Acrotretoidea
Acrotretoidea is a superfamily of brachiopods containing the following families:
| Family | Number of genera | Fossil range |
| Acrotretidae | 55 | Lower Cambrian – Silurian |
| Curticiidae | 1 | Middle – Upper Cambrian |
| Torynelasmatidae | 9 | Ordovician – Silurian |
| Eoconulidae | 3 | Ordovician |
| Ceratretidae | 8 | Lower – Upper Cambrian |
| Ephippelasmatidae | 12 | Upper Cambrian – Ordovician |
| Scaphelasmatidae | 6 | Middle Cambrian - Upper Silurian |
| Biernatidae | 5 | Lower Ordovician – Middle Devonian |