†Procolophonia Seeley 1888 [Laurin & Reisz 1995] †Procolophonoidea Romer 1956 [Lee 1995] see Superfamily Procolophonoidea Cope, 1889 †Procolophonidae Lydekker 1889 [Laurin & Reisz 1995] see Family Procolophonidae Lydekker, 1889 †Leptopleuroninae Ivakhnenko 1979 [Modesto et al. 2002] see Subfamily Leptopleuroninae Ivakhnenko, 1979 Genus †Hypsognathus Gilmore, 1928 †Hypsognathus fenneri Gilmore, 1928