Puneet Varma (Editor)


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Kingdom  Animalia
Family  Plectronoceridae
Rank  Genus
Class  Cephalopoda
Phylum  Mollusca
Order  Plectronocerida
Plectronoceras httpsuploadwikimediaorgwikipediacommonscc

Similar  Plectronocerida, Phragmoteuthis, Styletoctopus, Pohlsepia, Ascocerida


Plectronoceras is the earliest known shelly cephalopod, dating to the Upper Cambrian. None of the fossils are complete, and none show the tip or opening of the shell. Approximately half of its shell was filled with septa; 7 were recorded in a 2 cm shell. Its shell contains transverse septa separated by about half a millimetre, with a siphuncle on its concave side. Its morphology matches closely to that hypothesised for the last common ancestor of all cephalopods.

Plectronoceras is the type genus of the family Plectronoceratidae.

PlectronocerasArtwork by Franz Anthony / @franzanthThe 501 million years old Plectronoceras had an air-filled chambered shell that helped it stay buoyant and not tied to the ocean floor, setting cephalopods apart from their close relatives, the...


Plectronoceras Wikipedia