Anoploceras is a Middle and Upper Triassic nautiloid included in the Tainoceratidae

Tainoceratidae

The Tainoceratidae is a family of late Paleozoic and Triassic nautiloids that are a part of the order Nautilida, characterized by large, generally evolute shells with quadrate to rectangular whorl sections...

, known from eastern Europe. The shell is evolute with only a slight overlap of previous whorls. Whorl section is subquadrate, like Pleuronautilus

Pleuronautilus

Pleuronautilus is a Nautiloid genus; family Tainoceratidae, order Nautilida. The shell is evolute, discoidal; whorl section subquadrade, flanks generally straight but may converge toward the venter. Inner flanks have course ribbing, outer have rows of nodes. Sutures have shallow ventral,...

, only depressed. Flanks have conspicuous ribs that may be somewhat sinuous.

Holconautilus

Holconautilus

Holconautilus is a Nautiloid genus from the family Tainoceratidae and order Nautilida, named by Mojsisovics, 1902, and known from Upper Triassic sediments in Europe and E Indies...

has a more rounded venter, and flanks, and is more evolute. Enoploceras

Enoploceras

Enoploceras is a Tainoceratid genus, a nautiloid cephalopod in the order Nautilida, known from Triassic sediments in Europe, India, Timor, and the state of Idaho....

has weaker ribs that expand into nodes on the umbilical and ventro-lateral shoulders, and a small umbilical perforation. Encoiloceras

Encoiloceras

Encoiloceras is a Tainoceratid genus, a nautiloid cephalopod in the order Nautilida that has been found in Upper Triassic sediments in the Alps and Hungary....

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)