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 …show more content…
The climate became cooler, drier, and more seasonal. Ice sheets were growing on Antarctica. Forests continued to recede, and grasslands or deserts replaced those areas. South America became linked to North America through Panama. Africa collided with Europe, creating the Mediterranean Sea. Sea levels also changed, exposing the land bridge between Alaska and Asia. Although horses died off in Europe, the exposure of the land bridge allowed them to cross back into Asia and spread. Pliohippus was believed to be the direct ancestor of present day horses. However, its skull had deep facial fossae (the modern day horse has none) and its teeth were very curved (the modern day horses were straight). This was one of the first horses that had only one toe. The side toes formed into splint bones on either side of the cannon bone and the pads have developed into the frog on the sole of the hoof. It was about 51 inches tall and had a strong, solid, body like the horses today.
Another one-toed horse was found called the Dinohippus. This evolved about 12 mya. Its forelimbs were strong with a single toe. Hind limbs were strong and powerful. Its body was strong and sturdy, and its neck was muscular and powerful. It was about 60 inches tall. The legs and feet were adapting this way so that it could stand for extended periods of time with minimal energy. It was the closest horse to the Equus, the modern day
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 …show more content…
The climate became cooler, drier, and more seasonal. Ice sheets were growing on Antarctica. Forests continued to recede, and grasslands or deserts replaced those areas. South America became linked to North America through Panama. Africa collided with Europe, creating the Mediterranean Sea. Sea levels also changed, exposing the land bridge between Alaska and Asia. Although horses died off in Europe, the exposure of the land bridge allowed them to cross back into Asia and spread. Pliohippus was believed to be the direct ancestor of present day horses. However, its skull had deep facial fossae (the modern day horse has none) and its teeth were very curved (the modern day horses were straight). This was one of the first horses that had only one toe. The side toes formed into splint bones on either side of the cannon bone and the pads have developed into the frog on the sole of the hoof. It was about 51 inches tall and had a strong, solid, body like the horses today.
Another one-toed horse was found called the Dinohippus. This evolved about 12 mya. Its forelimbs were strong with a single toe. Hind limbs were strong and powerful. Its body was strong and sturdy, and its neck was muscular and powerful. It was about 60 inches tall. The legs and feet were adapting this way so that it could stand for extended periods of time with minimal energy. It was the closest horse to the Equus, the modern day