Eotitanosuchus, Rubidgina and Inostrancevia

Eotitanosuchus olsoni (Tchudinov 1960, 35 cm juvenile skull, PIN 1758/1l) derived from a sister to Biarmosuchus, this taxon was basal to gorgonopsids, like Gorgonops and Therocephalians (including cynodonts and mammals).

The longer rostrum and canine fangs mark Eotitanosuchus as a predator. The temporal fenestra is enlarged relative to that of Biarmosuchus.

Inostrancevia alexandri (Amalitsky 1922; Late Permian, 260 mya; 3.5m in length) is considered the largest member of the Gorgonopsidade. It is known from several skulls and two post-crania. Here it nests at the base of the Theriodonta, close to Eotitanosuchus, with which it shares many traits, including large size. Another close relative, Aloposaurus, is the smallest known gorgonopsid.

Rubidgina angusticeps (Broom 1942, RC55, Late Permian) was considered a biarmosuchian, but here nests basal to gorgonopsians on one branch and therocephalians on the other. Rubidgina was derived from a sister to Inostrancevia. The orbits were rotated anteriorly to a greater extent than would be seen in sister taxa.

Amalitsky VP 1922. Diagnoses of the new forms of vertebrates and plants from the upper Permian of North Dvina. Bulletin of the Russian Academy of Sciences. Saint Petersburg. 16 (6): 329–340.

Broom R 1942. Rubidginidae: C J Kitching and party. Bulletin of the South African Museum Association 2:36.

Tchudinov PK 1960. Upper Permian therapsids from the Ezhovo locality (Verkhnepermskie terapsidy) ezhovskogo mestonakhozhdenip). Paleontologicheskii Zhurnal 1960(4):81-94.

wiki/Eotitanosuchus
wiki/Inostrancevia
wiki/Rubidgina

Therapsida

Cutleria

Anomodontia

Hipposaurus

Stenocybus

Galechirus - Galepus

Patranomodon

Eodicynodon - Dicynodon

Suminia

Venjukovia • Otsheria

Tiarajudens