Tainoceras luxaeterna sp. nov., a new Late Pennsylvanian nautiloid species (Cephalopoda) from the Donets Basin, eastern Ukraine

The coiled nautiloid Tainoceras luxaeterna sp. nov. is described from the late Kasimovian or early Gzhelian (Late Pennsylvanian) Avilovka Formation in the Donets Basin (Ukraine). It is the first Late Pennsylvanian cephalopod record in Ukraine. The new species is one of the stratigraphically oldest representatives of the genus.