Stegosaurus armatus is a type of armored dinosaur from the Late Jurassic period.. Stegosaurus armatus is a type of armored dinosaur from the Late Jurassic period with distinctive tail spikes and plates along its spine. Colour printed illustration by Heinrich Harder from Tiere der Urwelt Animals of the Prehistoric World, 1916, Hamburg. Heinrich Harder (1858-1935) was a German landscape artist and book illustrator. These images come from a series of prehistoric creature cards published by the Reichardt Cocoa company in 1908. Natural historian Wilhelm Bolsche wrote the descriptive text.