Cabarzia trostheidei (Spindler, Werneberg and Schneider 2019; Early Permian; NML-G2017/001) is a skull-less taxon that nests with Apsisaurus, a basalmost synapsid. Originally Cabarzia was considered close to Mesenosaurus.

Distinct from related taxa, Cabarzia had anteriorly elongate ilia, four sacrals, perforated pelvis, offset femoral heads and attenuated tail, all indicating a facultative bipedal configuration.

Apsisaurus witteri (Laurin 1991) Early Permian, skull length ~5 cm, was originally considered a basal eosuchian. Reisz, Laurin and Marjanovic (2010) regarded it as a varanopid synapsid. Here Apsisaurus nests at the base of the eupelycosaurian synapsids, just outside of the protodiapsida and basal varanopidae. Thus it was in the lineage of mammals and humans.

Elliotsmithia longiceps (Broom 1937, Late Permian) nests at the base of the synapsida and, despite its late appearance, this is the most primitive taxon with a lateral temporal fenestra in the synapsid line. Derived from Echinerpeton and Protorothyris, Elliotsmithia nests with Aerosaurus.

Broom R 1937. A further contribution to our knowledge of the fossil reptiles of the Karroo. Proceedings of the Zoological Society, Series B 1937:299-318.

Reisz R 1972. Pelycosaurian reptiles from the Middle Pennsylvanian of North America. Bulletin of the Museum of Comparative Zoology 144 (2): 27–62.

Reisz RR, Dilkes DW and Berman DS 1998. Anatomy and relationships of Elliotsmithia longiceps Broom, a small synapsid (Eupelycosauria: Varanopseidae) from the late Permian of South Africa. Journal of Vertebrate Paleontology 18(3):602-611.

Reisz RR, Laurin M and Marjanovic D 2010. Apsisaurus witteri from the Lower Permian of Texas: yet another small varanopid synapsid, not a diapsid. Journal of Vertebrate Paleontology. 30 (5): 1628–1631.

Romer AS 1937. New genera and species of pelycosaurian reptiles. Proceedings of the New England Zoological Club 16:90-96.

Spindler F, Werneberg R and Schneider JW 2019. A new mesenosaurine from the lower Permian of Germany and the postcrania of Mesenosaurus: implications for early amniote comparative osteology. PalZ Paläontologische Gesellschaf

Williston SW 1914.The osteology of some American Permian vertebrates, 1. Contributions of the Walker Museum 1:107-162.

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