English: Syndyoceras cooki Barbour, 1905 - fossil mammal skeleton from the Miocene of Nebraska, USA. (public display, Nebraska State Museum of Natural History, Lincoln, Nebraska, USA)
From museum signage:
Four-horned ruminant
Syndyoceras belongs to an extinct group of artiodactyls. Fossil remains of this ruminant have been found only in Nebraska and Wyoming, and the specimen from Nebraska displayed here is the only mounted specimen recorded. Syndyoceras is a distant relative of the modern antelope, giraffe, deer, and cow. The male is unusual in that is possesses four horns, which probably were very effective for protection.
Classification: Animalia, Chordata, Vertebrata, Mammalia, Artiodactyla, Ruminantia, Protoceratidae
Stratigraphy: Daimonelix beds, Marsland Formation, Middle Miocene
Locality: bluffs at the James Cook Ranch, western side of the Niobrara River, near the town of Agate, Sioux County, northwestern Nebraska, USA
See info. at:
en.wikipedia.org/wiki/Syndyoceras