Meet a heavily-armored, 7-ton male Stegosaurus, an interesting enigma. He too is a herbivore, but very dangerous.
— Allen, about Stegosaurus
in Time of the Titans

Stegosaurus (steg-oh-saw-us; meaning "Roof Lizard"), is a genus of armored stegosaurian dinosaur from the Late Jurassic period. It is characterized for its distinctive spinal plates and thagomizer. Stegosaurus was the largest of the Stegosaur family of dinosaurs, 9–11 meters long, 3–5 meters tall and weighing 7 tons.

It is one of the most easily recognizable/identifiable dinosaurs, due to the distinctive double row of tall, kite-shaped plates rising vertically along its arched back and the two pairs of long spikes extending horizontally near the end of its tail. However, it was also one of the least intelligent dinosaurs, having a brain the size of five walnuts. 



Stegosaurus lived during the Late Jurassic Period from 156–145 million years ago. It shared the environment with the massive sauropods, and little bipedal dinosaurs, and the massive Allosaurus. Stegosaurus was first discovered in Colorado by Othniel Charles Marsh in 1877.


ImagesBA BrachiosaurusWithStegosaurus

Stegosaurus was a heavily-armored herbivorous dinosaur that stood 14 feet tall (17 feet at the tallest plate), measured about 36 feet (11 m) in length, and weighed 7 tons (14,000 lbs.) making it the largest member of its family. Stegosaurus was primarily green and yellow with dark green splodges. The spots were outlined with white. The plates were translucent and the rim of the plates was blueish-green.

Stegosaurus is famous for their distinctive row of 17 large spinal bony plates on their backs, which were primarily there for display rather than defense, which would be an odd place for armor. The plates along were embedded in the skin of the animal, not attached to its skeleton, which is why in most fossil finds the plates are separated from the body. The function of the plates has been much debated. Initially thought of as some form of armor, researchers have also proposed that they may have helped to control body temperature. Wind tunnel tests have suggested that the plates are well shaped to gather and dissipate heat.

But it was the four, lethal, meter long spikes on the end of their tails that made Stegosaurus such a lethal dinosaur. Its tail spikes were known for being, without question, one of the most dangerous weapons ever evolved by a plant eating animal, let alone, a dinosaur. Such a weapon appears as necessary, considering Stegosaurus coexisted with large predatory theropod dinosaurs, such as the fearsome Allosaurus. Stegosaurus could weal those spikes with devastating effect, despite having a very small and remarkably tiny brain, at only 80 grams, for their body size, which is what they were also known for, despite their hefty size, and was apparently sufficient for their needs.


Stegosaurus generally lived in pairs, but they have been known to have travel in small herds as well. They also were often solitary creatures, as they sometimes ate, drank, and even traveled by themselves. Stegosaurus was not the brightest of beings. Due to its low intelligence, it was unable to probably determine what was dangerous and what was harmless. Stegosaurus would often mistake small dinosaurs, even harmless ones like Dryosaurus, as a threat and those unfortunate animals would often be slaughtered.

Although Stegosaurus was a plant-eating dinosaur, they were nevertheless awfully dangerous creatures. Whenever they faced predators, Stegosaurus could flush blood into their plates and that created a colorful but terrifying display, which was capable of confusing and intimidating even a fully grown Allosaurus. But when attacked, Stegosaurus wielded the spikes on its tale with devastating effect. Stegosaurus was a species of dinosaur that stood and fought with lethal spines.