''Mecynoceras'' is a genus of Late Devonian
oncocerids included in the
Poterioceratidae
Poterioceratidae is a family of nautiloid cephalopods included in the Oncocerida that lived during the period from the Early Devonian to the Early Carboniferous ( Mississippian). Members of the Poterioceratidae are distinguished by a subcircular ...
, a family of subcircular to compressed exogastric cyrtocones without a hyponomic sinus.
''Mecynoceras'' has a compressed, gibbous cyrtoconic shell. The venter, especially of the chambered phragmocone is convex in profile; the body chamber long and tubular. Septa are transverse, close spaced; the
siphuncle
The siphuncle is a strand of tissue passing longitudinally through the shell of a cephalopod mollusk. Only cephalopods with chambered shells have siphuncles, such as the extinct ammonites and belemnites, and the living nautiluses, cuttlefish, and ...
large, subcentral, with actinosiphonate deposits.
''
Cyrtogomphus'', ''
Lysagoroceras'', and ''
Poterioceras'' are among related genera.
References
* Walter C. Sweet, 1964. Nautiloidea-Oncocerida. Treatise on Invertebrate Paleontology, Part K. Geological Society of America.
''Mecynoceras''Fossilworks entry.
Prehistoric nautiloid genera
Oncocerida
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