Modern Horse Evolution
If you were to think of a horse today, you would say they are big, strong mammals. 55 mya, horses did not look like this. With the mannerisms of a deer and the traits of a dog, the first known horse darted through forests in North America during the Eocene Period. As time went by, many horses evolved like the Orohippus, Epihippus, Mesohippus, Miohippus, Parahippus, Merychippus, Pliohippus, Dinohippus, and finally the Equus. In Greek, ‘hippus’ means horse.
Fossils of the first known horse were found in 1841, and were initially called Hyracotherium leporinum. In 1876, a full skeleton of it was found in North America by Othniel Marsh. It was then given the name Eohippus, which means “dawn horse”. Many believe it was the ancestor of modern day horses; however, some paleontologists think it was a cousin, not a direct ancestor. This horse was as big as a small dog, only about 12 inches tall and two feet long. Its characteristics are very different from the modern day horse.
The Eohippus had an arched back, short face, snout, and neck, and a long tail. It had four toes on its front feet and three on the back feet which all had pads on them, like a dog would. The teeth of this animal were very different. It had three incisors, one canine, four premolars, and three grinding molars on each side of the jaw. Although the features were different between the two, they had one similarity: Both were grazing herbivores. The area they lived in was covered in forests, encouraging the…