Stegosaurus
A herbivorous dinosaur that had a maximum length of 9 meters and a height of 4 meters. The dinosaur weighed about 4 tons. The dinosaur's brain weighed only 70 grams.
Stegosaurus swallowed small stones, which helped the dinosaurs' digestive system by grinding the food. What Stegosaurus needed dorsal plates for, scientists have not yet figured out. It is assumed that they served as a defense against predators, although they were not so strong for protection. Perhaps they served the function of thermoregulation of the dinosaur.