New Early Permian Nautilids of the Family Rhiphaeoceratidae of the Shakhtau Reef (Bashkortostan).

The article reviews the evolution of the family Rhiphaeoceratidae and provides information on the stratigraphic and geographical distribution of its representatives. A new genus Eximioceras with the type species E. venustum sp. nov. and a new species Pararhiphaeoceras parvum, also belonging to this family, are described within Rhiphaeoceratidae. New records expand our understanding of the taxonomic diversity of the Shakhtau Reef cephalopod community and add to its ecological interpretation. [ABSTRACT FROM AUTHOR]