“Roofed Lizard” discovered in Colorado in 1876 by M. P. Felch & described by Othniel C. Marsh in 1877. Stegosaurus lived during the Late Jurassic Period about 154 to 150 million years ago. It was 12 meters (40 ft.) in length, 5.8 meters (19 ft.) in height at the top of the plates, & 7 tons in weight. The ones in the Jurassic Park novel are 20 ft. in length with 3 foot long spikes.
