Rubidgeinae

Rubidgeinae Temporal range: Late Permian, ~ As. S Artin. Kung. Road. W Ca. Wu. C
Visualized head of Rubidgea atrox
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Synapsida
Clade:	Therapsida
Clade:	†Gorgonopsia
Family:	†Gorgonopsidae
Subfamily:	†Rubidgeinae Broom, 1938
Genera
†Aelurognathus †Sycosaurus †Ruhuhucerberus †Rubidgeini †Clelandina †Dinogorgon †Leontosaurus †Rubidgea

Rubidgeinae is an extinct subfamily of gorgonopsid therapsids known only from Africa. They were among the largest gorgonopsians, and their fossils are common in the Cistecephalus and Daptocephalus assemblage zones of the Karoo Basin. They lived during the Late Permian, and became extinct at the near the end of the Permian.

Classification and systematics

Initially, the clade consisted of thirty six nominal species, however the number has been reduced over the recent years, with Kammerer (2016) recovering nine valid species within the clade.

Cladogram recovered by Kammerer (2016).

Rubidgeinae	Smilesaurus ferox Aelurognathus tigriceps Ruhuhucerberus haughtoni Sycosaurus laticeps Sycosaurus nowaki Rubidgeini Leontosaurus vanderhosti Dinogorgon rubidgei Rubidgea atrox Clelandina rubidgei

Description

Rubidgeines were large, quadrupedal carnivores of the family Gorgonopsidae, which was part larger clade Their largest teeth are their upper canines, which were blade-like and had well-developed serrations. Their postcanine teeth were small and conical, but were also frequently serrated. Tooth replacement was rapid relative to basal therocephalians. Rubidgeines can be distinguished from other gorgonopsians by the absence of a blade-like parasphenoid bone and reduced or absent preparietal bone. The jugal bone, while narrow in most gorgonopsians, was often broadly expanded in rubidgeines. The largest rubidgeines were Dinogorgon and Rubidgea.

Paleobiology

Clelandina rubidgei

Rubidgeines were among the largest gorgonopsians known, and the largest known from Africa. They were also the largest predators in their environment. Their massive canines and serrated teeth indicate that they were adapted for macropredation. The robust skull roof and supraorbital bosses of rubidgeines likely acted to protect the skull from the stress inflicted during prey capture, and similar morphology has been seen in many other macropredators in the fossil record, including theropod dinosaurs. The presence of this skull morphology is one of multiple adaptations seen in predators that utilize the skull, rather than the limbs, in prey capture.