Pareiasauromorpha was first used to define a group of parareptilians in 2011 by Linda A. Tsuji.[1] The next year, Tsuji and her colleagues used Pareiasauromorpha as a node inside Procolophonia. In their 2012 publication, Tsuji et al. defined it as a monophyletic node containing "nycteroleters" (the family Nycteroleteridae) and "pareiasaurs" (in the superfamily Pareiasauroidea).[2]
Nycteroleteridae is a family, commonly called "nycteroleters", classified in Pareiasauromorpha. The group includes the genera Emeroleter, Nycteroleter, Bashykroleter, Rhipaeosaurus, Macroleter, and "Bashykroleter" mesensis. The genus Tokosaurus is often classified as the sister taxon to Macroleter, but is actually more likely a juvenile of the later. Bashykroleter, including both species, is now considered paraphyletic, as "B." mesensis is more closely related to other genera than the type species B. bashkyricus.[1][2]
Pareiasauroidea is a superfamily, called "pareiasaurs", that is classified as the sister group to "nycteroleters". It includes many genera, and in some classifications, is grouped with Macroleter as the most basal member, or the sister taxon, with Macroleter outside of Nycteroleteridae.[1] Apart from the possible genus Macroleter, the species "Bradysaurus" seeleyi is often classified outside its genus as the most primitive species,[1] with the genus also classified as basal.[1][2]
Phylogeny
The cladogram below was found in 2011 by Tsuji,[1] and modified in 2012 by Tsuji et al.:[2]
A later study of parareptilian relationships published by Cisneros et al. (2021) recovered a diphyletic Lanthanosuchoidea, with Lanthanosuchus nested within Pareiasauromorpha:[3]
