New representatives of the family Melagathiceratidae (Ammonoidea) from the Lower Triassic of South Primorye
A new ammonoid genus, Ussurijuvenites (Melagathiceratidae), is described from the early Olenekian of South Primorye, represented by two new species (U. popovi sp. nov. and U. artyomensis sp. nov.); data on the inner shell structure of melagathiceratid ammonoids (based on U. artyomensis sp. nov.) are presented for the first time.