|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Cephalopoda - Oncocerida - Graciloceratidae
If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
|B. Kröger 2007||Porkunioceras differs from other Graciloceratidae in having nearly straight breviconic conch with angle of expansion of approximately 10 –30 that is ornamented with transverse raised lirae. Seven transverse lirae occur at one millimetre. Genus in consideration differs from Pomerantsoceras in having stumpy, ornamented shell. Cross section is compressed with ratio conch width/height 0.7. Septal spacing is narrow with approximately 0.2–0.25 of shell diameter. Septal curvature is very shallow. Sutures have shallow lateral lobe. Septal necks are achoanitic. Siphuncle is marginal, positioned at convex side of conch curvature and very thin, tubular with cross section 0.10 of conch. Apex is acute. Second septum of apex occurs at cross section diameter of approximately two millimetres. No endosiphuncular deposits known. Adult length of the conch amounts to approximately 15 mm.|