Haringtonhippus francisci

Haringtonhippus francisci is an extinct equine of Pleistocene North America and the only species of its genus, first described in 1915 by Oliver Perry Hay as Equus francisci. These stilt-legged horses had slender lower limb bones, unlike the stout-legged caballine true horses that lived alongside them. Fossils range from southern Mexico to southern South Dakota and Alberta, Canada, at sites such as Gypsum Cave and Natural Trap Cave. Body mass is estimated at about 167 to 251 kilograms, and the third metatarsals resemble those of asses. It was probably a grazer. A 2017 DNA study placed it outside the living members of Equus, though some authors keep it in that genus, and it became extinct around 12,000 years ago.