Ermoceras

Ermoceras
Temporal range: Bajocian[1]
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Subclass: Ammonoidea
Order: Ammonitida
Suborder: Ammonitina
Superfamily: Stephanocerataceae
Family: Thomboceratidae
Genus: Ermoceras

Ermoceras is a thomboceratid ammonite from the Middle Jurassic ( u Baj) 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 [2]

Telermoceras, with low, depressed whorls, and Kosmermoceras with high,compressed whorls are considered subgenera of Ermoceras [2] Both are from the same time and region. Telermoceras has coarse secondary ribs and a deep umbilicus surrounded by large tubercles or spines. Kosmermocerashas fine sharp to coarse ribbing and a flattish venter

Ermoceras s.l. is derived from Arkelloceras. Westermann (1965)[3] tentatively placed Ermoceras in the Thamboceratidae, based on sutural morphology, removing it from the Stephanoceratidae where it was previously included.

References

  1. Sepkoski, Jack (2002). "Sepkoski's Online Genus Database". Retrieved 2014-05-28.
  2. 1 2 Arkell et al 1957, Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L, Ammonoidea
  3. 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
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