Abstract
Introduction: Because ammonoid jaws are rare (Tanabe et al. 2015) and preserved soft parts as well as radulae (Klug and Lehmann 2015; Kruta et al. 2015) are even rarer, most paleontologists are limited in the available morphological information to the conch when describing ammonoids. Taking the great diversity and disparity as well as the over 300 Ma of the clade’s existence into account, it becomes obvious that the different ammonoid clades have divergent sets of characters requiring descriptive procedures adapted to the requirements.