|Basic info||Taxonomic history||Classification||Relationships|
|Morphology||Ecology and taphonomy||Age range and collections|
Bivalvia - Pholadida - Vacunellidae
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. B. Waterhouse 1965||Inflated shells with anterior orthogyrous umbones, and a shallow depression near the anterior margin in some forms and below the umbo in others. Posterior umbonal ridge well rOWlded in cross-profile, posterior dorsal face concave. Moderately wide posterior dorsal gape. Ornament of concentric wrinkles, costae and very fine pustules. Shell thin, of Simple platy structure. Ligament opisthodetic, parinvicular, supported by sturdy nymphs, contained in moderately defined depression. Anterior adductor (Fig. 21) placed close to anterior ventral extremity, attached by attenuated portion of isthmus to deeply impressed protractor. Anterior retractor lies closer to the umbo on the anterior umbonal ridge. Posterior adductor large (Fig. 3H), placed close to the hinge, posterior retractor elongate, attached to adductor, sub rectangular posteriorly, extended well beyond adductor anteriorly. Pallial line probably with a large shallow sinus. Hinge edentulous, thickened under nymphS and in front of umbo.|