Coilopoceratidae is a family of generally large, proper

ammonites Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...

with strongly involute shells from the Cretaceous,

Albian The Albian is both an age of the geologic timescale and a stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early/Lower Cretaceous Epoch/Series. Its approximate time range is 113.0 ± 1.0 Ma to 100.5 ± 0.9 M ...

Turonian The Turonian is, in the ICS' geologic timescale, the second age in the Late Cretaceous Epoch, or a stage in the Upper Cretaceous Series. It spans the time between 93.9 ± 0.8 Ma and 89.8 ± 1 Ma (million years ago). The Turonian is preceded by t ...

. Coilopoceratids have variably compressed shells with flattish to broadly rounded sides and narrowly rounded to sharp keel-like venters. Whorl sections are generally lanceolate. The suture is ammonitic with an overall clumpy appearance. The Coilopoceratidae are derived from the

Tissotiidae Tissotiidae is a family of ammonites (Ammonitina) belonging to the Acanthoceratoidea. The Tissotiidae are derived from the Vascoceratidae, another acanthoceratoid family, and gave rise to the Coilopoceratidae. They have been divided into two su ...

by a secondary re-development of an ammonitic suture and of more narrowly compressed shells.

Genera

*'' Coilopoceras'' Hyatt, 1903 (synonym = ''Glebosoceras'' Reyment, 1954) - from north and west Africa, Syria, Baluchistan, and western North America (Colorado, New Mexico, Texas). *'' Herrickiceras'' Cobban & Hook, 1980 - from Western North America, central Africa, and the Middle East. *'' Hoplitoides'' von Koenen, 1898 – from north and west Africa, Syria, Columbia, Peru, western North America.

References

*
Paleobiology Database Coilopoceratidae entry
Ammonitida families Acanthoceratoidea Turonian first appearances Coniacian extinctions {{Ammonitina-stub