Oligocene rhinoceroses

Paraceratherium is an extinct genus of hornless rhinocerotoids belonging to the family Paraceratheriidae. It is one of the largest terrestrial mammals that has ever existed and lived from the Early to Late Oligocene epoch (34–23 million years ago). The first fossils were discovered in what is now Pakistan, and remains have been found across Eurasia between China and the Balkans. Paraceratherium means "near the hornless beast", in reference to Aceratherium, the genus in which the type species P. bugtiense was originally placed.

thumb|Skeletal reconstruction of Hyracodon Hyracodon ('hyrax tooth') is an extinct genus of perissodactyl mammal from the White River Formation.

Metamynodon is an extinct genus of amynodont that lived in North America (White River Fauna) and Asia from the late Eocene until early Oligocene, although the questionable inclusion of M. mckinneyi could extend their range to the Middle Eocene. The various species were large, displaying a suit of semiaquatic adaptations more similar to those of the modern hippopotamus, despite their closer affinities with rhinoceroses.

Subhyracodon (Latin: "below the genus Hyracodon") is an extinct genus of hornless rhinocerotids.

Diceratherium (meaning "two horned beast") is an extinct genus of rhinocerotid native to North America during the Oligocene through Miocene living from 33.9 to 11.6 mya, existing for approximately . Mass estimates for the type species, D. armatum average around

Urtinotherium (meaning "Urtyn beast" in Ancient Greek) is an extinct genus of paracerathere mammals. It was a large animal that was closely related to Paraceratherium, and found in rocks dating from the Late Eocene to Early Oligocene period. The remains were first discovered in the Urtyn Obo region (now Dorbod Banner, Ulanqab) in Inner Mongolia, which the name Urtinotherium is based upon. Other referred specimens are from northern China.

thumb|left|Life restoration Cadurcodon is an extinct genus of amynodont that lived during the Late Eocene to the Oligocene period. Fossils have been found throughout Mongolia and China. It may have sported a tapir-like proboscis due to the distinct features found in fossil skulls.

Ronzotherium is an extinct genus of perissodactyl mammal from the family Rhinocerotidae. The name derives from the hill of 'Ronzon', the French locality near Le Puy-en-Velay at which it was first discovered, and the Greek suffix 'therium' meaning 'beast'. At present 5 species have been identified from several localities in Europe and Asia, spanning the Late Eocene to Upper Oligocene (37 - 23 million years ago).

Eggysodon is an extinct genus of odd-toed ungulate belong to the rhinoceros-like family Eggysodontidae. It was a small, ground-dwelling browser, and fossils have been found in Oligocene deposits throughout Europe. Eggysodon may have been related to Preaceratherium, and both had tusklike canines and smaller, and fewer, incisors.

Diaceratherium is an extinct genus of rhinocerotid from the Oligocene and Early Miocene of Eurasia.