''Tainoceras'' is an extinct coiled cephalopod that live during the later part of the

Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ' ...

and

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

, that belongs to the nautiloid family Tainoceratidae.Kummel 1964, Nautiloidea—Nautilida. Treatise on Invertebrate Paleontology Part K Mollusca 3. Geol Soc of America and Univ Kansas Press Teichert and Moore (eds) ''Tainoceras'' has an evolude shell with a subquadrate whorl section that bears a double row of nodes on either side of its broad outer rim (venter). '' Metacoceras'' is similar except for lacking the double rows of nodes. '' Tainionautilus'' is similar, except that instead of nodes it has thick slanting lateral ribs

References

Nautiloids Pennsylvanian first appearances Triassic extinctions Fossil taxa described in 1883 Prehistoric nautiloid genera {{Paleo-nautiloid-stub