Ennatosaurus tecton (Maddin, Sidor and Reisz 2008) was a much smaller, late surviving caseid from the late Middle Permian, but it was a primitive caseid derived from the clade of Eothyris and Oedaleops and basal to Casea and Cotylorhynchus.

Much larger and distinct from Oedaleops the skull of Ennatosaurus was taller with a shorter rostrum, a larger naris and larger lateral temporal fenestra. The premaxilla included only two teeth. The nasal did not extend laterally but had parallel sides. The jugal had a substantial anterior (suborbital) process. The teeth were blunt.

The torso was larger with a more robust but shorter tail. The front limbs were sprawling, but the hind limbs were erect.

Datheosaurus macrourus (Schroeder 1904, Spindler, Falconnet and Fröbisch 2016, Artinskian, Early Permian, 285 mya) was a basal caseasaur, basal to Ennatosaurus and Casea and a sister to Eothyris, all derived from a sister to Eocasea and before that, Milleretta RC70. It was originally and later (Romer and Price 1940) considered a sister to Haptodus. At present the part and counterpart fossils have not been fully worked out.

Callibrachion gaudryi (Boule and Glangeaud, 1893b; Spindler, Falconnet and Fröbisch 2016) was similar and larger, butis less completely known.

Boule M and Glangeaud P 1893a. Le Callibrachion Gaudryi, nouveau reptile fossile du Permien d'Autun. Bulletin de la Société d'Histoire naturelle d'Autun 6: 199–215.

Maddin HC, Sidor CA and Reisz RR 2008. Cranial anatomy of Ennatosaurus tecton (Synapsida: Caseidae) from the Middle Permian of Russia and the Evolutionary relationships of Caseidae. Journal of Vertebrate Paleontology 28(1):160-180. online pdf

Romer AS and Price LI 1940. Review of the Pelycosauria. Geological Society of America Special Papers 28: 1-538.

Schroeder H 1904. Datheosaurus macrourus nov. gen. nov. sp. aus dem Rotliegenden von Neurode. Jahrbuch der Königlich Preußischen Geologischen Landesanstalt und Bergakademie 25 (2): 282–294. [reprint 1905]

Spindler F, Falconnet j and Fröbisch J 2016. Callibrachion and Datheosaurus, two historical and previously mistaken basal caseasaurian synapsids from Europe. Acta Palaeontologica Polonica 61: xx-xx. http://dx.doi.org/10.4202/app.00221.2015
online pdf