This is a mural at the Smithsonian Museum, showing how the Great Plains would have looked about 3 million years ago.
The critters here include Amebelodon (the elephant-lookin’ things in the middle),
Neohipparion (tiny horse),
Synthetoceras (antelopes with the antlers in their noses),
Teleoceras (an American rhino),
Merycodus (prong-horned antelopes),
Epigaulus (“horned gopher”),
Hypolagus (giant rabbits), and
Cranioceras (the spikier antelope there).