| Ermoceras Temporal range: MJurassic |
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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 [1]
Telermoceras, with low, depressed whorls, and Kosmermoceras with high,compressed whorls are considered subgenera of Ermoceras [1] 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)[2] tentatively placed Ermoceras in the Thamboceratidae, based on sutural morphology, removing it from the Stephanoceratidae where it was previously included.