U.S. #3077
1996 32¢ Eohippus
Prehistoric Animals
Issue Date: June 8, 1996
City: Toronto, Canada
Quantity: 27,730,000
Printed By: Ashton-Potter (USA) Ltd
Printing Method: Lithographed
Perforations: 11.1 x 11
Color: Multicolored
Eohippus was a small, plant-eating mammal that lived approximately 55 million years ago. Scientists have determined this animal was the horse’s first ancestor. Often referred to as the “dawn horse,” Eohippus stood about 15 inches high, and was about the size of a fox.
In fact, the dawn horse closely resembled a dog-like creature, as it lacked the straight back and long face of modern horses. The Eohippus had four toes on its front foot (one of these was non-functional), and three on its hind foot. Each toe ended in a separate hoof. The part of the foot which bore the animal’s weight was covered with a tough pad, much like a dog’s.
Scientists have determined from fossilized teeth that Eohippus was more of a browser than a grazer – which means it ate more like a rabbit than a horse. But, like today’s horse, the Eohippus depended on its speed to evade predators.
Nature began replacing Eohippus with a more horse-like animal, the Mesohippus or middle horse, about 35 million years ago. Twenty-six million years ago Merychippus (cud-chewing horse) emerged. It had three toes on each foot, but the strong, large-hoofed center toe bore all the animal’s weight. Animals resembling today’s horse appeared about 3 million years ago.