Superfamily

There is no reason to deny a natural sequence or to split off genera only to have to attempt later to re-insert them into the whole by means of subordos and superfamilies.

The genus Saipanetta has been suggested to be a surviving relict of the metacopidan superfamily Healdiacea because of its muscle scar pattern and narrow duplicature; nevertheless, it differs from the Metacopida in its more complex hingement, lack of a distinct contact groove, exaggerated domiciliar asymmetry, and lack of posterior ridges or angulations.