|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Rhynchonellata - Athyridida - Retziellidae
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. R. M. Cocks 1979||Delthyrid like Howellella but with pinched-in pedicle muscle field, and with a median rib in the sulcus of the pedicle valve and a corresponding hollow in the brachial valve fold.|