Hyracotherium: The ancestor of the modern horse, first appeared in the early Eocene epoch in the forests of North America. Also known as Eohippus, the "Dawn Horse", it was the size of a small dog. Unlike horses today, this primitive horse had several toes on each foot.

Name: Hyracotherium
Length: 2 feet
Weight: 15 pounds
Time: about 50 million years ago (early Eocene)
Place: North America
Diet: plant-eater (herbivore)