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] 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.
Westermann (1965)[4] tentatively placed Ermoceras in the Thamboceratidae, based on sutural morphology, removing it from the Stephanoceratidae where it was previously included.
This Ammonitina-related article is a stub.