Family † Ptycholepididae Brough 1939, spelling in prevailing recent practice

† Ptycholepidae Brough 1939: 57 (family) † Ptycholepis Agassiz 1832 [family name also seen as † Ptycholepididae]

†Boreosomidae Gardiner 1967: 177 (family) † Boreosomus Stensiö 1921