Wikipedia
Docidoceras
Docidoceras is an extinct ammonite genus from the order Ammonitida that lived during the Middle Jurassic. Docidoceras is included in the family Otoitidae which makes up part of the ammonite superfamily Stephanocerataceae.
Docidoceras has a broad, finely ribbed, evolute shell with a depressed whorl section. The venter,the outer rim, is broadly arched and crossed by the ribs without interruption. The dorsum, on the inner rim of the whorls is broadly impressed.