Equus niobrarensis (or commonly, Niobrara horse)[1] is an extinct species of Equus, the genus that includes the horse. E. niobrarensis may be synonymous with Equus scotti.[2] It was "stout-legged" and belonged to the "big horses" category as defined by M. C. Winans.[2] The skull of the horse was noted as being broader than Equus caballus.[3]
E. niobrarensis was native to North America and commonly found in western North America and dates to the late Pleistocene.[4] Fossils of E. niobrarensis were discovered at Dry Cave in New Mexico.[5] Another mention of an E. niobrarensis discovery was in Skeleton Cave, Oregon.