Stegosaurus was a genus of herbivorous dinosaur that lived during the Late Jurassic in what is now Europe and North America.
The largest species of Stegosaurus could grow to around 10.03 meters in length and have a height of around 4.5 meters at the hips. It might have exceeded 5,300 kg.
Stegosaurus had two rows of plates on its back alternating, meaning that no two plates were of the same size and no two plates were lined up with each other. It also had four spikes, also called "thagomizers," on its tail.
The living creature
Despite its large size, the head of Stegosaurus was positioned fairly low, although, not as low as previously assumed, meaning that it was a low-level browser.
Evidence suggests a predator-prey relationship between Allosaurus and Stegosaurus. It's thagomizers would have been an effective defense mechanism, and Stegosaurus would have certainly been a difficult target. An Allosaurus specimen was found with a thagomizer puncture wound.
Stegosaurus is one of the most famous dinosaurs due to its iconic plates. The use of these is still being debated. One idea is that they were used for display between Stegosaurus individuals.
A cavity was found to exist in the spinal cord of Stegosaurus toward the hips. This has been interpreted as being a second brain, perhaps used to make up for the small "primary" brain. This idea was perpetuated throughout the 20th century, being cited, for example, in Ray Bradbury's short story A Sound of Thunder. The notion of Stegosaurus having a second brain is, politely put, extremely absurd, especially considering other forms of dinosaur including modern birds possess a similar cavity.
While material from Africa and Europe is occasionally assigned to dinosaurs known primarily from North America such as Ceratosaurus, these remains are typically quite scant, and their correct assignment is often disputed by paleontologists. However, at least one specimen of Stegosaurus is known from Portugal.