''Equus niobrarensis'' (or commonly, Niobrara horse) is an extinct

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of '' Equus'', the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

that includes the

horse The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million yea ...

. ''E. niobrarensis'' may be synonymous with ''

Equus scotti ''Equus scotti'' (translated from Latin as Scott's horse, (2003) ''Annotated Bibliography of Quaternary Vertebrates of Northern North America: With Radiocarbon Dates'', University of Toronto Press, 539 pages named after vertebrate paleontologis ...

''. It was "stout-legged" and belonged to the "big horses" category as defined by M. C. Winans. The skull of the horse was noted as being broader than

Equus caballus The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 million y ...

Distribution

''E. niobrarensis'' was native to North America and commonly found in western North America and dates to the late Pleistocene.

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s of ''E. niobrarensis'' were discovered at Dry Cave in

Wisconsin Wisconsin () is a state in the upper Midwestern United States. Wisconsin is the 25th-largest state by total area and the 20th-most populous. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake M ...

. Another mention of an ''E. niobrarensis'' discovery was in Skeleton Cave,

Oregon Oregon () is a state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. T ...

References

{{Taxonbar, from=Q48849114 Equus (genus) Endemic fauna of the United States