Dinocephalia

Dinocephalians (terrible heads) are a clade of large-bodied early therapsids that flourished in the Early and Middle Permian between 279.5 and 260 million years ago (Ma), but became extinct during the Capitanian mass extinction event. Dinocephalians included herbivorous, carnivorous, and omnivorous forms. Many species had thickened skulls with many knobs and bony projections. Dinocephalians were the first non-mammalian therapsids to be scientifically described and their fossils are known from Russia, China, Brazil, South Africa, Zimbabwe, and Tanzania.

Phthinosuchus is an extinct genus of therapsids from the Middle Permian of Russia. Phthinosuchus is the sole member of the family Phthinosuchidae. Phthinosuchus may have been one of the most primitive therapsids, meaning that its ancestors may have branched off early from the main therapsid line.

Rhopalodon is an extinct genus of therapsids from the Permian of Russia. It has been variously classified as a dinosaur, a dinocephalian, or another branch of amniotes. Rhopalodon is notable for being among the first "reptiles" mentioned in Nature. T.H. Huxley wrote of this animal, among others, in the inaugural issue of the magazine, in November 1869. He gave the age of this animal and of the contemporary Deuterosaurus as Triassic, but both are now known to have lived during the Middle Permian.

thumb|Skull dome of Stegoceras (AMNH 5450) showing cross-section thickness

Tapinocaninus (Greek for "humble"- tapino, and "canine"- caninus) is an extinct genus of therapsids in the family Tapinocephalidae, of which it is the most basal member. Only one species is known, Tapinocaninus pamelae (meaning "Pamela's humble canine"). The species is named in honor of Rubidge's mother, Pamela. Fossils have been found dating from the Middle Permian (Wordian age).

Phthinosaurus is an extinct genus of therapsids from the Middle Permian of Russia. The type species Phthinosaurus borrisiaki was named by Soviet paleontologist Ivan Yefremov in 1940 on the basis of an isolated lower jaw. Because this jaw provides few distinguishing characteristics, the evolutionary relationships of Phthinosaurus are poorly known. Yefremov named the family Phthinosuchidae in 1954 to include Phthinosaurus and the newly named Phthinosuchus, which was described on the basis of a crushed partial skull. American paleontologist Everett C. Olson placed both of these therapsids in the

Microurania is an extinct genus of therapsids from the Middle Permian first named and described by Mikhaïl Ivakhnenko. It is known from a single partial skull found in the region of Orenburg, Russia. According to Kammerer, 2011, it likely represents the remains of a juvenile dinocephalian.

Parabradysaurus is an extinct genus of rhopalodontid dinocephalians. It is known from a few serrated teeth that indicate this animal was like herbivorous.