Echioceras

Echioceras is an extinct genus of ammonite from the Early Jurassic of Europe and North America.

Selected species

 * Echioceras raricostatum
 * Echioceras fastigiatum

Description
Shell of Echioceras species can reach a diameter of about 4–6 centimetres (1.6–2.4 in).. The narrow and broad evolute shell is reinforced by fine ribs on inner whorls, progressively becoming stronger, straight and distinct.