The eohippus, an extinct group of mammals, is considered the ancient ancestor of which present-day animal?
And the answer: horse.
Also known as the dawn horse, the eohippus belonged to the genus Hyracotherium and flourished in North America and Europe between 55 million and 45 million years ago. This animal was small — almost dog-sized — and is believed to also be ancestral to rhinoceros, tapirs, and the also-extinct Beast of Baluchistan.
The Hyracotherium genus is believed to the that which predates all odd-toed, hoofed mammals. From this species descended many “horse-like” animals that make up the family tree (or in this case, the family bush) of the horse family and its cousins. The head of the Hyracotherium was short, and its eyes were in the middle of the skull. As a prey animal, its back was rounded and it may have had a striped coat for camouflage.
Fossils of Hyracotherium are found at many Eocene localities in the western US and Europe. At the time of their discovery, these fossils were believed to be that of a monkey. This is due to the fact that the teeth of these horses are quite primitive, like those of monkeys and other primates (such as humans). 19th century British anatomist, Richard Owen, initially thought that this animal proved that primates once lived in England. Ultimately, he corrected his mistake after studying more specimens.
Learn more about the history and significance of the Hyracotherium here.