Merychippus
![M. sejunctus front and back feet (right) and M. sphenodus lower jaw fragment](/Images/godic/202501/26/Anchitherium4641.jpg")
Merychippus is an extinct proto-horse of the family Equidae that was endemic to North America during the Miocene from 20.43—10.3 Ma living for approximately 10.13 million years.
It had three toes on each foot and is the first horse known to have grazed. Its name means "ruminant horse", but current evidence does not support Merychippus ruminating.