|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||Age range and collections|
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.
|J. Pojeta et al. 1972||The new class Rostroconchia Pojeta, Runnegar, Morris, and Newell may be diagnosed as follows: mollusks having an uncoiled univalved larval shell; an untorted bivalved adult shell; no hinge teeth, ligament, or adductor muscles; and a fused, almost inflexible, hinge; Early Ordovician-Late Permian (4, 14, 19).|