Ermoceras

Ermoceras
Temporal range: Bajocian[1]
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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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