Ambonychia acuticostata (FOSSIL) F. McCoy, 1851 †
Mytilarca acutirostra (FOSSIL) (J.W. Hall, 1865 †)
Ambonychia acutirostris (FOSSIL) Ulrich, 1895 †
Elasmodophora acutirostris (FOSSIL) Isberg, 1934 †
Ambonychiopsis affinis (FOSSIL) (Ulrich, 1894 †)
Ambonychia alata (FOSSIL) F.B. Meek, 1872 †
Opisthoptera alternata (FOSSIL) Ulrich, 1895 †
Mytilarca amii (FOSSIL) McLearn, 1924 †
Ambonychinia amygdalina (FOSSIL) (J.W. Hall, 1847 †)
Cleionychia angusta (FOSSIL) (Foerste, 1918 †)
Mytilarca aphaea (FOSSIL) (J.W. Hall, 1865 †)
Mytilarca arenacea (FOSSIL) J.W. Hall& R.P. Whitfield, 1869 †
Ambonychia arundinea (FOSSIL) Tunnicliff, 1982 †
Cleionychia attenuata (FOSSIL) (J.W. Hall, 1847 †)
Claudeonychia babini (FOSSIL) Pojeta Jr., 1997 †
Ambonychiopsis bellistriata (FOSSIL) (J.W. Hall, 1847 †)
Ambonychia borealis (FOSSIL) Foerste 1924 †
Mytilarca boucoti (FOSSIL) Kriz & al., 2011 †
Claudeonychia byrnesi (FOSSIL) (Ulrich, 1895 †)
Mytilarca canadensis (FOSSIL) Billings, 1874 †
Ambonychia carinata (FOSSIL) (G.A. Goldfuss, 1836 †)
Opisthoptera casei (FOSSIL) (F.B. Meek& A.H. Worthen, 1866 †)
Mytilarca chemungensis (FOSSIL) (T.A. Conrad, 1842 †)
Mytilarca cingulosa (FOSSIL) Pohl, 1929 †
Maryonychia concordensis (FOSSIL) (Foerste, 1910 †)
Lophonychia cordata (FOSSIL) C.C. Stewart, 1933 †
Mytilarca cordiformis (FOSSIL) (J.W. Hall, 1859 †)
Ambonychinia corrugata (FOSSIL) Isberg, 1934 †
Cleionychia corrugata (FOSSIL) (Lindström, 1880 †)
Amphicoelia costata (FOSSIL) J.W. Hall& R.P. Whitfield, 1875 †
Mytilarca crassa (FOSSIL) Isberg, 1934 †
Cleionychia crebra (FOSSIL) Khalfin, 1958 †
Cleionychia crispa (FOSSIL) Khalfin, 1958 †
Mytilarca cultellata (FOSSIL) Pohl, 1929 †
Ambonychia cultrata (FOSSIL) Ulrich, 1893 †