Original paper

Rare representatives in the ammonoid fauna from Büdesheim (Cephalopoda, Eifel, Late Devonian) and the role of heterochrony

Korn, Dieter; Bockwinkel, Jürgen; Ebbighausen, Volker; Walton, Sonny A.


Members of the genera Archoceras and Beloceras are very rare representatives in the ammonoid assemblage from the Frasnian (Late Devonian) Büdesheim Shales. These two genera occupy a position at the margins of the morphological spectrum within the fauna; Archoceras is interpreted as a paedomorphic form characterised by a reduction in morphological complexity in conch shape and suture line, while Beloceras is characterised by an increasing complexity in conch shape and suture line.