Stegosaurus

The Secret to Its Strength: Its Heavily Armored Body

The secret to Stegosaurus’s strength lies in its heavily armored body.
The four sharp, meter-long spikes on the end of its tail were its weapons for fighting enemies.
In fact, a fossil of an Allosaurus with a wound that appears to have been caused by a spike has been found, confirming that the spikes were indeed used as weapons.

Four sharp spikes on the end of its tail

Additionally, its throat, which at first glance appears defenseless, was covered in over 100 small, pebble-like ossicles, providing a very flexible yet robust armor.
Small bones were also embedded under the skin around its hips, and this heavy armor is believed to have played a crucial role in protecting it from ferocious carnivorous dinosaurs.

The Mysterious Back Plates: A Weapon, or Something Else?

The most distinctive feature of Stegosaurus, its back plates, formed a mysterious shape made of 16 interconnected bony plates.
When fossils were first discovered in the 1870s, the plates were thought to be a defensive weapon that covered its back.
However, this theory was later questioned because the plates were very thin and lacked durability.

A hundred years after the fossil’s discovery, traces of blood vessels were found on the surface of the plates, leading to the theory that they were an organ for thermoregulation, absorbing solar heat and dissipating excess heat.

A theory was proposed that the plates were a thermoregulation organ for absorbing and dissipating solar heat

However, since the number of blood vessels in the plates was limited, their effect was likely minor.
Currently, many paleontologists speculate that the plates had flashy colors and patterns and were used as a display for social signaling or for attracting mates.
That being said, the edges of the plates were as sharp as blades, so their potential use as a weapon cannot be ruled out.
Their function may not have been just one thing.

Small Head and Body Characteristics

Stegosaurus is characterized by its unusually small head relative to its gigantic body.
Studies of its skull have revealed that its brain capacity was only about 28 grams, roughly the size of a walnut.
This makes it one of the smallest-brained dinosaurs ever discovered.

An unusually small head for its huge body

A theory once suggested that it had a “second brain” in its tail, but this has since been disproven.

Its body mass was about 2.5 to 3.5 tons, similar in weight to a modern white rhinoceros.
It had short forelimbs and a distinctive arched posture, with its hips positioned higher than its shoulders.

It lived in an arched posture, with its hips higher than its short forelimbs.

Due to this body structure, it was completely unable to run away from enemies.

A Unique Eating Method

Stegosaurus was a herbivore with a small head, a long snout, and small teeth located only at the back of its mouth.
When eating, it used its sharp beak to pluck low-lying plants from the ground.

It used its beak to pluck plants from the ground.

It would rub its upper and lower teeth together to chew and finely chop the plants.
It is also believed that it had cheek pouches to temporarily hold plucked plants before chewing them.

Summary

Despite the visual impact of its appearance, much about Stegosaurus’s ecology remains a mystery.
However, its heavily armored body is the ultimate proof that it thrived throughout the Late Jurassic period and was widely successful around the world.