Gosseletina idahoensis (FOSSIL) (Girty, 1910 †)
Humboldtiella imbricata (FOSSIL) (A. Römer, 1843 †)
Peruvispira imbricata (FOSSIL) C.O. Waterhouse, 1963 †
Devonorhineoderma impendens (FOSSIL) (Sedgwick & Murchison,1840 †)
Baylea inclinata (FOSSIL) Weller, 1929 †
Deacheospira inflata (FOSSIL) (E.F.R.K. Koken, 1896 †)
Glabrocingulum inflatum (FOSSIL) Elias, 1958 †
Lahnia infranodosa (FOSSIL) (J.J.F. Whiteaves,1892 †)
Hypselentoma inornata (FOSSIL) (F.B. Meek, 1872 †)
Neilsonia insculpta (FOSSIL) (J.W. Hall, 1856 †)
Abylea insolitus (FOSSIL) Hoare & al., 1997 †
Euryzone intermedia (FOSSIL) Tolmachoff, 1930 †
Spiroscala intermedia (FOSSIL) (de Koninck, 1883 †)
Glabrocingulum interstrialis (FOSSIL) (B. Phillips, 1836 †)
Spiroscala intricata (FOSSIL) Batten, 1966 †
Neilsonia invisitata (FOSSIL) Hoare & al., 1997 †
Mourlonia italica (FOSSIL) Spitz, 1907 †
Dictyotomaria itylus (FOSSIL) (A.H. Clarke, 1904 †)
Euryzone itys (FOSSIL) (J.W. Hall, 1876 †)
Odontomaria jankei (FOSSIL) Frýda & al., 2006 †
Ananias joannisaustriae (FOSSIL) Knight 1945 †
Bradyospira johnsensis (FOSSIL) Batten, 1964 †
Gosseletina johnsoni (FOSSIL) Thein & Nitecki, 1974 †
Stenozone johnstonei (FOSSIL) (Dickins, 1961 †)
Angyomphalus junior (FOSSIL) (de Koninck, 1881 †)
Angyomphalus junius (FOSSIL) (Whidborne, 1892 †)
Frydiella kaimi (FOSSIL) Krawczynski, 2006 †
Devonorhineoderma kaulensis (FOSSIL) Heidelberger, 2003 †
Euryzone kayseri (FOSSIL) (E.F.R.K. Koken, 1889 †)
Lahnospira kayseri (FOSSIL) (Ulrich, 1892 †)
Pleurorima kayseri (FOSSIL) (A.H. Clarke & Ruedemann,1903 †)
Angyomphalus kentuckiensis (FOSSIL) Thein & Nitecki, 1974 †
Euryzone kielcensis (FOSSIL) (Gürich, 1896 †)
Baylea kirillowensis (FOSSIL) de Koninck 1881 †
Latitaenia kirnaensis (FOSSIL) E.F.R.K. Koken& J. Perner, 1925 †