Anoploceras is a genus of Middle and Upper Triassic nautiloids included in the Tainoceratidae, known from eastern Europe. The shell is evolute with only a slight overlap of previous whorls. Whorl section is subquadrate, like Pleuronautilus, only depressed. Flanks have conspicuous ribs that may be somewhat sinuous. Holconautilus has a more rounded venter, and flanks, and is more evolute. Enoploceras has weaker ribs that expand into nodes on the umbilical and ventro-lateral shoulders, and a small umbilical perforation. Encoiloceras has strong ribbing, a large umbilical perforation, and a shallow groove along the venter. References Bernhard Kummel, 1964. Nautiloidea-Nautilida. Treatise on Invertebrate Paleontology, Part K. Geological Soc. of America and University of Kansas press. Teichert and Moore (eds) Prehistoric nautiloid genera Middle Triassic first appearances Late Triassic extinctions