The Huayangosaurus dinosaur is the smallest species of prehistoric animals in the category of stegos. It had an estimated length of 4 m and a weight of 1.4 tons.
Its fossil remains, dating back to the Middle Jurassic era of Mesozoic era, 160 million years ago, were discovered in China. On their basis, paleontologist Dong Zhiming made a description of this species in 1982 and called it Huayangosaurus taibaii.
Compared to the body size, the skull was small narrow and flattened, the snout ending with a parrot-like beak, and the strong jaws were previously provided on the lateral sides with many teeth of different sizes and shapes, some larger in shape of a leaf, smaller, pointed and thin.
The dinosaur’s massive body was protected on the dorsal side by two rows of large triangular bone plaques that protruded from the head to the middle of the tail.
They were tightly tucked in the thick skin covering the animal’s body, they were different in size, the largest ones were positioned in the middle of the back, and the smallest in the neck and tail area. The researchers came to the conclusion that the plaques developed from the bony thorns – their posterior part was lengthened and changed the timing of the thimble over time.
The head was also protected by tiny, tiny bone and resistant scaffolds, and the tail end was provided with two pairs of sharp, very tough spines that resembled some bull horns. On the lateral sides of the shoulders there appeared a sharp, long-lasting spin with a protective flank.
The anterior limbs were about the same length as the posterior limbs, they were massive, finished with strong paws and fingered claw fingers. The dinosaur’s walk was quadruped, relatively slow and heavy.
The plates on the back of the Huayangosaurus also had a thermoregulatory role, they were covered with skin-pierced blood vessels that facilitated heat exchange with the environment. Also, by changing the color the plates discouraged the predators, and within the group during the mating season they had the role of attracting the female by the male.
The Huayangosaurus dinosaur populated the wooded forests and savannahs of China’s Jurassic territory and fed like any herbivorous animal with the plants on the ground.