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.
Cladistic analyses have revealed that nycteroleterids are more closely related to Pareiasauria than previously thought, making Nyctiphruretus the only surviving genus in its order. In 2014, MacDougall & Reisz identified a second genus of Nyctiphruretidae, Abyssomedon, from the middle Leonardian stage of the late Early Permian in Comanche County, Oklahoma.