Stegosaurus:  The double row of bony plates on its back and the cluster of dangerous spikes on its tail made Stegosaurus one of the most distinctive and well-armed creatures that has ever walked the earth.

Genus Name: Stegosaurus ("roofed lizard")
Type Species: * S. armatus (Marsh, 1877)
Length: 25-40 feet (8-12 meters)
Weight: 4-7 tons
Time: 160-145 million years ago (Late Jurassic)
Place: Colorado, Utah, Wyoming
Diet: plant-eater (herbivore)