The fossil record of horses shows that over millions of years, horses have become larger, developed hooves in place of toes, and have adapted to eat grass instead of leaves.
The fossil record of horses was found in sedimentary strata since the beginning of tertiary period in a life span known as Eocene. That is about 50 million years ago.
According to evolution theory, it is very possible to follow horse evolution through millions of years: how the horse became larger and stronger, lost most of its toes, and how the structure of its tooth changed when its moved from eating plant, trees and shrubs to feeding on high dry grass. The horse evolution is believed to been fueled by drying and cooling climate.
The first set of horses lived in humid forest; it is a forest that is full of plant rich in foliage. Their toes, with three at the rear and four at the front spread out at different angle, and this really helped them from drowning into marshy grounds. Plants rich in foliage disappears as climate became drier and new huge grass fields formed. As a result of dried land, the grazers become better runner and were able to escape predators.
All the horses are categorized as the same family (Equidae) because they all resemble each other and due to the striking similarities, it can be hard to recognize any differences through the study of fossils skeleton alone.
LEARN MORE:
KEYWORDS:
