 Axonoceras

Axonoceras is a genus in the ammonitid family Nostoceratidae proposed by Stephenson in 1941, for "slender shells coiled in a plane with numerous closely spaced ribs and two rows of ventral nodes'...The shells may be closely coiled, though not involute, but most... are more or less loosely and irregularly coiled".Shells may be coplanar or coiled in a low flat spiral with the early whorls in contact, later whorls free.