furnish, 1988 are transferred from the genus Stenolobulites Mikesh, Glenister et Furnish to a new genus Parasianites gen. nov., type species P. admiralensis. Also, a new generic name Pseudosvetlanoceras is established to accommodate “Svetlanoceras” moylei Mikesh, as its characteristics do not match the diagnosis of the genus Svetlanoceras. A revised phylogenetic scheme is proposed for the family Paragastrioceratidae.
T. B. Leonova (Sun,) studied this question.