Horses originated in America several million years ago, from there they spread into the Old World where they multiplied and survived. Their American relatives became extinct. Horses were re-introduced into America by the Europeans after 1492. That is the official story.
There may be another one:
Native American Horses
There were two kinds of horses living in Patagonia before the arrival of Europeans; and they are believed to have become extinct at the end of the last Ice Age some 8,000 years ago.
One of them, the primitive Hippidion which appeared about 2.5 million years ago (Ma.), reached Tierra del Fuego; the other, a modern Equus which appeared only about 1 Ma, extended its range to northern Patagonia.
Both co-existed with men, who hunted them and their extinction is quite a mystery since the virtually identical Old World horses introduced by the Spaniards flourished in the same environment.
This has led some authors believe that not all of these horses died, and that some managed to survive until the arrival of the European horses “influenc[ing] the morphology and other sui generis features of the current Creole horse” by interbreeding with them.
In other words, they survived and mated with their European relatives.
Notice the spotted red and white appearance of the Hippidion's coat (in all the depictions that I found, it is represented with a spotted coat).
French engineer Narcise Parchappe reported in 1828 that “it is notable that nearly all the Indian’s horses are picazos (red and white) and stained in a strange manner; while this variety is very rare among the Creoles”. As these colors were also rarely found in the large herds of wild horses; he thought that the natives selectively bred these strange colored animals.
Actually, these horses were not “picazos” but “overos” of a very special kind. Picazos known as piebald, have a black base coat, while the overos have a solid color with splashes of white.
The native’s variety of overo is known as “overo manchado”; in Spanish, manchado means stained in the sense of something “splattered on”. This color has only cropped up in Argentina in horses from different breeds. The pattern is also atypical and is not related to the spots of any other horse breeds (like apaloosa, sabino or chubari).
Furthermore, it appears as a sudden mutation in animal breeds that don’t have spots such as Criollo, Hackney, Arab and Thoroughbred, this would imply that they could not be selectively bred by the natives.
The pre-Hispanic horses could have introduced this peculiar coat color into the genetic pool of the horses introduced by the Spaniards; and it now appears randomly.
Regarding southern Patagonian horses, Musters wrote during his 1870 journey through Patagonia that “near Port San Julian […] there are numbers of wild ponies, about the size and make of a shelty, which the children play with”.´ Could these ponies have been a remnant group of adult Hippidion?
Hr also noted that the Aonikenk horses were “altered […] to a considerable degree from the original [Spanish] race”, and that though they were smaller than them, their heads and legs were larger. This perhaps reflects not an alteration of pure European horses but their interbreeding with pre-Hispanic horses.
Is there other evidence of these surviving prehistoric horses?
Yes, we have the testimony of Spanish conquistador, Captain Juan Fernández who was the first to explore Nahuel Huapi region in 1621. He wrote that the natives on the Limay River had horses.
It could be argued that they had obtained them from the Spanish settlements in southern South America (dating back to the 1530s), which would have given them at least 90 years to come across, tame and master these new beasts.
However there are pre-Hispanic horses in rock art depictions; at Nahuel Huapi Lake one represents a horse riding warrior; it was discovered by Asbjorn Pedersen in 1960.
Pedersen wrote that he was amazed by these horsemen but was even more surprised when he “later noticed that these paintings could be the first tangible manifestation of an extinct fauna, since they do not represent the common horse (Equus caballus), but the American horse (Equus rectidens)”.
These depictions are not contemporary to the Spanish Conquest but ancient because according to D’Orbigny, the Patagonian natives’ “drawings have the uniqueness of never representing animal figures”. This was an exclusive trait of the “ancient” Indians.
Click to See the rock art depicting ancient American horses.
Mancha was a Creole horse, that was bred from a group of horses purchased by Dr. Emilio Solanet in Chubut. They had belonged to Tehuelche chief Liempichún.
He had the spotted coat of a Manchado horse. He is famous because he rode from Buenos Aires to Washington DC (16,000 km - 10,000 mi.) between 1925 and 1928.
Notice the different build of the Creole (Mancha in the bottom photograph) in comparison to a thoroughbred (upper photograph). They are shorter and sturdier. Also note the domed nasal bone on Mancha -a feature that characterizes Hippidon.
The intriguing possibility of surviving prehistoric Megafaunal Age horses is very exciting. Perhaps science will unveil the mystery by finding recent remains of both creatures.
 Mac-Leod Silva, C., (1999). Estudio de los equinos carretoneros…. Univ. Nac. de Chile. pp. 6 [Thesis]. Citing: Evans, W., et al., (1979). El Caballo. Zaragoza: Editorial Acribia.
 D’ Orbigny, A. Op. Cit. pp. 79.
 Wellman, K. The Sabino Pattern and The Myth of the True-Breeding White/Albino Horse.
 Zubizarreta, H. Pelajes Equinos Genética y Transmisión.
 Musters, C. Op. Cit. pp.130+
 Fernández, M., (2006). Economía y sistemas de asentamiento aborigen en la cuenca del río Limay. Mem. am., ene./dic. 2006, no.14, p.37-73. Citing: Vignati, M., (1939). Los indios poyas. Notas del Museo de La Plata, 4 (Antropología, Nº 12): 211-44. B. Aires. pp. 238-239.
 Houssay, A., (1971). El caballo de guerra en la iconografiá argentina.. B. Aires: Ejército Argentino, Comando y Dirección General de Remonta y Veterinaria. pp. 111.
 Pedersen, A., (1979). Las pinturas rupestres del parque nacional Nahuel Huapi. Anales de Parques Nacionales XIV (1978): 7-43.
 D’Orbigny, A. Op. Cit. pp. 326 and 327.
 Aimé Tschiffely - Long Rider
Another version on extant "native American Horses" is the Mormon one Here (I am not a Mormon).
Copyright 2009 by Austin Whittall ©