Dvinosaurus is an extinct genus of amphibious temnospondyls localized to regions of western and central Russia during the middle and late Permian, approximately 265-254 million years ago.

[2] Its discovery was first noted in 1921 by Russian paleontologist Vladimir Prokhorovich Amalitskii in a posthumously published paper that documents the findings of a site in Russia's Arkhangelsk District.

[4] Dvinosaurus is thought to have been a gill-breathing, fully-aquatic tetrapod, characterized by a large, triangular head, short limbs, and a long powerful tail.

[7] Finally, prominent spinous processes found in the more caudal vertebrae indicate that Dvinosaurus possessed a powerful tail that, in combination with its short, muscular limbs, could propel it rapidly toward its prey.

[7] As a byproduct of its orbits being situated on the top of its head, it is thought that Dvinosaurus preferred deeper rivers as this would allow for improved predation of the fish in the upper water levels.

[7][8] Within the Vyazniki locality itself, Dvinosaurus is thought to have been a mid-level predator, preying upon invertebrates, paleonisciforms, hybodontiformes, and larval forms of other aquatic tetrapods, while conversely being hunted by chroniosuchians such as Bystrowiana.

[8] Interestingly, upon analysis of Dvinosaurus’ characteristics it was determined that this genus displayed a mixture of both primitive and progressive traits in relation to its larger subclass, labyrinthodonts.

While its distribution is restricted to regions containing rivers such as the Volga and Northern Dvina, it is thought that these localities may have undergone significant geographical shifting during continental drifts approximately 200 million years ago.

[11] Several close relatives of Dvinosaurus, most notably Brachyopidae such as Brachyops, Bothriceps, and Batrachosuchus, inhabited regions of Gondwana, a supercontinent comprising present day Africa, India, South America, Australia, and Antarctica.

[11] It is feasible that these relatives and Dvinosauran precursors dwelled on this supercontinent before migrating north to the regions where Dvinosaurus ultimately appears in the fossil record.

[11] There are currently 45 locations across Eastern Europe at which Dvinosaurus remains have been documented, most of which are found in the Arhangelsk district in northwestern Russia bordering the White Sea in the Arctic Ocean.

[8] Dvinosaurus belongs to the larger clade Dvinosauria, which also includes the taxa Trimerorhachis, Neldasaurus, Perryella, Acroplous, Isodectes, Slaugenhopia, Kourerpeton, Tupilakosaurus, and Thabanchuia.