Sifrhippus

Sifrhippus is an extinct genus of equid containing the species S. sandrae. Sifrhippus is the oldest known equid, living during the early Eocene. Its fossils were discovered in the Bighorn Basin of Wyoming.

==Description== Sifrhippus would have looked quite different to modern horses, being more slender and much smaller, with a relatively small head and longer hindlimbs. Its body was built to leap around the forest undergrowth instead of galloping on open grasslands like later equids. Individuals likely weighed between ; the size variance, according to one theory, depended on the warmth of the climate.