Stegosaurus
Stegosaurus is a characteristic stegosaurian of Late Jurassic with two rows of large dorsal dermal plates and two pairs of tail spikes. Because of long hind legs and the short fore legs about half the height of the hind legs, the pelvis was high, and it would have carried the head close to the ground. This attitude suggests that the main food of this dinosaur was short plants. However, due to the imbalance of the leg length, there would have been a limit to the speed of movement, and would have been a very slow dinosaur with a maximum speed of 7 km per hour (Fastovsky & Weishampel 2009).
Reliable restoration model
The dorsal dermal plates are arranged in two alternating rows, and the tail spines are attached to the side for easy attacks through swinging left and right.
Rhamphorhynchus
Rhamphorhynchus is the largest and the most widely-known Jurassic stegosaurian that have two rows of dormal dermal plates originated from skin ossification and two pairs of sharp tail spines, and is a herviborous ornithopod.
Stegosaurians are not a common fossil compared to other dinosaurs. Its traces are found in western North America, eastern Africa, western Europe, and eastern Asia, and it had flourished for about 70 million years from the Middle Jurassic (or Early Jurassic) to the Early Cretaceous, but fossils from the Cretaceous are extremely rare. In terms of evolution, they are a sister group of ankylosaurians with a common ancestor. Unlike ankylosaurians that evolved osteoderms into armor plates, stegosaurians developed long spikes, dermal plates, and longer hind legs.
Careful protection
This ankylosaurian found mainly in Late Cretaceous of Alberta, Canada, and Montana and Texas of United States of America is among the largest of the Family Nodosauridae, with a maximum length of 7 meters and 3.9 tons.
