Let's popularize some knowledge first: Equus originated from the Cenozoic Early Tertiary 60 million years ago, and its original ancestor was a protohoofed animal, with a body length of about 1.5 meters, a long head and tail, short and bulky limbs, slow walking, and often active in forests or tropical plains, feeding on plants. Short stature, five toes on all limbs, well-developed middle toe. Shi Xinma, or ancestor horse, who lived in the early Eocene of Tertiary 58 million years ago, was about 40 cm tall. The forelimb is low and has four toes; The hind legs are high and have three toes. Simple teeth, suitable for tropical forest life. After entering the Miocene, the dry grassland replaced the wet shrub, and the function and structure of the horse changed obviously: the physique increased, the limbs became longer and became single toe; Teeth become hard and complicated. After the gradual evolution of Singapore-Malaysia, China-Singapore-Malaysia and Shanghai-Singapore-Malaysia, it was not until the Quaternary Pleistocene that a single-hoofed, tall Malaysia appeared. Horses are widely distributed all over the world and originated in the grasslands of Central Asia. They were domesticated by humans more than 4000 years ago, and were brought to America and Australia by colonists after15th century. Asia has the widest distribution.