Taxonomic revision of ?Onychoteuthis? conocauda Quenstedt, 1849 (Cephalopoda: Coleoidea)
Fuchs, Dirk; Donovan, Desmond T.; Keupp, Helmut
published: Dec 1, 2013
ArtNo. ESP155027003002, Price: 29.00 €
For Phragmoteuthis conocauda (Quenstedt, 1849) from the Lower Toarcian Posidonia Shale (South Germany) and Phragmoteuthis montefiorei (Buckman, 1880) from the Upper Sinemurian Charmouth Mudstone Formation (Dorset, UK), a new belemnoid genus, Clarkeiteuthis, is introduced. Clarkeiteuthis significantly differs from Phragmoteuthis by the absence of a three-lobed proostracum as well as the possession of a unique hook shape. Owing to the presence of a proostracum, which is significantly narrower than in belemnotheutids, Clarkeiteuthis is accommodated within the Diplobelida. This taxonomic revision has an influence on our previous knowledge about the Phragmoteuthida. The taxon already disappeared after the Sinemurian (instead of Toarcian). Hence, the youngest known representative of the Phragmoteuthida is Phragmoteuthis huxleyi Donovan, 2006. The true number of arms, which was originally based on the ten arms of Clarkeiteuthis conocauda, is still unknown in phragmoteuthid belemnoids. The new assignment of Clarkeiteuthis conocauda and Clarkeiteuthis montefiorei induces the presence of hooklets (onychites) within the Diplobelida, which was previously questioned.