Nyctiphruretidae
Nyctiphruretidae is an extinct family of hallucicranian parareptiles known from the late Early to the late Middle Permian of European Russia and south-central United States. Nyctiphruretidae was named by Michael S. Y. Lee (1997) together with the order Nyctiphruretia to include the type species "Nyctiphruretus acudens" known from several Middle Permian locations in European Russia. While the family was defined to be monotypic, the order was defined to include both nyctiphruretids and nycteroleterids. However, recent cladistic analyses suggest that nycteroleterids are more closely related to the Pareiasauria instead, thus making "Nyctiphruretus" the only genus of its order. In  2014, MacDougall & Reisz described and named a second genus of Nyctiphruretidae, "Abyssomedon", from the middle Leonardian stage of the late Early Permian of Comanche County, Oklahoma, south-central United States. It contains a single species, "A. williamsi", which represents the first nyctiphruretid known from North America, and the oldest species of the family. Phylogeny. Before the discovery of "Abyssomedon", all phylogenetic analyses including Säilä (2010) and Tsuji "et al." (2012) recovered Nyctiphruretidae, which was represented solely by "N. acudens", as the sister taxon of Procolophonia. However, the addition of "Abyssomedon" by MacDougall and Reisz (2014) to an updated version of  the Tsuji "et al." (2012) data-set, recovered a monophyletic Nyctiphruretidae, nested within Procolophonia as the sister taxon of Procolophonoidea - a clade formed by owenettids and procolophonids. The following cladogram is simplified after the phylogenetic analysis of MacDougall and Reisz (2014) and shows the placement of Nyctiphruretidae within Parareptilia. Relationships within bolded terminal clades are not shown.