THE ORIGIN, DIFFUSION AND LANDSCAPE

IMPACT OF THE HORSE

by Mark Hogben

The ancestors of the horse can be traced back, from skeletal remains found in America, to the beginning of the Tertiary period. During this sixty million year era, the most noticeable changes that took place in the horse included it's size, teeth and feet. The bodily changes that took place were so great that when the fossil bones of one of the early ancestors; a small rabbitlike creature subsequently dubbed the Hyracotherium; was discovered, it's relationship to the modern horse was not even suspected. It was not until several intermediate skeletons were discovered that the true place of the Hyracotherium was recognized (Denhardt, 1948).

With the exception of the Hyracotherium, the Eohippus is the oldest known horse. It was no larger than a dog and it's teeth were small and lowcrowned, adapted for chewing on soft vegetation. It probably feed on the sandy and grassy areas of the lowlands which bordered the underbrush of densely forested regions. Eohippus had four toes on the front foot and three on the hind foot. The tips of it's toes were small hoofs similar to those of later horses. All four toes reached the ground, but most of the weight was supported by the largest (Denhardt, 1948).

Following the Eohippus was the Mesohippus. Still no larger than an average size dog, it was characterized by increased skull and brain size. The teeth were larger and uncrowned making reasonable the assumption that they inhabited the stream borders where they fed on succulent plants. Remains of Mesohippus have been found most abundantly in the great Bad Lands of South Dakota

and northeastern Colorado. The outer toes were completely lost, and the weight of the animal was borne primarily by the centre digit, although the side toe rested on the ground (Ridgeway, 1972).

The horse in the next stage is called the Parahippus. This stage is characterized by a noticeable growth in the cannon bone. The central toe supported most of it's weight, but the extra toes remained even though they did not touch the ground. These developments indicate an increased ability for speed which was an adaptive characteristic in the horse's fight for survival in the plains country (Ridgeway, 1972).

Even more like our modern horse was Merychippus. Typical plains conditions were prevalent during the era of Merychippus. Hackberries, willows, cottonwoods and sycamores bordered the streams, and many small lakes were formed in the broad river valleys. The teeth of the Merychippus had become higher and extended well into the jaws, an adaptation arising from the abrasive effects of the dry bunch grass and sand that had to be taken into the mouth. It's side toes receded and shifted back toward what is now called the fetlock. These animals were comparable in size to a small pony (Ridgeway, 1972).

Pliohippus is a direct predecessor of our modern day horse. The skull was now even larger; long, curved teeth extended three inches up into the head; and the side toes had all but disappeared. Pliohippus was followed by Equus, the horse of the Glacial epoch which is similar in most respects to the modern horse (Ridgeway, 1972).

Eohippus and Equus are separated by a period of approximately sixty million years. During these long ages the early horse was extremely abundant, and at least two migrations took place from the New world to the Old. Of these migrations, only the second group survived. In the Americas the original stock died out completely (Walsh, 1869).

Nomadic by nature, the Eohippus wandered up through Alaska into Asia; the Bering Strait did not exist at that time and the two continents were connected. From the northeast corner of Asia, the horses migrated southwest until they reached Europe where they concentrated in great numbers. Early in the nineteenth century, geologists exploring the rock strata of France, Switzerland and Belgium found a profusion of ancient horse bones there. Because the skeletons resembled that of the Eohippus and because the bones were found in rock strata whose age corresponded to the time period in which Eohippus existed, it was inferred that this migration took place very early in the history of the horse (Pocock, 1917).

One of the descendants of the first European horse was the Paloplotherium. This ancient horse of Europe was first to lose one of it's extra toes and was also relatively large. Teeth changes show that this horse gave up eating bushes, shrubs and plants and instead ate grasses. Moreover, the breed roamed around in herds which was a characteristic of the much later wild horses of the United States and of Asia. Despite all this progress, the vast and varied European horses died out for reasons unknown.

Thus, there were no more horses in Europe until the horses of America again migrated three over thirty million years later (Pocock, 1917).

There were, however, still horses in North America. The original line of Eohippus was prospering at a slow and even rate. In fact, the Eohippus in North America persisted right up to the present, by which time they had become Equus. The primary reason why Equus radiated to all corners of the earth was that it had to keep on the move because of the glaciers (Law, 1980).

Five of these ice sheets, at intervals of several thousand years, pushed their way down over the continent, each retreating during the glacial intervals when the world was gradually warming again. When the first cold spells descended upon the continent and destroyed much of the horse's food, a good many of the latter instinctively migrated across Asia not only to Europe but also to Africa. These are the horses that founded the zebra race in Africa (Law, 1980).

Of the horses that remained on the American continent, some migrated to South America, where even after successive glaciers there was still an abundance of food. Nevertheless, for some mysterious reason, all the horses died about half a million years ago. The probability is that they died from a disease that was not restricted to horses. Those horses who had not migrated to the southern hemisphere at all, died for lack of food (Forester, 1857).

Eventually, after the horse stock had fanned out over Asia, Europe and Africa, Palaeolithic man evolved. To meat-hungry men of the Stone Age, horses answered nearly every food need. But it was with the domestication of Equus that the destiny of both

horses and mankind took their most important turns and their impact on the landscape was irrevocably altered.

It's imagined that with the captivity of horses, better methods were found to control the animals beginning with bone bits and reins, eventually leading to the creation of wheels to produce chariots. It is generally agreed that early man hitched horses to chariots or chariot-like vehicles long before riding them as steeds, perhaps due to the fact that the small size of the Asiatic strains would make hitching more practical than riding. The birth-place of the chariot horse was ancient Assyria. The chariot itself is the oldest vehicle known to man, having been invented at least as early as 2000 B.C. The introduction of the chariot created the need for roads between densely populated areas in order to increase the speed and volume of both trade and information. Accompanying the increased access to distant places and available resources came mankind's insatiable desire for conquest (Vernon, 1939).

The horse was first employed as an instrument of war by pulling a war chariot rather than by serving as a mount. Employment of the horse was the greatest advancement in the science of military organization in the history of man as a fighting animal, but it was not until Alexander the Great came, did the horse become so pivotal in the business of war (Vernon, 1939).

The battle that rendered the alliance between Equus and man the most vivid was at the river Hydaspes, where the prince of India confronted the Macedonians with a cavalry of four thousand, aided and abetted by two hundred elephants, three hundred chariots and thirty thousand infantry. Since Alexander had only nine thousand foot soldiers and five thousand cavalry, he determined to make it a battle of horses. By judicious use of his cavalry, he was prepared to defeat a host ten times his own strength.

When Alexander arrived on the scene, the Indian prince already had his army lined up for a defensive battle, probably having overestimated Alexander's strength. It did not take Alexander long to realize, first, that his own nine thousand infantry would be of no initial use in attacking the Prince's vast horde; and, second, that he could never expect his cavalry to charge the long front of elephants and charioteers.

The first thing that Alexander did was to manoeuvrer his cavalry all over the plain, so that the Prince would be used to the sight of his horses being on the move. In these preliminary movements, the seven hundred horses on Alexander's left flank, instead of turning back to the line, kept marching in a wide swing behind the hills on the Prince's right. The Prince, busy watching the main body of Alexander's cavalry on the latter's right, did not notice them. Alexander then sent his comparatively small infantry slowly toward the Prince's forces in another attempt to divert the enemy's attention, this time from the bulk

of his cavalry which by now was swinging far to Prince's left to attack his flank.

When Alexander's first light horses let a stream of arrows fly to give the heavier horses a chance to get around the flank, the Prince realized what was happening. He pivoted his left flank cavalry backwards to face Alexander's force, while his right flank cavalry was ordered to hurry behind the lines to reinforce it, thus leaving the presumably unthreatened right flank unprotected. The Prince's chariots, heavy and cumbersome, could not possibly turn around to face Alexander, so all they could do is charge out onto the already evacuated plain.

In the meantime, the seven hundred horses sent out by Alexander came around the mountain to find that the enemy's right cavalry had moved off to the left in order to reinforce, so they marched straight into the enemy infantry's right wing, broke it up hopelessly and sent the elephants running ahead to join the useless chariots. Then, still intact, it hurried over to the right side to engage in battle from behind with the Prince's cavalry while it was being attacked from the front by Alexander and the bulk of his cavalry. As a result the battle of Hydaspes was fought and won by the horses, as a whole host of foot soldiers stood uselessly by (Vernon, 1948).

The eight hour battle has been neither surpassed nor equalled for the brilliant performance of horses in the annals of military history. Alexander buried the body of his horse 'Bucephalus' on the banks of the river Hydaspes and a city, named Bucephala arose to honour the horse (Vernon, 1948).

This anecdote involving Alexander the Great and his horse illustrates the phenomenal impact that the domestication and military utilization of Equus had on the landscape. Bucephala

stands for more than a monument honouring the fallen horse of a great leader, it stands for the essential role that the horse played in the creation of political limits and borders, some of which still exist today as a consequence of the involvement of Equus in battles long since forgotten.

BIBLIOGRAPHY

Denhardt, R. M. (1948) The Horse of the Americas. Norman : University of Oklahoma Press.

Forester, F. (1857) The Horse of America. New York : Stringer and Townsend.

Law, R. (1980) The Horse in West African History. Toronto : Oxford University Press.

MacEwan, G. (1964) Hoofprints and Hitchingposts. Saskatoon : Modern Press.

Pocock, R. (1917) Horses. London : John Murray, Albemarle Street.

Ridgeway, W. (1972) The Origin and Influence of the Thoroughbred Horse. New York : Benjamin Blom, Inc.

Vernon, A. (1939) The History and Romance of the Horse. Boston : Waverly House.

Walsh, J. H. (1869) The Horse in the Stable and Field. London : George Routledge and Sons.