Hagerman horse fossil skeletons; public domain image on Wikipedia.
Official State Fossil of Idaho
The Hagerman horse fossil was designated the official state fossil of Idaho in 1988. All State Fossils
3.5 million year old sediments at the Hagerman Fossil Beds National Monument in Idaho contain the world's richest known fossil deposits from the late Pliocene epoch (200 horse skeletons have been recovered at the Hagerman Fossil Beds, 20 of which are complete).
The Hagerman horse (Equus simplicidens) is the oldest known representative of the modern horse genus Equus (which includes horses, donkeys, and zebras) and is believed to be more closely related to the living Grevy's zebra in Africa than our modern horse. Idaho also recognizes an official state horse.
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