The horse (Equus ferus caballus) is a hoofed (ungulate) mammal, a subspecies of one of seven extant species of the family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today. Humans began to domesticate horses around 4000 BCE, and their domestication is believed to have been widespread by 3000 BCE; by 2000 BCE the use of domesticated horses had spread throughout the Eurasian continent. Although most hor… (More on Equine)