Equus lenensis

Equus lenensis
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Perissodactyla
Family:	Equidae
Genus:	Equus
Species:	E. lenensis
Binomial name
Equus lenensis Russanov, 1968[1]

Equus lenensis, the Lena horse, is an extinct species of horse from the Late Pleistocene and Holocene of Siberia,^[2][3][4] Some sources have considered it a subspecies of the wild horse.^[5]

A notable Lena horse specimen was found in Batagaika crater in Russia^[3] which was preserved almost completely intact, and with liquid blood within its preserved veins.^[3] The specimen was hypothesized to be about two months old when it died and was uncovered nearly 40,000 years later by scientists in 2018 because of the melting permafrost caused by rising temperatures in the region.^[6]

Another specimen from the mid-Holocene known as the Yukagir horse was found in another thawing deposit in Yakutia, Russia.^[7]

Characterized by their small average size, Equus Lenensis lived in cold steppe-tundra environments in North Siberia.^[8] They ate primarily grass, but evidence exists of browse plants (shrubbery or other high-growing plants) as well as non-herbaceous plants (woody-stemmed plants) in their diets.^[8]

Genetic studies show that E. lenensis does not descend from the last common ancestor of living horses, and is estimated to have diverged from them approximately 115,000 years ago, though it is more closely related to modern horses than either are to a highly divergent horse lineage from the Late Pleistocene of the Iberian Peninsula. The youngest remains of the species date to 5,000 years Before Present (~3000 BC).^[4]

Most extinct horse specimens from this time period in Northeast Siberia have been classified as Equus lenesis but may actually belong to many closely related allospecies of prehistoric horses in the area.^[4]