What is "promicroceras"

Promicroceras is an extinct ammonite genus from the upper Sinemurian ( Lower Jurassic) of Europe, named by Leonard Spath in 1925. Promicroceras is included in the family Eoderoceratidae, which is part of the ammonitid superfamily Eoderocerataceae.

Shells are evolute with an open umbilicus; strongly ribbed, ribs flattened on the venter, and with small spines without distinct tubercles.