Abstract:
The evolution of the superfamily Popanocerataceae is studied. The nominotypical family Popanoceratidae includes two subfamilies (Popanoceratinae and Pamiropopanoceratinae). The study of the most recent finds of Roadian ammonoids allowed the establishment of a new stage of active morphogenesis in the family Mongoloceratidae, which includes the new genus Biarmiceras, combining characters connecting the two families of the Popanocerataceae. Five species are described: Biarmiceras tumarense (Ruzhencev), B. subtumarense (Andrianov), B. esaulovae sp. nov., B. kremeshkense sp. nov., and B. barskovi sp. nov. from the Kungurian-Roadian of northeastern Russia and the Kazanian of the Volga-Urals Region. Copyright © 2005 by MAIK "Nauka/Interperiodica" (Russia).