The family of dinosaurs known as stegosaurs are well known for the two rows of bony plates along their backs. Researchers once thought these plates helped protect the animal from attack. But the plates were often very thin and contained numerous blood vessels, so they would have been too weak to serve as defensive features. Instead, the plates, which were covered in skin, may have been brightly colored; stegosaurs might have used the plates in dramatic courtship displays. Other kinds of stegosaurs had rows of spikes on their backs instead of plates.
The numerous grooves visible on some Stegosaurus plates provide evidence that blood vessels once crisscrossed the surface of the bone. Any wound to the plate would have bled considerably, making it unlikely that such plates were used to protect the animals. Instead, stegosaurs might have used plates in mating rituals or to help regulate body temperature.
Fast Facts: Stegosaurus
- Pronunciation: "steg-oh-SORE-us"
- LENGTH: 9 meters (30 feet)
- HEIGHT: 4 meters (12 feet)
- WEIGHT: up to 2 tons
- Food: plants
- When it lived: 150 million years ago
- Fun fact: Stegosaurus had sharp spikes on its tail, which may have been used as weapons against attackers.