Evolution of the Horse

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Evolution of the Horse The origin of the modern day horse dates back to almost 55 million years ago. The first known ancestor of the horse was called the Hyracotherium or Eohippus meaning “dawn horse”. This doggish like creature was only around 15 inches at the shoulder and had a short neck and short legs. It had four toes on each front foot and three on the hind feet. Unlike the modern day horse, it had a small brain with especially small frontal lobes. The Eohippus fed of fruit and soft foliage and roamed around the forest floor. Over five million years, three new species developed from the Eohippus: the Pachynolophus, Propalaeotherium, and the Orohippus. The Orohippus was much like the Eohippus. The only distinct differences were the Orohippus had more rigid teeth for tougher foliage, and its toes had become smaller and grew closer together. The earlier horse had no defense mechanism other than running away. Quick get aways were becoming more and more important to the species’ survival. After about thirty eight million years the equine bloodline was getting closer to perfection. The Merychippus were developed around 17 million years ago. These showed the most drastic yet change from their ancestor the Eohippus. The Merychippus had three toes on its front legs, but only stood on the middle on which was much larger than the other two. The two sides toes weren’t used for standing at all, as they didn’t touch the ground. The Merychippus was also tallest yet, reaching 40 inches. Rapid running over hard ground was the Merychippus’s specialty. Also, the eye sockets on their skulls had moved upwards allowing them to watch for predators while grazing. About 12 million years ago the first “one-toed” horse arose. This was called the Dinohippus which displayed the hoof-like feet we see today in horses. Finally, 50 million years after the first ancestor of the horse was

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