A fossil from an extinct relative of the rhinoceros, Telataceras, set the record for highest vertebrate fossil found in Utah.
A jawbone with three molars was found 10,000 feet up Thousand Lake Mountain in Wayne County, Utah. Geologists from the Utah Geological Survey found the fossil while mapping rock layers in the mountain in 2005.
On another expedition in 2006, the geologists found a portion of the skull of another extinct mammal, a brontothere known as Duchesneodus uintensis. The fossils were embedded in sand and gravel that were likely laid down by a river.
Finding the two fossils in the same sediment layer suggested to the scientists that they are around 42 to 37 million years old, from a period known as the Duchesnean Land Mammal Age, during the Eocene Age.
The researchers, led by Donald Deblieux of the Utah Geological Survey, believe that certain features of the brontothere fossil may mean it is a new species.