[3] The best known Elasmotherium species, E. sibiricum, sometimes called the Siberian unicorn,[4] was among the largest known rhinoceroses, with an estimated body mass of around 4.5 tonnes (9,900 lb), comparable to an elephant, and is often conjectured to have borne a single very large horn.
Elasmotherium was first described in 1808-1809 by German/Russian palaeontologist Gotthelf Fischer von Waldheim based on a left lower jaw, four molars, and the tooth root of the third premolar, which was gifted to Moscow University by princess Ekaterina Dashkova in 1807.
In 1877, German naturalist Johann Friedrich von Brandt placed it into the newly erected subfamily Elasmotheriinae, separate from modern rhinos.
[6] The genus is known from hundreds of find sites, mainly of cranial fragments and teeth, but in some cases nearly complete skeletons of post-cranial bones, scattered over Eurasia from Eastern Europe to China.
[14] Hypsodonty, a dentition pattern where the molars have high crowns and the enamel extends below the gum line, is thought to be a characteristic of Elasmotheriinae,[15] perhaps as an adaptation to the heavier grains featured in riparian zones on riversides.
[8] The Khaprov is in the Middle Villafranchian, MN17, which spans the Piacenzian of the Late Pliocene and the Gelasian of the Early Pleistocene of Northern Caucasus, Moldova and Asia and has been dated to 2.6–2.2 Ma.
[20] E. caucasicum was first described by Russian palaeontologist Aleksei Borissiak in 1914, who said it apparently flourished in the Black Sea region as a member of the Early Pleistocene Tamanian Faunal Unit (1.1–0.8 Ma, Taman Peninsula).
[16] E. sibiricum, described by Johann Fischer von Waldheim in 1808 and chronologically the latest species of the sequence appeared in the Middle Pleistocene, ranging from southwestern Russia to western Siberia and southward into Ukraine and Moldova.
[26] Like other rhinos, Elasmotherium had two premolars and three molars for chewing, and lacked incisors and canines, relying instead on a prehensile lip to strip food.
[citation needed] Elasmotherium is traditionally thought to have had a keratinous horn, indicated by a circular dome on the forehead, with a 13-centimetre (5-inch) deep, furrowed surface, and a circumference of 90 cm (3 feet).
[34] Modern hypsodont hoofed mammals are generally grazers of open environments,[35] with hypsodonty possibly an adaptation to chewing tough, fibrous grass.
[28] Elasmotherium also displays euhypsodonty (evergrowing teeth), which is typically seen in rodents,[38] and dental physiology could have been influenced by pulling up food from moist, grainy soil.
[40] This timing is roughly coincident with the Pleistocene extinction, during which many mammal species with body weights greater than 45 kilograms (99 lb) died out.