Biarmosuchia

'', a biarmosuchian with strange bumps and bosses on its skull, from the Late Permian of Russia The biarmosuchian skull is very similar to the sphenacodontid skull, differing only in the larger temporal fenestra (although these are still small relative to later therapsids), slightly backward-sloping occiput (the reverse of the pelycosaur condition), reduced number of teeth, and single large canine teeth in both upper and lower jaws, and other features (Carroll 1988 pp. 370, Benton 2000 p. 114). In later specialised Biarmosuchia, these resemble the enlarged canines of the Gorgonopsia. The presence of larger jaw-closing muscles (and hence a stronger bite) is indicated by the flaring of the rear of the skull where these muscles were attached. Burnetiamorphs, which made up the majority of biarmosuchian diversity, were characterized by elaborate cranial ornamentation consisting of bumps and bosses. Some burnetiids have a thick domed skull reminiscent of dinocephalians and pachycephalosaur dinosaurs. The vertebrae are also sphenacodontid-like (but lack the long neural spines that distinguish Dimetrodon and its kin), but the shoulder and pelvic girdles and the limbs indicate a much more advanced posture. The feet are more symmetrical, indicating that they faced forward throughout the stride, and the phalanges (fingers/toes) are reduced in length so that they are more like that of later synapsids (therapsids and mammals) (Carroll 1988 pp. 370–1). Biarmosuchians ranged in size from relatively small species with skulls 10–15 cm in length to large species such as Biarmosuchus, which may have had a skull in length. ==Distribution==

Currently the most representative group of the Biarmosuchia, the Burnetiamorpha, comprise ten genera: Bullacephalus, Burnetia, Lemurosaurus, Lobalopex, Lophorhinus, Paraburnetia, and Pachydectes from South Africa, Niuksenitia and Proburnetia from Russia, and Lende (MAL 290) from Malawi. In addition, Sidor et al. (2010) recently described a partial skull roof including the dorsal margin of orbits and parietal foramen of an unnamed burnetiid from the upper Permian of Tanzania, and Sidor et al. (2014) noted the presence of a burnetiid in the middle Permian of Zambia. Other Biarmosuchia include Biarmosuchus from Russia, Hipposaurus, Herpetoskylax, Ictidorhinus and Lycaenodon from South Africa, and Wantulignathus from Zambia. ==Classification==

}} }} }} }} }} }} }} }} }} }} }} }} }} }} }} Biarmosuchians are typically considered the most basal major lineage of therapsids. Denise Sigogneau-Russell (1989) erected the infraorder Biarmosuchia to include the families Biarmosuchidae, Hipposauridae and Ictidorhinidae, distinct from Eotitanosuchia and Phthinosuchia. Ivakhnenko (1999) argued that Biarmosuchus tener, Eotitanosuchus olsoni, and Ivantosaurus ensifer, all known from the Ezhovo locality, Ocher Faunal Assemblage, are actually the same species. Even if these taxa are shown to be distinct, Ivakhnenko's paper indicates that Eotitanosuchus and Biarmosuchus are very similar animals. Ivakhnenko also relocates the family Eotitanosuchidae to the order Titanosuchia, superorder Dinocephalia. Benton 2000 and 2004 gives the Biarmosuchia the rank of suborder. ==Paleoecology==

Biarmosuchians were rare components of their ecosystems; only one specimen is known for most species. though they were generally not apex predators. ==See also==