Hyracotherium or Eohippus; the dawn horse; extinct genus of perissodactyl ungulates that lived during the Tertiary to Eocene Epoch. Colour printed (chromolithograph) illustration by Heinrich Harder from 鈥楾iere der Urwelt' Animals of the Prehistoric World; 1916; Hamburg. Heinrich Harder (1858-1935) was a German landscape artist and book illustrator. From a series of prehistoric creature cards published by the Reichardt Cocoa company. Natural historian Wilhelm Bolsche wrote the descriptive text.