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 [3]

Ermoceras
Temporal range: Bajocian[1]
Scientific classification
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Ermoceras
Species [2]

Telermoceras, with low, depressed whorls, and Kosmermoceras with high, compressed whorls are considered subgenera of Ermoceras [3] 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)[4] tentatively placed Ermoceras in the Thamboceratidae, based on sutural morphology, removing it from the Stephanoceratidae where it was previously included.

References edit

  1. ^ Sepkoski, Jack (2002). "Sepkoski's Online Genus Database". Retrieved 2014-05-28. {{cite journal}}: Cite journal requires |journal= (help)
  2. ^ "Paleobiology Database - Ermoceras". Retrieved 2017-10-19.
  3. ^ a b Arkell et al 1957, Mesozoic Ammonoidea, Treatise on Invertebrate Paleontology, Part L, Ammonoidea
  4. ^ 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