Represented mostly by Craspeditidae family, which evolved from Mid-Volgian Dorsoplanitidae and later gave birth to 2 lineages: more typical-looking Craspedites (lots of species) and disc-shaped Garniericeras. The latter evolved from smooth and round Kachpurites, with each evolutionary step becoming more and more flattened to the extent of looking almost 2D.
Late Volgian comprises 3 ammonite zones:
1. Kachpurites fulgens (good sites in Moscow region)
2. Garniericeras catenulatum/ Craspedites subditus (both names in use, sites in Moscow and various Volga regions)
3. Craspedites nodiger (less numerous sites in Moscow (Shmelovka), Kostroma and Samara)
As to preservation, they are usually fragile shells found in watery clay with iridescent nacre of various colors, often green, blue and yellow.