|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Strophomenata - Strophomenida - Sowerbyellidae
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.
|E. Egerquist 1999||Shell concavo-convex, with maximum width along the cardinal margin, cardinal angles drawn out into pointed alae. Radial ornamentation equally parvicostellate with two diverging accentuated costae. A convex pseudodeltidium covers the main part of the delthyrial aperture. Ventral interior with median ridge anterior to the muscle field and a medianly divided peripheral rim. Dorsal interior with a low lophophore platform surrounded by a rim; bema anteriorly elevated on two submedian septa. Socket plates fused with simple, undercut cardinal process.|