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50 free Stegosaurus trivia questions with answers — science & nature quiz, new questions added Aug 2026.
Stegosaurus is the dinosaur with the kite-shaped plates and the spiked tail, and almost everything about it has been argued over. This quiz covers the plates first: why Marsh named it 'roof lizard', the four different arrangements proposed over the decades, whether the plates were for display or cooling, and how many an animal actually carried. Then the tail: the four spikes, the Allosaurus vertebra with a spike-shaped hole in it, and how a Far Side cartoon gave the weapon its scientific name. There are questions on the famously small brain and the 'second brain' myth, the Bone Wars discoveries at Morrison and Como Bluff, the 1885 Garden Park skeleton that finally showed what the animal looked like, Sophie in London, Apex's record-breaking $44.6 million auction, the fourth-graders who made it Colorado's state fossil, and its bite force compared with a Labrador. Easy questions ask what the plates were and which predator hunted it; hard ones want newtons, plate counts and quarry names. Every answer was checked against Wikipedia's articles on Stegosaurus and the thagomizer, and each question carries the sentence that supports it. Our Dinosaurs, Tyrannosaurus Rex and Triceratops quizzes go further.
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Q 01What does the name Stegosaurus mean?
Roof lizard
Marsh thought the plates lay flat over the back like roof tiles; only later finds showed they stood on edge.
Q 02Stegosaurus lived during which period?
Late Jurassic
About 155 to 145 million years ago, roughly 80 million years before T. rex; the two never met outside cartoons.
Q 03Besides the western United States, Stegosaurus fossils have been found in which European country?
Portugal
A fragmentary specimen from the Lourinhã Formation was tentatively assigned to S. stenops in 2007.
Q 04What did Stegosaurus most likely eat?
Low plants such as ferns and cycads
Its small head and short neck suggest browsing no more than a metre up, unless it could rear on its hind legs as Robert Bakker proposed.
Q 05How many Stegosaurus species are universally recognised from the Morrison Formation?
Three
S. stenops, S. ungulatus and S. sulcatus; the original type species, S. armatus, turned out to be too fragmentary to use.
Q 06By 21st-century consensus, the tail spikes were for defence and the plates were for what?
Display, with cooling secondary
Grooves for blood vessels once suggested radiators, but a keratin covering and Kentrosaurus's spiky alternative weaken the cooling idea.
Q 07The largest S. ungulatus specimens measured about how long?
7.5 m
And weighed over five tonnes; S. stenops was a little smaller at around 6.5 metres.
Q 08Stegosaurus was first identified by Othniel Charles Marsh during which famous rivalry?
The Bone Wars
The first scraps came from north of the town of Morrison in 1877; Marsh briefly thought they belonged to a turtle-like aquatic animal.
Q 09Marsh initially believed the first Stegosaurus remains came from what?
An aquatic turtle-like creature
Hence 'roof lizard': he pictured the plates lying flat and overlapping like shingles.
Q 10Which body replaced the dubious type species S. armatus with S. stenops?
The International Commission on Zoological Nomenclature
Marsh had also lumped Diplodocus teeth and a theropod shin into the original specimen, which did not help.
Q 11Where was the nearly complete, articulated S. stenops skeleton of 1885 collected?
Garden Park, Colorado
Marshall Felch dug it up in labelled blocks near Cañon City; it included the first complete skull and throat ossicles.
Q 12What does the species name stenops mean?
Narrow-faced
S. ungulatus is the 'hoofed' one, named for its preserved foot, and S. sulcatus the 'furrowed' one.
Q 13The first ever mounted Stegosaurus skeleton went on display in 1910 where?
Yale's Peabody Museum
Richard Swann Lull mounted it with paired plates; it was rebuilt in 1924 with two staggered rows.
Q 21How many toes did each Stegosaurus hind foot have?
Three
The fore feet had five, but only the inner two carried a blunt hoof; pads behind the toes supported all four limbs.
Q 22What is the name for the arrangement of spikes on a Stegosaurus tail?
Thagomizer
It has no formal anatomical origin at all: it came from a joke in a newspaper cartoon.
Q 23Which cartoonist coined the name for the Stegosaurus tail-spike cluster in a 1982 Far Side strip?
Gary Larson
A Far Side caveman lecturer explains the spikes are named 'after the late Thag Simmons'; palaeontologist Ken Carpenter adopted it in 1993.
Q 14Which plate arrangement has been the prevailing view since the early 1960s?
Two rows of alternating plates
Some S. stenops fossils preserve the plates partly articulated in exactly that staggered pattern.
Q 15The paired double-row plate arrangement appeared in Charles Knight's 1901 painting and which 1933 film?
King Kong
Knight's 1897 illustration was the basis for the film's stop-motion Stegosaurus puppet.
Q 16How many plates and flat spines did a Stegosaurus carry?
Between 17 and 22
The largest sat over the hips and could be more than 60 cm wide and 60 cm tall.
Q 17Skin impressions from the related Hesperosaurus show the plates were covered in what?
Keratinous sheaths
That would have strengthened them and given sharp edges, but also insulated them, which argues against a radiator role.
Q 18The Stegosaurus braincase was no larger than that of which animal?
A dog
Marsh's 1880s endocast showed the smallest brain, proportionally, of any dinosaur then known, perhaps 80 grams in a 4.5-tonne animal.
Q 19Marsh noticed a large canal in the hip region of the spinal cord, spawning what popular idea?
A 'second brain' in the hips
The space could have held something 20 times bigger than the brain; in birds the same spot holds a glycogen body of uncertain function.
Q 20Which palaeontologist disputed the "second brain" myth in an article about the 1932 American Museum mount?
Barnum Brown
The 1932 New York mount was a composite of partial remains from Bone Cabin Quarry filled in with replicas.
Q 24How many tail spikes did S. stenops have?
Four
Marsh first credited S. ungulatus with eight, but re-examination found it had four too, each 60 to 90 cm long.
Q 25Articulated armour shows the tail spikes protruded which way?
Horizontally
That is not how most old illustrations drew them, and it makes a sideways tail-swipe far more dangerous.
Q 26What proportion of Stegosaurus specimens in one study had injuries to their tail spikes?
9.8%
That much trauma suggests the spikes saw real combat rather than serving only for show.
Q 27A tail spike fits perfectly into a punctured tail vertebra of which dinosaur?
Allosaurus
The spike went in from below at an angle, and remodelled bone shows the wound got infected.
Q 28A 2010 computer model put Stegosaurus's bite force at less than half that of which dog?
A Labrador Retriever
At 140 to 275 newtons it could snap green twigs but struggled with anything over 12 mm thick.
Q 29Which feature was probably unique to Stegosaurus and a few advanced relatives among ornithischians?
A beak running along much of the jaws
Flat extensions of the lower jaw would have hidden the teeth completely from the side; the front of the mouth had no teeth at all.
Q 30Given its short front legs, Stegosaurus's top speed is estimated at about what?
16 to 18 km/h
The stubby forelimbs and long hindlimbs gave it the distinctive rounded back and high-held tail.