''Ustia'' is an extinct

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

biarmosuchia Biarmosuchia is an extinct clade of non-mammalian synapsids from the Permian. Biarmosuchians are the most basal group of the therapsids. They were moderately-sized, lightly built carnivores, intermediate in form between basal sphenacodont " pel ...

n therapsids from the

Middle Permian The Guadalupian is the second and middle series/epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico and Texas, and dates between 272.95 ± 0. ...

of Russia. It is known from a single species, ''Ustia atra'', which was described in 2003 from an isolated lower jaw. ''Ustia'' was classified in the family Ictidorhinidae, which also includes the genus '' Ictidorhinus'' from South Africa. Both are relatively small biarmosuchians. Several other Russian therapsids known only from lower jaw bones have been placed in Ictidorhinidae, and the family is likely a

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

assemblage representing a small body type than a true

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

References

Biarmosuchia Prehistoric therapsid genera Guadalupian synapsids of Europe Fossil taxa described in 2003 {{paleo-therapsid-stub