Evolution of the early Permian family Paragastrioceratidae (Ammonoidea) in the Urals

This paper discusses the evolution of the Early Permian ammonoid family Paragastrioceratidae in the Urals, with an emphasis on the terminal Artinskian-Kungurian stage of evolution in this group. New data on the Kungurian members of the family are discussed. Patterns of morphological and ecological changes of the Uralian paragastrioceratids are analyzed.