Kingdom Animalia Linnaeus, 1758 - animals
   Phylum Mollusca Linnaeus, 1758 - molluscs
     Subphylum Diasoma Runnegar & Pojeta Jr., 1974 see Phylum Mollusca Linnaeus, 1758
       Class †Rostroconchia Pojeta et al., 1972
         Order †Ribeirioida Kobayashi, 1933
           Genus †Apoptopegma Pojeta, Gilbert-Tomlinson & Shergold, 1977
           Genus †Cymatopegma Pojeta, Gilbert-Tomlinson & Shergold, 1977
           Genus †Heraultipegma Pojeta & Runnegar, 1976
           Genus †Ischyrinia Billings, 1866
           Genus †Kimopegma Pojeta, Gilbert-Tomlinson & Shergold, 1977
           Genus †Myocaris Salter, 1864
           Genus †Oepikila Runnegar & Pojeta, 1974
           Genus †Pauropegma Pojeta, Gilbert-Tomlinson & Shergold, 1977
           Genus †Pinnocaris Etheridge, 1878
           Genus †Ptychopegma Pojeta, Gilbert-Tomlinson & Shergold, 1977
           Genus †Ribeiria Sharpe, 1853
           Genus †Technophorus Miller, 1889
           Genus †Tolmachovia Howell & Kobayashi, 1936