The name of the Stegosaurus comes from the Greek and means lizard with roof or roof, this because it had plates and thorns on the tail and back that make them a very special and recognized dinosaur by many. The Stegosaurus lived in North America almost at the end of the Jurassic period, 150 million years ago, in the Kimeridian and Titonian periods. Three different species of Stegosaurus are known and at least 80 individuals have been found, sharing the land with Diplodocus, Camarasaurus and Apatosaurus.

They were very heavy quadrupeds, they could reach 16 meters long, 4 meters high and weigh about 4 tons. Although it was very big, it was not as big as the giant sauropods that lived with it. The way he stood was very particular, because his back formed a large arch and his front legs were very short, his tail was horizontal and rigid in the air, he did not drag it and his head was a little bent down and very close to the ground. His head was very small, for his size, more or less like a dog’s, only his head ended up with a beak much like a parrot’s and he had small teeth that were not very good at chewing. Their legs ended in hooves, with three fingers on the hind legs and five on the front, some of their fingers were shaped like helmets.

There is much debate about the size of his brain, as it was considerably small for its size, weighing about 80 grams, more or less like a large nut. At first many thought dinosaurs were not very intelligent. Today scientists know that brain size has nothing to do with intelligence and that most dinosaurs could handle themselves very well with a small but very effective brain.

The Stegosaurus was discovered and described in the War of the Bones, its name was suggested in 1877 by Othniel Charles Marsh, who believed that the plates of the loin completely covered the animal such as a roof and for that reason he named it so.

The first remains of Stegosaurus were discovered in Morrison, Colorado, in the United States. The first to be discovered was a Stegosaurus armatus, which quickly became the stereotype of Stegosaurus that we now know. This type of Stegosaurus does not have as many spikes in its tail and its plates are a little irregular, yet it is very close to the reality of these dinosaurs.

The main clue we have about his feeding is that his head was low, that is to say very close to the ground, this suggests that he could have been ramoneador, this means that he fed on leaves, plants and branches that grew near the ground, hence his beak was very helpful to pull out these branches or grasses. The Stegosaurus, having a beak, had no front teeth, only at the back to chew the branches. These teeth were very small and triangular in shape, the faces of their teeth were flat, and in the specimens that have been found are worn, indicating that they chewed their food a lot. Because of the position of his jaw, it is believed that he had wide cheeks in which he kept his food while chewing it, since due to his type of teeth this was a very long process.

The Stegosaurus, in addition to plants and ferns, also had the ability to eat fruits such as pineapples or anything else they could find near the ground. It is believed that like other dinosaurs, they could have used gastrophy for their digestion, that is to say, they swallowed small stones that remained in their stomachs and helped them to crush food that they could not chew effectively, this same mechanism is used by some birds and crocodiles nowadays.

Without a doubt, its plates and thorns are what make Stegosaurus special. It had approximately 17 plates, which were separated from each other, these plates were osteodermal, ie bone plates that are found in the skin of animals and are not necessarily directly connected to the bones, crocodiles and other reptiles have in the skin some things similar to what we call scales. In the case of stegosaurus, they were not connected to the bone, but were part of the skin. Early theories suggest that these plates, which measured up to 60 centimeters, were used as a defense mechanism. The plates and spines were distributed parallel on his back, although it is also believed that he may have had some in the body formed an armor.

Other theories suggest that the plates were too thin, so they could not be much of a defense, but they could be used to impress their predators, because when the plates were upright, the Stegoaurus looked much bigger than it was. These plaques were very vascularized, that is to say that there were many veins and arteries that reached them, so a lot of blood flowed through them, so I told us that if they were injured in this part they could lose a lot of blood and die. Although this vascularization also suggests that the plaques may have changed color at the will of the Stegosaurus, showing really impressive and dangerous. The colors could also have been used for courtship.

The latter theory tells us that the plates could be used for thermoregulation, i.e. to maintain his body temperature. They needed to correct their temperature, because they ate huge amounts of plants and because of their teeth could not process it well, the food spent a lot of time in their intestines, which caused a lot of heat, so the plaques helped keep them cool while digesting huge amounts of food.

Where else can you find him?

In the mid 70’s the dinosaurs began to become much more famous and known, part of this was for the book The Lost World where the Stegosaurus appears, written by Arthur Conan Doyle, the same one who wrote the books of the famous Sherlock Holmes. You can also find it in the 1933 film King Kong, Fantasy, Journey to the Beginning of Time, Planet Dinosaurs and in Search of the Enchanted Valley. Of course he appears in Jurassic Park II and the documentaries The Animal World, Jurassic Fight Club and Walking with Diosaurs.