Used with
permission of Maiken Naylor, University at Buffalo, Buffalo, NY, USA,
http://ublib.buffalo.edu/libraries/units/sel/exhibits/stamps
Eohippus, a primitive four-toed horse of Europe and North America, is the oldest fossil record of the evolution of the horse family. This dog-sized animal dates back to the lower Eocene period, or 50 million years ago. The German stamp shows a German fossil; the U.S. stamp, an artist's conception of the animal that roamed this country. The companion stamp to the little horse shows a fossil bat.