A critical review of Antarcticeras Doguzhaeva, 2017 – teuthid affinities can explain the poorly mineralized phragmocone

• Main Authors: Fuchs, Dirk, Keupp, Helmut, Klug, Christian
• Format: Article in Journal/Newspaper
• Language: English
• Published: Taylor & Francis 2020
• Subjects: Department of Paleontology; 560 Fossils & prehistoric life; Antarc*; Antarctica; Seymour Island
• Online Access: https://www.zora.uzh.ch/id/eprint/151315/; https://www.zora.uzh.ch/id/eprint/151315/1/2018_FuchsKeuppKlug_ReviewAntarcticeras.pdf; https://doi.org/10.5167/uzh-151315; https://doi.org/10.1080/08912963.2018.1467905

Antarcticeras from the Early Eocene of Seymour Island (Antarctica) has recently been described as a representative of the ‘Paracoleoidea’, a previously unknown cephalopod subclass. After reinvestigation of the type material of Antarcticeras nordenskjoeldi Doguzhaeva, 2017, the justification of this new cephalopod subclass is here rejected. Phragmocone characteristics allow alternative interpretations and these justify to consider the poorly mineralized phragmocone of Antarcticeras being transitional between a heavily mineralized, fully functional phragmocone and a completely demineralized gladius of an oegopsid coleoid. Eocene Antarcticeras therefore might represent the first evidence of teuthid shell remains in the fossil record. Its poor state of mineralization accordingly suggests remarkably late development of teuthid gladii.