Where have Stegosaurus fossils been found?
Stegosaurus is represented here by selected fossil records from western north america, especially morrison formation fossil localities. Fossil Atlas maps those records as modern discovery locations.
Fossil Atlas: Specimen ProfileStegosaurian dinosaurCatalog FA·STEG·1877
Plate 04 · Herbivore
StegosaurusFossil map and specimen profile
“The Plated Puzzle of the Morrison”
Binomial Stegosaurus stenops · STEG-oh-SORE-us
Late Jurassic - 155-145 Ma
Illustration- Classification
- Stegosaurian dinosaur
- Family
- Stegosauridae
- Genus / Species
- Stegosaurus stenops
- Diet
- Herbivore
- Range
- Western North America, especially Morrison Formation fossil localities.
Quick provenance answer
Where have Stegosaurus fossils been found?
Stegosaurus fossil records in Fossil Atlas are mapped as selected modern discovery locations, with 70 source-backed records currently shown. Western North America, especially Morrison Formation fossil localities. Key mapped formations in the current dataset include Morrison Fm, Morrison, Praia da Amoreira-Porto Novo. These pins are fossil record locations, not a complete ancient habitat map.
- Mapped records
- 70
- Modern range note
- Western North America, especially Morrison Formation fossil localities.
- Key formations
- Morrison Fm, Morrison, Praia da Amoreira-Porto Novo
- Map caveat
- Modern fossil locations, not ancient habitat.
Field account
Stegosaurus was a herbivorous thyreophoran dinosaur from the Late Jurassic of western North America. Fossil Atlas maps selected records dominated by Morrison Formation localities, with additional records from related source data. It is famous for the upright plates along its back and the four spikes at the end of its tail. The tail spikes were defensive weapons, while the plates have been interpreted as display structures, species-recognition signals, or possible thermoregulatory surfaces. Stegosaurus walked on four legs and used a toothless beak and small cheek teeth to crop low vegetation. The fossil map should be read as a set of modern discovery records, not a complete reconstruction of its Jurassic range.
Built to scale
Size against a person
Drawn true to scale on a metre ruler.
0 m2468101214161820222426
Stegosaurus, 9 m (30 ft)Adult human, 1.8 m≈ 5× longer than a person is tall
Field measurements
Measurements & capabilities
MeasuredEstimate
Length
measured9 m · 30 ft
Largest known specimens
Height
measured4.3 m (14 ft) including plates
Body mass
estimate3,600 kg · 8,000 lb
Typical adult
Top speed
estimate11 km/h · 7 mph
Modelled, debated
Brain : body (EQ)
estimate0.1
Encephalization quotient
How Stegosaurus lived
Stegosaurus was a slow-moving herbivore that cropped low vegetation with its toothless beak and processed it with small cheek teeth further back. It shared the Morrison landscape with large predators and enormous sauropods, occupying a distinct low-browsing niche. Its plates and tail spikes are the features most studied, and neither function is fully resolved.
The plates
Two alternating rows of upright bony plates along the back, embedded in skin rather than attached to the spine. Whether they were for display, species recognition, or temperature regulation is still debated.
The thagomizer
Four horizontal spikes at the tail tip. An Allosaurus vertebra with a healed wound matching the spike dimensions provides direct evidence that these were used in active defense.
Feeding
A beak at the front and small, weak cheek teeth suggest a soft-plant diet. Stegosaurus could not process the tough vegetation that large sauropods ate.
Build
Small head relative to body, short forelimbs, and a strongly arched back. Not a fast animal, but difficult to attack from behind due to the tail spikes.
Known from
Fossil evidence
01Plates
02Spikes
03Partial skeletons
04Quarry material
Key formations
Morrison FmMorrisonPraia da Amoreira-Porto NovoUpperCedar Mountain
Geologic timeline
When they lived
Position of this animal’s known range across 252 million years of the Mesozoic and beyond.
252 MaToday
155-145 million years ago
Field notes
01
Stegosaurus had a small brain relative to its body size, a point often exaggerated in older popular accounts.
02
The plates on its back may have been used for display, species recognition, or thermoregulation.
03
The four tail spikes, often called the thagomizer, could injure predators.
04
Stegosaurus lived in ecosystems that also included animals such as Allosaurus, Apatosaurus, and Diplodocus.
05
Most Fossil Atlas Stegosaurus records are tied to Morrison Formation localities.
06
The plates were embedded in the skin rather than directly fused to the backbone.
07
The name Stegosaurus means 'roofed lizard,' based on an early mistaken interpretation of its plates.
How we know Stegosaurus
Othniel Charles Marsh described Stegosaurus in 1877 from Morrison Formation material collected during the competitive fossil-hunting period known as the Bone Wars. Early reconstructions placed the plates flat along the back like roof tiles, which is where the name roofed lizard came from. Later work corrected that interpretation. A well-preserved specimen found in Wyoming in 1992, nicknamed Sophie, provided detailed plate and skeletal information that has since informed most reconstructions.
Shared the landscape
Lived alongside
Animals known from the same deposits and time as Stegosaurus.
Allosaurus
The main large predator of the Morrison Formation and the most likely source of the healed puncture wound found in an Allosaurus vertebra that matches Stegosaurus tail spikes.
Apatosaurus
A massive sauropod sharing the same floodplain ecosystems, occupying a very different feeding niche.
Camarasaurus
The most common Morrison sauropod, with different teeth and a different browsing height from Stegosaurus.
Same family
Close relatives
Other members of Stegosauridae.
- Not yet mapped
Kentrosaurus
An East African stegosaurid with more spikes and smaller plates, known from Tanzania's Tendaguru beds and roughly contemporary with Stegosaurus.
- Not yet mapped
Dacentrurus
A European stegosaurid from the Late Jurassic of Portugal, showing the family was geographically widespread.
- Not yet mapped
Hesperosaurus
A slightly earlier Morrison stegosaurid that helps fill in the North American family history before Stegosaurus itself appears.
Stegosaurus fossil discovery map
Pins show selected fossil records for Stegosaurus; use them as modern discovery evidence, not a complete range map. Modern fossil discovery map: pins show where selected fossil and specimen records were found today, not ancient Earth positions. What does this mean?
Modern Fossil Discovery Map
Specimen evidence
Museum images and 3D records
These are sourced specimen assets, separate from reconstruction artwork. Only media with clear open or reusable rights is displayed by default.
Specimen image
USNM V 8410_1
Michael Brett-Surman
CC0idigbio
View source 
Specimen image
USNM V 7380_4
Specimen from Department of Paleobiology, NMNH, Smithsonian Institution, Michael Brett-Surman
CC0idigbio
View source 
Specimen image
USNM V 7380_5
Specimen from Department of Paleobiology, NMNH, Smithsonian Institution, Michael Brett-Surman
CC0idigbio
View source 
Specimen image
USNM V 7380_3
Specimen from Department of Paleobiology, NMNH, Smithsonian Institution, Michael Brett-Surman
CC0idigbio
View source Research notes
Stegosaurus fossil map FAQ
Is this map where Stegosaurus lived?
No. The map shows modern fossil discovery locations from selected records. Ancient habitat and paleogeographic reconstructions are separate questions.
What formation is Stegosaurus associated with here?
The current Fossil Atlas records include Morrison Fm. Formation coverage depends on the selected dataset and may not be complete.
Can I make a Stegosaurus expedition card?
Yes. Use the expedition card generator to turn the Stegosaurus map and specimen profile into a shareable card.
Caveats
Important notes
Selected fossil records from PBDB and museum biodiversity aggregators. This is not a complete fossil count by country; source labels and confidence notes help distinguish canonical paleobiology records from specimen-media records.
Reconstruction images are labeled illustrations and do not represent fossil evidence. Size, speed, and bite-force figures are typical published estimates and remain subject to revision as new specimens are described.
Trust note
Selected source-backed records
Maps use curated PBDB, museum, and specimen-source records with visible caveats.
Trust note
Modern discovery locations
Pins show where fossils were found or reported today, not exact ancient habitat positions.
Trust note
Reconstruction is not evidence
Artwork is labeled separately from specimen photos, maps, and source records.
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