''Mecynoceras'' is a genus of Late Devonian
oncocerids included in the
Poterioceratidae, 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 biological tissue, tissue passing longitudinally through the mollusc shell, shell of a cephalopod mollusc. Only cephalopods with chambered shells have siphuncles, such as the extinct ammonites and belemnites, and the li ...
large, subcentral, with actinosiphonate deposits.
''
Cyrtogomphus'', ''
Lysagoroceras'', and ''
Poterioceras'' are among related genera.
References
* Walter C. Sweet, 1964. Nautiloidea-Oncocerida.
Treatise on Invertebrate Paleontology
The ''Treatise on Invertebrate Paleontology,'' published from 1953–2007 by the Geological Society of America and the University of Kansas, then 2009–present by the University of Kansas Paleontological Institute, is a definitive multi-authore ...
, Part K. Geological Society of America.
''Mecynoceras''Fossilworks entry.
Prehistoric nautiloid genera
Oncocerida
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