Tracing the Evolution of the Modern Horse
The horse, as we know it today, evolved from a considerably different form over a period of 55 million years. The earliest recorded ancestor of the horse is the Eohippus, which lived during the Eocene period.[1] From there, it evolved over millions of years through various forms and branches of the evolutionary line to become the domestic horse of today. Its evolution mainly consisted of changes in size, brain complexity, shape, length of the foreleg, and most significantly, a dental structure that changed to suit grazing on grass instead of browsing on high-growing plants.[1]