Form and formation of flares and parabolae based on new observations of the internal shell structure in lytoceratid and perisphinctid ammonoids

The ultrastructure of pristine shells of Jurassic and Cretaceous lytoceratid and perisphinctid ammonoids indicates that flares and parabolae represent homologous structures. Both mark an interruption of shell growth. We dismiss earlier interpretations of parabolae as actual aperture, relics of resor...

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Bibliographic Details
Main Authors: Gregor Radtke, René Hoffmann, Helmut Keupp
Format: Article
Language:English
Published: Institute of Paleobiology PAS 2016-08-01
Series:Acta Palaeontologica Polonica
Subjects:
Online Access:http://www.app.pan.pl/archive/published/app61/app001542015.pdf