Phthinosuchus and Archaeosyodon

Phthinosuchus discors (Yefremov, 1954, 20cm skull) was considered a basal therapsid, but here was derived from Eotitanosuchus and nests basal to the derived syodontids like Syodon. It has larger palatine tooth pads like Anteosaurus.

Archaeosyodon praeventor (Tchudinov 1960; Middle Permian; est. 2m in length) nests at the base of the Syodon clade. The rostrum is short with a low naris and small premaxilla. The anterior teeth are relatively small. The canine is hooked. The maxilla is quite deep. The jugal nearly invades the orbit and the postorbital process is high.

Efremov IA 1954. The fauna of terrestrial vertebrates in the Permian copper sandstones of wester Cis-Urals: Travaux de I’institut Paleozoologique de l’Academie des Sciences de l’URSS, v. 54, 416pp.

Tchudinov 1960. Upper Permian therapsids of the Ezhovo locality: Paleontologischeskii Zhural, n. 4, p. 81-94.

wiki/Phthinosuchus
wiki/Archaeosyodon

Therapsida

Cutleria

Anomodontia

Hipposaurus

Stenocybus

Galechirus - Galepus

Patranomodon

Eodicynodon - Dicynodon

Suminia

Venjukovia • Otsheria