Diplodocus is a genus of extinct diplodocid sauropod dinosaur of the Late Jurassic period. Colour printed 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.