''Dvinia'' is an extinct genus of cynodonts found in the Salarevo Formation of Sokolki on the

Northern Dvina River The Northern Dvina (russian: Се́верная Двина́, ; kv, Вы́нва / Výnva) is a river in northern Russia flowing through the Vologda Oblast and Arkhangelsk Oblast into the Dvina Bay of the White Sea. Along with the Pechora River ...

near

Kotlas Kotlas (russian: Ко́тлас) is a town in Arkhangelsk Oblast, Russia, located at the confluence of the Northern Dvina and Vychegda Rivers. Population: Kotlas is the third largest town of Arkhangelsk Oblast in terms of population (after A ...

in Arkhangelsk Oblast,

Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...

. It is the only known member of the family Dviniidae. Its fossil remains date from the

Late Permian Late may refer to: * LATE, an acronym which could stand for: ** Limbic-predominant age-related TDP-43 encephalopathy, a proposed form of dementia ** Local-authority trading enterprise, a New Zealand business law ** Local average treatment effect, ...

and were found with ''

Inostrancevia ''Inostrancevia'' is an extinct genus of carnivorous therapsids, containing the largest members of gorgonopsians, predators characterized by long, saber-tooth-like canines. The various species inhabited European Russia during the Upper Tatar ...

'', ''

Scutosaurus ''Scutosaurus'' ("shield lizard") is an extinct genus of pareiasaur parareptiles. Its genus name refers to large plates of armor scattered across its body. It was a large anapsid reptile that, unlike most reptiles, held its legs underneath its ...

'' and '' Vivaxosaurus''. ''Dvinia'' was a small omnivore possessing a large temporal opening typical of advanced therapsids, with a thin

postorbital bar The postorbital bar (or postorbital bone) is a bony arched structure that connects the frontal bone of the skull to the zygomatic arch, which runs laterally around the eye socket. It is a trait that only occurs in mammalian taxa, such as most strep ...

separating the eye from the muscle attachment. As a cynodont, it was closely related to mammals. The dentition consisted of a set of small

incisor Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, wher ...

s followed by 2

canines Canine may refer to: Zoology and anatomy * a dog-like Canid animal in the subfamily Caninae ** ''Canis'', a genus including dogs, wolves, coyotes, and jackals ** Dog, the domestic dog * Canine tooth, in mammalian oral anatomy People with the surn ...

and 10-14

postcanine Cheek teeth or post-canines comprise the molar and premolar teeth in mammals. Cheek teeth are multicuspidate (having many folds or tubercles). Mammals have multicuspidate molars (three in placentals, four in marsupials, in each jaw quadrant) and ...

References

External links

''Dvinia'' skull model and illustrations

Prehistoric cynodont genera Lopingian synapsids of Europe Permian Russia Fossils of Russia Fossil taxa described in 1922 Taxa named by Vladimir Prokhorovich Amalitskii {{Paleo-Therapsid-stub

See also

References

Further reading

External links