Feeserpeton oklahomensis (Macdougall and Reisz 2012; Early Permian) Originally it was considered a “parareptile” that nested with Acleistorhinus and Lanthanosuchus. Here Feeserpeton nested as a sister to Australothyris. Milleretta RC14 and Saurorictus are very close to the base of these two.Acleistorhinus and the Caseasauria (Oedaleops) were sister clades.

Smaller overall and distinct from Milleretta RC 14, Feeserpeton had a shorter skull and large lateral temporal fenestra. The basiocciput was shorter and wider. The basipterygoid processes were smaller. Two maxillary teeth were robust.

Eocasea martini (Reisz and Fröbisch 2014, Late Pennsylvanian) is not the basalmost caseid, but is close to the related clade that produced Eunotosaurus and Acleistorhinus. It had a long narrow torso and short legs.

Macdougall MJ and Reisz R 2012. A new parareptile (Parareptilia, Lanthanosuchoidea) from the Early Permian of Oklahoma, Journal of Vertebrate Paleontology, 32:5, 1018-1026.

Reisz R and Fröbisch J 2014. The oldest caseid synapsid from the Late Pennsylvanian of Kansas, and the Evolution of Herbivory in Terrestrial Vertebrates. PLoS ONE 9(4): e94518. doi:10.1371/journal.pone.0094518

wiki/Feeserpeton
wiki/Eocasea