Horse Trivia

Since Hyracotherium (Eohippus) has first appeared on the earth, the horses have developed vari-ous parts of their body.

The most evolved parts of their body are the limb.

Although Hyracotherium (Eohippus) was an inhabitant in the forest, the ancestor of Equidae has to adapt themselves into the new environment such as fields due to the global climate change and other factors.

It became necessary to run faster to escape from their predator as there were considerably fewer places to hide in the grassland.

In order to do so, the number of their toes were reduced and developed into the hooves. The foot was supported by flexible ligaments.

Hyracotherium (Eohippus), known as the ancestor of Equidae, had four-fingered toes on each fore-limb and three-fingered toes on each hind limb.

Mesohippus lived in 32 to 24 million years ago from the end of Eocene to the Oligocene. Forelimb also has become a three-fingered ( degeneration fifth finger of the forelimb ) , both forelimb and hind limb became the three fingers.

The middle toe was developed, although the other two were still exist on the side, they were very small and barely touched the ground. Therefore, it thought that Mesohippus stood predominantly on the middle toe.

Mesohippus had a larger body with longer limb than its predecessor Hyracotherium (Eohippus), it stood about 60cm tall.

Gradually it improved its body features suitable for running faster.

The face of Mesohippus became longer and larger than earlier ones and also teeth were evolved to suit to grind the grasses.

Merychippus lived in the middle of Miocene to Pliocene.

Merychippus was taller than Mesohippus, it stood approximately 100 cm.

Due to the major global climate change, the grassland area was dramatically increased therefore Equidae needed to be evolved themselves to fit into the new environment. Merychippus is consid-ered as the first horse known to have grazed.

As an evidence, their molars were beginning to form a series of tall crests with higher crowns.

Grass contains fine particles of glass therefore teeth will be scuffed by this fine particles. To prevent this, the Merychippus needed to have tall molars.

It had three toes on each foot but the middle toe developed into a hoof, other two were too small to not reach to the ground. It stood solely on the middle toe.

Pliohippus arose around 5 million years ago.

Two toes on both sides of the middle toe were barely visible and finally it stood on one hoof (which evolved from the middle toe).

Pliohippus became the first horse appeared in the history of the horse evolution with a single toe (hoof).

With its long and slim limb, Pliohippus were able to run faster than other creatures.

Pliohippus stood approximately 100 cm, other features such as teeth were similar to the modern horse.

Pliohippus has been believed to be the direct ancestor of the present-day horse, because of its many anatomical similarities.

Equidae have been evolved for tremendously long years since Hyracotherium (Eohippus) has first appeared on the planet.

Finally, the ancestor of the modern horse called Equus was appeared 1 million years ago.

Equus, originally from the Middle east and widely spread through the world, is considered as the ancestor of Equidae, including horses, zebras and donkeys.

Equus had all key features of the modern horses; stood on the single toe, reached to 120cm tall, had suitable tooth and a neck for herbivory, separately positioned eyes to have a wide range of vision.

Equus evolved themselves further to adapt various environment depending on where they lived, then have been bred by the human race to meet their needs.

This is the process of the evolution of horses.