|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Strophomenata - Strophomenida - Glyptomenidae
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.
|L. E. Popov and L. R. M. Cocks 2014||Shell strongly concavoconvex, about fourfifths as long as wide, with the maximum width at the hinge line. Cardinal extremities acute to almost right angled. Anterior commissure rectimarginate. Ventral valve lateral profile almost evenly convex, slightly more strongly anterior to mid-length. Ventral interarea planar, apsacline with a delthyrium completely covered by the convex pseudodeltidium. Dorsal valve almost flat with a weak dorsal geniculation along the anterior and lateral margins of the mature specimens. Dorsal interarea low, planar, almost procline with a complete chilidium. Radial ornament unequally and finely parvicostellate, with up to five parvicostellae in the interspaces between accentuated ribs in the mid-valve; becoming more nearly multicostellate near the anterior margin of mature specimens, with 5–7 ribs per mm. Concentric ornament of very fine densely spaced fila. Ventral valve interior with fine teeth and thin, strongly divergent dental plates. Ventral muscle field subpentagonal and bilobed, about two-fifths as long as the valve, surrounded by strong muscle bounding ridges anteriorly and laterally. Adductor scars narrow, thickened almost half length of diductor scars, but not completely enclosed. Ventral vascula media fine, divergent. Dorsal interior with bilobed ‘Type C’ cardinal process of Rong & Cocks (1994) situated on a vestigial notothyrial platform. Long and almost straight, widely divergent, socket ridges bordering transverse sockets with five ridges on the anterior slope. Adductor scars slightly thickened, not divided by side septa. Faint median septum variably developed in valve centre. Very weak, short and curved dorsal side septa only in the valve centre. Diaphragm variably developed in both valves.|