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

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...

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Bibliographic Details
Main Authors: Fuchs, Dirk, Keupp, Helmut, Klug, Christian
Format: Article in Journal/Newspaper
Language:English
Published: Taylor & Francis 2020
Subjects:
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
Description
Summary: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.