Uintatherium, is an extinct genus of herbivorous mammal

Mammal

Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

 that lived during the Eocene

Eocene

The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...

 epoch, which includes a single species currently recognized, U. anceps. They were similar to today's rhinoceros

Rhinoceros

Rhinoceros , also known as rhino, is a group of five extant species of odd-toed ungulates in the family Rhinocerotidae. Two of these species are native to Africa and three to southern Asia....

 both in size and in shape, although they are not closely related. Their fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

s are the largest and most impressive of the finds at the excavation of Fort Bridger

Fort Bridger

Fort Bridger was originally a 19th century fur trading outpost established in 1842 on Blacks Fork of the Green River and later a vital resupply point for wagon trains on the Oregon Trail, California Trail and Mormon Trail. The Army established a military post here in 1858 during the Utah War until...

 in Wyoming, and were a focal point of the Bone Wars

Bone Wars

The Bone Wars, also known as the "Great Dinosaur Rush", refers to a period of intense fossil speculation and discovery during the Gilded Age of American history, marked by a heated rivalry between Edward Drinker Cope and Othniel Charles Marsh...

 between Othniel Charles Marsh

Othniel Charles Marsh

Othniel Charles Marsh was an American paleontologist. Marsh was one of the preeminent scientists in the field; the discovery or description of dozens of news species and theories on the origins of birds are among his legacies.Born into a modest family, Marsh was able to afford higher education...

 and Edward Drinker Cope

Edward Drinker Cope

Edward Drinker Cope was an American paleontologist and comparative anatomist, as well as a noted herpetologist and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested in science; he published his first scientific paper at the age of nineteen...

.