An Early Devonian nonagonal orthoconic cephalopod from Morocco

A new specimen of a Dalejan (Late Emsian, Early Devonian) orthoconic cephalopod is described from the southwestern Tafi lalt (Anti-Atlas, Morocco). It has a nonagonal cross section (with nine edges) and resembles Kionoceras. Since it differs in several characters from Kionoceras, we introduce the new taxon Amessouiceras enneagon gen. et. sp. nov. and shortly discuss evolutionary events among cephalopods in the Early Devonian.