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July 30, 2026Short & citedBlog
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Field Notes • Dinosaurs

Stegosaurus

Stegosaurus is a genus of armored, herbivorous dinosaur from the Late Jurassic period.

Updated July 30, 20261 min readCited sources

Stegosaurus is a genus of armored, herbivorous dinosaur from the Late Jurassic period. It is best known for the large bony plates along its back and the spikes on its tail.

What it is

Stegosaurus was a large, quadrupedal dinosaur with two rows of broad plates running along its back and a spiked tail. Its distinctive silhouette makes it one of the most recognizable prehistoric animals. The name means "roof lizard," referring to the plates.

How it lived

As an herbivore, Stegosaurus likely fed on low-growing plants like ferns and cycads. Its tail spikes are widely interpreted as a defensive weapon against predators. Despite its size, its brain was very small relative to its body.

Where it was found

Stegosaurus fossils are mainly known from the western United States, especially in the Morrison Formation of Colorado, Utah, and Wyoming. It lived about 152–145 million years ago during the Late Jurassic. It is the best-known member of the stegosaur family.

In short

  • One of the most recognizable dinosaurs due to back plates and tail spikes.
  • Quadrupedal herbivore from the Late Jurassic.
  • Fossils found mainly in western North America.
  • Tail spikes likely used for defense.
Canadian angle

Stegosaurus is a major dinosaur for Canadian readers because it is a classic museum and textbook example of Jurassic life and armored dinosaur anatomy. Canadian museums and science education materials often use Stegosaurus to teach about dinosaur classification and adaptation.

Quick questions

What does Stegosaurus mean?
It means "roof lizard" or "roofed lizard," referring to its back plates.
What did Stegosaurus eat?
Stegosaurus was an herbivore and likely ate low-growing plants such as ferns and cycads.
How did Stegosaurus defend itself?
Its tail spikes were probably used for defense against predators.

Sources

  1. Natural History Museumhttps://www.nhm.ac.uk/discover/dino-directory/stegosaurus.html
    Supports: Name meaning, diet, time period, length, and general description.
  2. Encyclopaedia Britannicahttps://www.britannica.com/animal/Stegosaurus
    Supports: Genus status, Late Jurassic age, size range, and distinguishing plates/spikes.
  3. National Geographic Kidshttps://kids.nationalgeographic.com/animals/prehistoric/facts/stegosaurus
    Supports: Back plates, tail defense, approximate age, fossil regions, and small brain.
  4. Live Sciencehttps://www.livescience.com/24184-stegosaurus-facts.html
    Supports: Late Jurassic range, western North American distribution, plates, size, and herbivory.
  5. National Park Servicehttps://www.nps.gov/places/stegosaurus-ungulates.htm
    Supports: Plant-eating dinosaur, Late Jurassic North American occurrence, and name meaning.