Ephippioceratidae is a family of clydonatilacean nautilids with shells as in the

Liroceratidae Liroceratidae is an extinct family of nautilids, shelled marine molluscs, belonging to the Clydonautiloidea, consisting of generally smooth, involute, nautiliconic forms with a small umbilicus. The whorl section is usually depressed and broadl ...

but with sutures that have deep ventral and dorsal saddles. This group, which contains two genera, ''Ephippioceras'' and ''Megaglossoceras'', has a range from the Mississippian to the Lower Permian. ''Ephippioceras'', which has the full range of the family, has a broad, narrowly peaked ( V-shaped) ventral saddle and may have been derived from '' Liroceras'' early in the

Mississippian Mississippian may refer to: * Mississippian (geology), a subperiod of the Carboniferous period in the geologic timescale, roughly 360 to 325 million years ago * Mississippian cultures, a network of precontact cultures across the midwest and Easte ...

. ''Megaglossoceras'' from the

Pennsylvanian Pennsylvanian may refer to: * A person or thing from Pennsylvania * Pennsylvanian (geology) The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, on the International Commission on Stratigraphy, ICS geologic timesc ...

of North America, with its large, broadly arched, tongue-like ventral saddle is an obvious offshoot of ''Ephippioceras''. Both are subglobular and involute with a reniform whorl section. ''Ephippioceras'' has been found in North America, Europe, and China.

References

*Bernhard Kummel, 1964. Nautiloidea -Nautilida;

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and the University of Kansas, then 2009–present by the University of Kansas Paleontological Institute, is a definitive multi-authore ...

, Part K. Geol Soc of America and Univ of Kansas press, R.C. Moore (ed) {{Taxonbar, from=Q5382221 Nautiloids Mississippian first appearances Cisuralian extinctions