Irdin Manha Formation

The Irdin Manha Formation is a palaeontological formation from the Eocene located in Inner Mongolia, China, a few kilometres south of the Mongolian border (43.7°N 112.0°E / 43.7; 112.0, paleocoordinates 45.2°N 105.7°E / 45.2; 105.7).

U.S. paleontologists Henry Fairfield Osborn and Roy C. Andrews discovered two premolars on the site in 1923, and Osborn 1924 assigned the specimen to the new genus Eudinoceras because he believed it to be related to "Dinoceras" (now known as Uintatherium). Within a decade, however, as more complete specimens were recovered, the animal was identified as a Mongolian relative to the North American pantodont Coryphodon.