Revision of the Early Permian ammonoid family Perrinitidae

The perrinitids are biostratigraphically significant, provincial Lower Permian ammonitic Goniatitina characterized by subglobose to thickly subdiscoidal, narrowly umbilicate conchs. The suture fundamentally displays a three-fold division of the external lateral, umbilical and internal lateral lobes. With the aid of a considerable body of new data concerning the internal suture and sutural ontogenies, it is now expedient to arrange the perrinitids in two subfamilies, the Perrinitinae and Paraperrinitinae. The Perrinitinae have relatively simple internal sutures and comprise the ancestral Subperrinites n. gen. and the descendant Perrinites Boese. The Paraperrinitinae have relatively complex internal sutures and comprise the ancestral Properrinites Elias and the descendant Paraperrinites Toumanskaya.--Modified journal abstract.