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Over the years, there's been a lot of speculation about various dinosaurs. As fossils have been studied, new theories have come to light – one being that certain dinosaurs, like the stegosaurus, had two brains. But does stegosaurus have two brains?
The stegosaurus did not have two brains, according to experts. The myth that stegosaurus had two brains began when a few paleontologists observed a cavity at the base of the spine and came up with a theory that it must have held a second brain. However, this cavity may have stored glycogen.
In this article, I’ll explain why people believed stegosauruses had two brains, animals that do have multiple brains, and some facts about the stegosaurus. I’ll also explore some other interesting ideas about dinos. Keep reading to learn more.
The myth of the stegosaurus having two brains began when a 19th-century paleontologist discovered a separate canal in the lower spine of a stegosaurus fossil. No one was quite sure why the canal was there.
At this time, scientists first asked, “Does the stegosaurus have two brains?”
After careful examination, it was inaccurately determined that the canal was large enough to hold a brain, so it must have held a second brain. Of course, there wasn't any proof of this. Nonetheless, the theory held, and it was assumed this was the case for many years.
One of the biggest reasons scientists assumed this was true is because the stegosaurus's brain was relatively small compared to the rest of its body. For many years, scientists couldn’t understand how such a tiny brain could operate the dinosaur’s body.
However, when they found the second brain-sized cavity, it all made perfect sense. They believed that the stegosaurus didn't only have a pea-sized brain. They had a whole second system.
Only in recent years, people came to the realization that the stegosaurus didn’t have two brains. This realization was based on a new theory that suggested the cavity was more likely used to store glycogen – a common substance found in the bodies of birds.
However, this is also only a theory and is still in the discovery stages. Expert Matt Wedel noted that even if the stegosaurus's cavity were filled with glycogen, they wouldn't know for what purpose. He said, "Since we don't even know what it does in birds, we're straight out of luck when it comes to figuring out what it did in sauropods."
Paleontologists have high hopes that soon they'll understand what glycogen does in birds and, more importantly, what function it performs for various sauropods, including the stegosaurus.
The idea that some animals have two brains has been around for a long time, even longer than the theory that the stegosaurus had two brains.
No animal that we know of has two whole brains. However, many animals have additional hemispheres, called ganglia, that allow additional functioning separate from the primary brain. The ganglia all act independently, and so sometimes certain animals are thought of as having “multiple brains.”
Humans only have one operating system – a single brain. As such, it can be challenging to comprehend that some animals have multiple operating systems that think independently of one another. While strange, this is actually a significant benefit to these animals.
Let’s talk about some of the animals that have multiple ganglia.
The octopus is one of the most intelligent creatures on the planet. They fearlessly navigate the oceans, swimming in between even the tightest crevices.
The primary brain of the octopus is located in its head, but this animal has eight other brains in each of its arms. According to AP News, the ganglia each operate separately, yet together toward the same goal. This gives the octopus tons of extra sensation that most animals don't have, which may be one reason they are so intelligent.
Despite being long despised, cockroaches are another animal (insect) with two brains. One of their brains is located in their skull, while the additional ganglia are in their abdomen.
Like the octopus, the cockroach has additional sensitivity because of this. This shouldn't be a shock if you've seen how quickly a cockroach responds when you come near it. If only humans could move this quickly.
Surprisingly, grasshoppers also have multiple brains. In addition to their primary brain located in their skull, their entire system is coated in various ganglia. This makes for insanely fast responses and an awareness that beats a lot of the competition.
A grasshopper's ganglia are separated the same way their bodies are. Some are in their head, some are in the abdomen, and others are in their thorax. This means that the grasshopper is constantly looking for trouble. However, they stay safer than most creatures.
There are several other animals that have excess ganglia. In most, the ganglia function roughly the same way. All of them have increased awareness and extra-sensory perceptionsdue to the ganglia.
Discovering what a creature looked and behaved like through fossils alone is challenging. Still, there are quite a few things that paleontologists know about the stegosaurus for sure – even if the two-brains theory wasn't correct.
Based on fossil evidence, paleontologists have determined that the stegosaurus was a plant-eating dinosaur that lived during the late Jurassic period – somewhere around 150 million years ago.
It would have eaten various plants such as ferns, grasses, trees, and flowers. Because the stegosaurus had a beak-like mouth, it likely didn't chew its food well. Instead, it probably looked for large and soft leaves that could be easily swallowed.
Most plant-eating dinosaurs had multiple herds that roamed various areas – stegosaurus included. Most stegosaurus fossils have been found spread across North America, so it’s assumed that this is where they primarily lived. The bones range from the lower United States to Canada.
Stegosaurus fossils have also been found throughout Western Europe, Southern India, and Africa.
The stegosaurus is one of the largest dinosaurs to have existed. Some remnants have been discovered that indicate the stegosaurus was up to thirty feet (nine meters) long. This is almost as large as many T-Rexes. This is why paleontologists were shocked when they began to study the dinosaur's brain.
As we discussed, the stegosaurus had a small brain. This dinosaur's brain was smaller than most other dinos, and considering the size of its body, this was quite an accomplishment. Some paleontologists even assumed that the stegosaurus couldn't do much more than walk and eat due to the size of their brains.
However, there’s little evidence for this. The nervous system of the stegosaurus would allow for extended movements, even with the size of the brain.
The stegosaurus is well known for its massive armor running along its spine. These triangular plates were made of bone material and ran from the top of the dinosaur’s head down to its tail.
No one knows for sure why the stegosaurus had the plates along its back, but the current theory is that it helped regulate the dinosaur's body temperature. This is indicated by the blood vessels that have been found inside them.
Another theory is that the plates were used primarily as a defense mechanism. Most plant-eating dinosaurs were seen as prey. While many used camouflage to blend in with the surrounding area, some, like the stegosaurus, had built-in protection.
The stegosaurus had a heavily arched back – primarily due to the different sizes of its limbs. The back limbs were significantly larger than the front, which forced the dinosaur into a curved position.
Additionally, the head of the stegosaurus was tiny in comparison to the rest of its body. This is also why it had such a small brain. The head sat at the end of a short neck. As a result, the dinosaur didn’t have long reach and ate primarily ground plants.
Stegosauruses weren’t solitary animals. Not only did they travel with herds of other stegosauruses, but they were also regularly surrounded by a few other types of dinos.
Stegosaurus likely traveled with and was regularly surrounded by dinosaurs such as the following:
Read about more dinosaurs in these articles:
This Is How Powerful an Ankylosaurus Is
Which Is Bigger: Apatosaurus or the Brachiosaurus
Spinosaurus vs. Mosasaurus: Which Is Bigger?
Giganotosaurus vs. Indominus Rex: Which Is Bigger? (We Find Out)
Since I’ve discussed the theory that the stegosaurus had two brains, I want to address another theory – did dinosaurs have two hearts?
There is little evidence that proves dinosaurs had two hearts. However, some dinosaurs may have had pseudo-hearts that helped pump blood throughout their massive bodies. Also, according to experts, one dinosaur, the barosaurus, may have had multiple hearts.
The idea that dinosaurs had two hearts came from the question of how one heart could support pushing blood through such a large body. It’s a valid question, as dinosaurs were gigantic. In addition, most dinosaurs didn’t have a calm and peaceful existence. Like most animals, they were either predators or prey, which required lots of running in either case.
To answer this question, paleontologists began to form some theories. One of these theories suggests that larger dinosaurs may have had additional pseudo-hearts that assisted in pumping blood through their bodies. These pseudo-hearts weren’t actual hearts but clusters of blood vessels that pushed the blood further throughout their veins.
For dinos with extra long necks, the blood flow would have been increased with movement. Their neck movement would inevitably shift the blood around and assist in moving it throughout the body, even without multiple hearts.
While there’s no hard evidence that suggests that dinosaurs had two hearts, it’s been suggested that one particular dinosaur may have had far more than two hearts. The theory states that the barosaurus may have had eight different hearts!
The barosaurus lived about 200 million years ago. It was similar to the brachiosaur, with a large body and long neck. It’s estimated that this giant was about 45 feet tall.
Because of its long neck, some scientists have suggested that the barosaurus had multiple hearts – up to eight located throughout its body.
The primary heart would have been located in the thorax. A secondary heart may have been at the base of the neck, and the others would have run up its neck to assist in blood flow. That’s a lot of hearts for one dinosaur.
If the barosaurus did have this many hearts, it certainly would have caused some problems in the long run. For example, the dinosaur may have been more prone to certain diseases. This could have led to an early death for many of these dinosaurs.
For more information about this dinosaur and the eight hearts theory, take a look at this article by the Washington Post.
The theory that stegosauruses had two brains was widely accepted for many years. However, as time has passed, paleontologists have disregarded this theory. Instead, they believe that the extra cavity in the stegosaurus likely held glycogen. However, they still aren't sure what role this played.
There are other animals that have multiple “brains.” These aren’t really brains but extra ganglia that operate independently of the primary brain. Some dinos may have also had multiple hearts, but there's no hard evidence. Still, it's an interesting theory.
Keep learning and growing. There’s always something new to discover.
