''Ermoceras'' is a genus of ammonite belonging to the Thomboceratidae family of the Middle Jurassic ( u Baj) found in deposites of central Arabia, Sinai, and Algeria with strong primary and secondary ribs and a single row of lateral tubercles; described as having a deep ventral groove Arkell et al 1957, Mesozoic Ammonoidea,

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 L, Ammonoidea ''Telermoceras'', with low, depressed whorls, and ''Kosmermoceras'' with high, compressed whorls are considered subgenera of ''Ermoceras'' Both are from the same time and region. ''Telermoceras'' has coarse secondary ribs and a deep umbilicus surrounded by large tubercles or spines. ''Kosmermoceras''has fine sharp to coarse ribbing and a flattish venter ''Ermoceras'' ''s.l.'' is derived from '' Arkelloceras''. Westermann (1965)Westernamm ,G. E. G. 1965.Septal and Sutural Patterns in Evolution and Taxonomy of Thamboceratidae and Clydoniceratidae (M Jurassic Ammonitina).Jour of Paleontology 39(5)864-874, Sept tentatively placed ''Ermoceras'' in the Thamboceratidae, based on sutural morphology, removing it from the

Stephanoceratidae Stephanoceratidae is a family of planulate and coronate ammonites within the Stephanoceratoidea Stephanoceratoidea, formerly Stephanocerataceae, is a superfamily of middle- upper Jurassic ammonoid cephalopods within the order Ammonitida cont ...

where it was previously included.

References

Jurassic ammonites Jurassic animals of Africa Bajocian life Ammonitida genera Stephanoceratoidea {{ammonitina-stub