Diceratherium
Diceratherium (meaning "two horned beast") is an extinct genus of rhinoceros 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

Taxonomy
 
 
Diceratherium was named by Marsh (1875) based on the type species Diceratherium armatum. It was assigned to Rhinocerotidae by Marsh (1875) and Carroll (1988); to Diceratheriinae by Prothero (1998); to Aceratheriinae by Weidmann and Ginsburg (1999); and to Teleoceratini by Sach and Heizmann (2001). Diceratherium had two horns side by side on its nose. "Blue Lake Rhino" 

A full-body mold of a Diceratherium exists as an impression in a cliff on the shore of Blue Lake near Coulee City, Washington. The impression is a lava cast that is thought to be of a mature individual that died in a shallow lake and was rapidly buried by a basalt flow during the mid-Miocene (about 15 million years ago), creating a three-dimensional mold of its body. The mold formed a rhinoceros-shaped cave on exposed rocks belonging to the Columbia River Basalt Group, which was first discovered by two Seattle couples searching for petrified wood in 1935, who also discovered remnant bones of the animal. A replica of the "rhinoceros cave" was created by researchers from the University of California Museum of Paleontology in 1948 and later donated to the Burke Museum, where it is on display. References

Serravallian genus extinctions
Oligocene mammals of North America
Cenozoic mammals of Europe
Cenozoic mammals of Asia
Oligocene rhinoceroses
White River Fauna
Chattian genus first appearances
Miocene rhinoceroses
Fossil taxa described in 1875