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Plectoceras
fossil cephalopod genus
Plectoceras, extinct genus of small marine nautiloid cephalopods, forms related to the modern pearly nautilus, that had a coiled shell composed of a series of chambers; Plectoceras was active in the Ordovician Period (from about 488 million to 444 million years ago). The junctures between successive chambers of Plectoceras were simple in character.
This article was most recently revised and updated by Richard Pallardy.
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