The species was first named in 1867, with the type specimen being IGF 560, a skull with a now lost (but preserved as a cast) associated mandible collected from Terranuova Bracciolini in Italy.

[7] The feet are monodactyl, the head is large and elongated and has an undulated top profile in side-view, the nasal notch is deeply incised.

The metapodial bones of the foot are proportionally elongate and robust, with the central digit having a massive morphology, with a large v-shaped muscle scar.

[1] Equus stenonis is known from remains found across Europe, from the Iberian Peninsula to Greece, as well as the Dmanisi site in Georgia, spanning part of the Early Pleistocene, the oldest remains dating to approximately 2.5 million years ago, while the youngest dates are uncertain, ranging from 1.8-1.3 million years ago.

[1] Dental wear patterns of the species' teeth fromthe Coste San Giacomo locality in Italy suggest that E. stenonis was a grazer.