Log in Sign up
Back to Discover
🧬

Stegosaurus

life science Maturity 7-9

Stegosaurus was a big dinosaur.

Stegosaurus stenops Life Reconstruction.png
Stegosaurus stenops Life Reconstruction.png
It had plates on its back.
Stegosaurus plates.jpg
Stegosaurus plates.jpg
It had spikes on its tail.
Thagomizer (spike).jpg
Thagomizer (spike).jpg
These helped it stay safe.
Allosaurus attacks Stegosaurus.jpg
Allosaurus attacks Stegosaurus.jpg
It ate green plants for food.
Stegosaurus stenops skull cast - Natural History Museum of Utah - DSC07228.JPG
Stegosaurus stenops skull cast - Natural History Museum of Utah - DSC07228.JPG
It was very large.
Stegosaurus size comparison.svg
Stegosaurus size comparison.svg
Can you imagine seeing one?

44 words

Stegosaurus was a very large dinosaur.

Stegosaurus size comparison.svg
Stegosaurus size comparison.svg

It had big plates on its back. These plates may have helped it show off.

Stegosaurus plates.jpg
Stegosaurus plates.jpg

It also had sharp spikes on its tail. These spikes helped it fight off hunters.

Allosaurus attacks Stegosaurus.jpg
Allosaurus attacks Stegosaurus.jpg

This dinosaur had a small head. It used its head to eat low bushes.

Stegosaurus stenops skull cast - Natural History Museum of Utah - DSC07228.JPG
Stegosaurus stenops skull cast - Natural History Museum of Utah - DSC07228.JPG

Many people know this dinosaur today. It is very famous in books and films.

68 words

Stegosaurus was a large, four-legged dinosaur.

Stegosaurus size comparison.svg
Stegosaurus size comparison.svg

It lived a long time ago. It lived during the Late Jurassic period. This was between 155 and 145 million years ago.

Stegosaurus stenops Life Reconstruction.png
Stegosaurus stenops Life Reconstruction.png

Stegosaurus had many unique parts. It had big, upright plates on its back. These plates may have been for display. They might also help with thermoregulation. Thermoregulation is a way to control body heat.

Stegosaurus plates.jpg
Stegosaurus plates.jpg

It also had sharp spikes on its tail. Scientists think it used these for defense. These spikes could help fight off hunters like Allosaurus.

Allosaurus attacks Stegosaurus.jpg
Allosaurus attacks Stegosaurus.jpg

This dinosaur had a small head and a short neck. It likely ate low bushes and shrubs. It was a herbivore, which means it only ate plants.

Some species were very big. Stegosaurus ungulatus was one of the largest. It could weigh over 5,000 kilograms.

Stegosaurus size comparison.svg
Stegosaurus size comparison.svg

Many people know this dinosaur. It is in many books and films. Fossils have been found in the United States and Portugal.

158 words

Stegosaurus is one of the most famous dinosaurs in the world.

Stegosaurus size comparison.svg
Stegosaurus size comparison.svg
These large, four-legged animals lived during the Late Jurassic period. This was between 155 and 145 million years ago. They were herbivores, which means they only ate plants. Because they had small heads and short necks, they likely ate low bushes and shrubs.
Stegosaurus stenops skull cast - Natural History Museum of Utah - DSC07228.JPG
Stegosaurus stenops skull cast - Natural History Museum of Utah - DSC07228.JPG
They lived alongside other well-known dinosaurs like Apatosaurus and Diplodocus. Some predators, like Allosaurus, may have hunted them.
Allosaurus attacks Stegosaurus.jpg
Allosaurus attacks Stegosaurus.jpg

This dinosaur had a very unique way of looking. It had big, kite-shaped plates standing upright along its back.

Stegosaurus plates.jpg
Stegosaurus plates.jpg
Scientists think these plates were used for display or for thermoregulation. Thermoregulation is a way an animal manages its body heat. The dinosaur also had sharp spikes on its tail. These spikes were used for defense against predators.
Thagomizer (spike).jpg
Thagomizer (spike).jpg
Their bodies were heavily built with rounded backs. They had short front legs and much longer back legs. This meant they held their tails high in the air.

Finding these fossils was part of a famous time called the "Bone Wars." Othniel Charles Marsh first identified these remains in 1877. He worked at Dinosaur Ridge National Landmark. The first bones found were very broken and scattered. Because of this, it took many years to understand their true shape. Marsh even thought the plates laid flat like roof shingles at first. He named the animal "roofed lizard" because of this idea.

Stego.jpg
Stego.jpg

Many different types of Stegosaurus have been found.

Stegosaurus ungulatus.jpg
Stegosaurus ungulatus.jpg
Three species are widely recognized in the western United States. These are Stegosaurus stenops, S. ungulatus, and S. sulcatus. One species, S. ungulatus, was very large. It could weigh over 5,000 kilograms.
Stegosaurus size comparison.svg
Stegosaurus size comparison.svg
Fossils have been discovered in both the United States and Portugal. Over 80 individual animals have been found by researchers. Most of these fossils come from the Morrison Formation. This area is a famous place for finding dinosaur bones.

Today, you can see Stegosaurus in many places.

Stegosaurus ungulatus.jpg
Stegosaurus ungulatus.jpg
They appear in movies, books, and even on postal stamps. Many museums have large skeletons on display for people to see.
Stegosaurus stenops Life Reconstruction.png
Stegosaurus stenops Life Reconstruction.png
Because complete skeletons are rare, museums often make composite displays. This means they use bones from several different animals to make one display. The National Museum of Natural History has a famous mount of S. stenops. You can also find them at the American Museum of Natural History. These displays help us see how these amazing creatures once moved.

407 words

Stegosaurus is a famous genus of herbivorous dinosaurs from the Late Jurassic period.

Stegosaurus size comparison.svg
Stegosaurus size comparison.svg
These four-legged animals lived between 155 and 145 million years ago. They are easily recognized by the upright, kite-shaped plates along their backs. They also had sharp spikes on their tails. Scientists study these fossils to understand how these massive creatures lived.
Stegosaurus plates.jpg
Stegosaurus plates.jpg
Stegosaurus is one of the most iconic dinosaurs in history. It remains a subject of great interest for paleontologists and the public alike.

Stegosaurus had a very specific body shape. They were heavily built quadrupeds with rounded backs. Their front limbs were short, while their hind limbs were quite long. This body structure caused them to hold their tails high in the air.

Stegosaurus stenops Life Reconstruction.png
Stegosaurus stenops Life Reconstruction.png
They had small heads and short necks. Because of this, they likely fed on low-lying shrubs and bushes. Their brain-to-body mass ratio was relatively low. They lived alongside other dinosaurs like Apatosaurus, Diplodocus, and Camarasaurus.
Allosaurus attacks Stegosaurus.jpg
Allosaurus attacks Stegosaurus.jpg
Some predators, such as Allosaurus, may have preyed on them.

The function of their unique features is still studied. Scientists generally agree that the spiked tails were for defense. These spikes helped protect them from predators. The large plates on their backs served different purposes. They were likely used for display to other dinosaurs. They may also have helped with thermoregulation. Thermoregulation is the process of managing body heat.

Thagomizer (spike).jpg
Thagomizer (spike).jpg
This allowed the animal to control its temperature through the plates.

Researchers recognize three main species in the upper Morrison Formation. These are Stegosaurus stenops, Stegosaurus ungulatus, and Stegosaurus sulcatus.

Stegosaurus ungulatus.jpg
Stegosaurus ungulatus.jpg
Stegosaurus ungulatus was one of the largest stegosaurians known. Some specimens measured a great length and weighed over 5,000 kilograms. Stegosaurus sulcatus is notable for a large spike. Some scientists think this was a shoulder spike used to identify the species. Fossils have been found in the western United States and in Portugal. Over 80 individual animals have been discovered so far.

The discovery of Stegosaurus happened during the "Bone Wars." Othniel Charles Marsh first identified the remains in 1877. He worked at Dinosaur Ridge National Landmark. The first fossils were very fragmentary and scattered. Marsh originally thought the animal was an aquatic, turtle-like creature. He named it "roofed lizard" because he thought the plates overlapped like roof shingles. Later, he incorrectly assigned bones from other dinosaurs to this genus. It took many years to understand the true posture and plate arrangement.

Understanding the plate arrangement took a long time.

Stegosaurus ungulatus skeleton peabody museum 1910.png
Stegosaurus ungulatus skeleton peabody museum 1910.png
In 1901, Frederick Lucas suggested the plates were in paired rows. He even had an artist create a life restoration. However, scientists later debated if the plates were paired or staggered. Richard Swann Lull thought the plates shifted after the animal died. But Charles Gilmore argued that the alternating rows were natural. By 1924, the staggered pattern became the accepted standard. This changed how museums mounted the skeletons for the public.

Today, Stegosaurus is a star of natural history museums.

Stegosaurus ungulatus.png
Stegosaurus ungulatus.png
Because complete skeletons are rare, many museums use composite displays. A composite display uses bones from several different individuals. The National Museum of Natural History has a famous mount of S. stenops. The American Museum of Natural History also has a famous composite mount. These skeletons help us connect the biology of dinosaurs to the wider history of Earth. Stegosaurus continues to appear in films, books, and even on postal stamps.

562 words
🖼️ Images & Media (18)
File:Stego-marsh-1896-US geological survey.png
Stego-marsh-1896-US geological survey.png
File:Stegosaurus ungulatus skeleton peabody museum 1910.png
Stegosaurus ungulatus skeleton peabody...
File:Stego.jpg
Stego.jpg
File:Stegosaurus size comparison.svg
Stegosaurus size comparison.svg
File:Stegosaurus stenops skull cast - Natural History Museum of Utah - DSC07228.JPG
Stegosaurus stenops skull cast - Natural...
File:Stegosaurus ungulatus.jpg
Stegosaurus ungulatus.jpg
File:Stegosaurus stenops Life Reconstruction.png
Stegosaurus stenops Life Reconstruction.png
File:Stegosaurus ungulatus.png
Stegosaurus ungulatus.png
File:Stegosaurus dorsal plate - Museum of the Rockies - 2013-07-08.jpg
Stegosaurus dorsal plate - Museum of the...
File:HMNS Stegosaurus.jpg
HMNS Stegosaurus.jpg
File:Allosaurus attacks Stegosaurus.jpg
Allosaurus attacks Stegosaurus.jpg
File:Stegosaurus plates.jpg
Stegosaurus plates.jpg

+ 6 more

Up Next
🧬
Stegosauria
Life Science
More to explore

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.