Acrotretidae Schuchert, 1893 † (original description)
Acrotretoidea Schuchert, 1893 † (original description)
Billingsellida † (original description)
Billingsellidae Schuchert, 1893 † (original description)
Billingsellidina † (original description)
Eichwaldiidae Schuchert, 1893 † (original description)
Eichwaldioidea Schuchert, 1893 † (original description)
Kutorginidae Schuchert, 1893 † (original description)
Kutorginoidea Schuchert, 1893 † (original description)
Lingulellinae Schuchert, 1893 † (original description)
Paterinidae Schuchert, 1893 † (original description)
Paterinoidea Schuchert, 1893 † (original description)
Rafinesquinidae Schuchert, 1893 † (original description)
Rafinesquininae Schuchert, 1893 † (original description)
Trematidae Schuchert, 1893 † (original description)
Trigonotretidae Schuchert, 1893 † (original description)
Trigonotretinae Schuchert, 1893 † (original description)