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Ecdysis in Flexicalymene meeki (Trilobita)

Published online by Cambridge University Press:  20 May 2016

Danita S. Brandt*
Affiliation:
Department of Geological Sciences, Michigan State University, East Lansing 48824

Abstract

The ecdysial style of Flexicalymene meeki (Foerste) from the Upper Ordovician of the Cincinnati arch (Ohio) is best characterized by a spectrum of configurations. Recurring patterns of displaced tergites and points of disarticulation indicate differential susceptibility of the exoskeleton to disarticulation during ecdysis. Specimens identified as exuviae are characterized by one or more of the following: thoracic segments displaced (unevenly spaced, disarticulated or telescoped); pygidia and/or cephala rotated away from the sagittal line; cephalon sharply bent ventrally at first thoracic segment; librigenae separated or folded ventrally along facial sutures; “extra” tergites (exuvia) superposed on the new exoskeleton; and missing elements, especially librigenae and hypostomae. The range of exuvial configurations suggests a variety of ecdysial behavior in this trilobite.

Type
Research Article
Copyright
Copyright © The Paleontological Society 

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