''Scalopodon'' 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 ...

of therocephalian therapsids from the

Late Permian Late or LATE may refer to: Everyday usage * Tardy, or late, not being on time * Late (or the late) may refer to a person who is dead Music * ''Late'' (The 77s album), 2000 * Late (Alvin Batiste album), 1993 * Late!, a pseudonym used by Dave Groh ...

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

. The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

''Scalopodon tenuisfrons'' was named in 1999 from the Kotelnichsky District of

Kirov Oblast Kirov Oblast ( rus, Кировская область, p=ˈkʲirəfskəjə ˈobləsʲtʲ) is a federal subject of Russia (an oblast) located in Eastern Europe. Its administrative center is the city of Kirov. As of the 2010 census, the population ...

. ''Scalopodon'' is known from a single fragmentary

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

specimen including the back of the skull, the left side of the lower jaw and isolated postorbital and prefrontal bones. The skull was found in the ''Deltavjatia'' Assemblage Zone, which dates back to the early

Wuchiapingian In the geologic timescale, the Wuchiapingian or Wujiapingian (from in the Liangshan area of Hanzhong, Shaanxi Province ) is an age or stage of the Permian. It is also the lower or earlier of two subdivisions of the Lopingian Epoch or S ...

about 260 million years ago. Distinguishing features of ''Scalopodon'' include narrow

frontal bone In the human skull, the frontal bone or sincipital bone is an unpaired bone which consists of two portions.'' Gray's Anatomy'' (1918) These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bo ...

s and a distinctive

sagittal crest A sagittal crest is a ridge of bone running lengthwise along the midline of the top of the skull (at the sagittal suture) of many mammalian and reptilian skulls, among others. The presence of this ridge of bone indicates that there are excepti ...

along the parietal region at the back of the skull. ''Scalopodon'' was originally classified in the family

Scaloposauridae Baurioidea is a superfamily (zoology), superfamily of therocephalian therapsids. It includes advanced therocephalians such as ''Regisaurus'' and ''Bauria''. The superfamily was named by South African people, South African paleontologist Robert Br ...

, and was the first scaloposaurid found in Russia (scaloposaurids are also known from southern Africa and Antarctica). More recent studies of therocephalians have found scaloposaurids like ''Scalopodon'' to be juvenile forms of larger therocephalians and do not consider Scaloposauridae to be a valid group. ''Scalopodon'' and most other scaloposaurids are now classified as basal members of Baurioidea.

References

Baurioidea Therocephalia genera Lopingian synapsids of Europe Fossils of Russia Fossil taxa described in 1999 {{paleo-therapsid-stub