Dinosaur Quiz — 50 Questions for Grown-Ups

What does the name Tyrannosaurus rex mean?

Answer Tyrant lizard king

Tyrannosaurus means tyrant lizard and rex means king, so the full name is a superlative twice over. It was named in 1905, and the specimen that anchors the name is still in the American Museum of Natural History.

Triceratops is recognized by what?

Answer Three horns on the face and a large bony frill behind the skull

Three horns and a bony frill. What the frill was for is still argued: it is often shown as armor, but the bone is thin in places and many researchers read it as display and species recognition instead.

Stegosaurus carried what along its back and tail?

Answer Upright plates along the back and spikes at the end of the tail

Plates along the back and spikes at the tail tip. The spikes are called a thagomizer — a name that entered scientific use after appearing in a newspaper cartoon, which is unusual and true.

Which of these was a long-necked plant eater?

Answer Brachiosaurus

Brachiosaurus held its forelimbs longer than its hind limbs, so its shoulders sloped upward — the opposite of most sauropods. That build is why it is drawn reaching high into trees.

What was distinctive about Ankylosaurus?

Answer Heavy armor over the body and a bony club at the end of the tail

Armor across the back and a club of fused bone at the tail. The club was heavy enough to break bone, and specimens show the tail's rear vertebrae locked together into a rigid handle to swing it.

Velociraptor was about what size?

Answer Roughly the size of a large turkey

About the size of a large turkey, and covered in feathers — quill knobs on the forearm bones show where they attached. The film version is much larger and closer to its relative Deinonychus.

Spinosaurus is best known for what feature?

Answer A tall sail of skin supported by long spines on its back

A tall sail held up by spines growing from the vertebrae. Its purpose is unsettled, and so is the animal's shape: Spinosaurus has been rebuilt several times as new material has come to light.

Which group did the duck-billed dinosaurs belong to?

Answer Hadrosaurs, plant eaters with broad flattened snouts

Hadrosaurs, whose jaws held hundreds of teeth packed into grinding batteries that replaced themselves continuously. That equipment made them the most successful plant eaters of the late Cretaceous.

Pterosaurs, the flying reptiles, were what?

Answer Close relatives of dinosaurs, but not dinosaurs themselves

Pterosaurs are close relatives of dinosaurs, not dinosaurs themselves. Their wing is a membrane stretched from an enormously elongated fourth finger — an entirely different solution from a bird's.

And the long-necked swimming reptiles such as plesiosaurs?

Answer Also not dinosaurs; a separate group of marine reptiles

Also not dinosaurs. Plesiosaurs are marine reptiles from a separate branch, and the habit of calling everything ancient and large a dinosaur hides how distant these groups actually are.

The age of dinosaurs is divided into which three periods, in order?

Answer Triassic, Jurassic, Cretaceous

Triassic, Jurassic, Cretaceous, in that order, spanning roughly 250 to 66 million years ago. Dinosaurs appear well into the Triassic rather than at its start.

In which period did Tyrannosaurus rex live?

Answer The late Cretaceous, at the very end of the age of dinosaurs

The very end of the Cretaceous, in the last two million years before the extinction. T. rex was among the last non-bird dinosaurs, not one of the first.

Stegosaurus and Tyrannosaurus are often drawn together. What is wrong with that?

Answer They are separated by more time than separates Tyrannosaurus from us

Stegosaurus was already extinct for tens of millions of years before T. rex existed. The gap between them is larger than the gap between T. rex and us, which is the single most useful fact for correcting dinosaur illustrations.

What was the arrangement of the continents when the first dinosaurs appeared?

Answer Mostly joined into a single landmass

The continents were joined into Pangaea. That is why the earliest dinosaur faunas look similar worldwide, and why later groups diverge as the landmass broke apart.

Why do so many dinosaur species turn up in North America, China and Argentina?

Answer Those places have accessible rock of the right age and a long history of searching them

Those places have exposed rock of the right age that researchers can reach and are funded to work in. The pattern reflects where we have looked, not where dinosaurs actually lived.

How long ago did the non-bird dinosaurs die out?

Answer About sixty-six million years ago

About 66 million years ago. The date is tightly constrained because the boundary layer can be dated directly from volcanic material within it.

What is the leading explanation for that extinction?

Answer A large asteroid impact, with the role of massive volcanism still debated

A large asteroid impact at Chicxulub, with the enormous Deccan volcanic eruptions in India debated as a contributing stress. The impact crater, the global debris layer and the timing all line up.

Did any dinosaurs survive it?

Answer Yes: birds are the surviving branch of the dinosaur family

Birds are the surviving branch. Every bird alive is a dinosaur in the same sense that every human is a mammal — not a metaphor but a position on the family tree.

Roughly how long did dinosaurs exist as a group?

Answer Well over one hundred million years

Well over a hundred million years, roughly 165 million for the non-bird groups. Humans and everything recognizably like us occupy a sliver of that by comparison.

Humans and non-bird dinosaurs overlapped for how long?

Answer Not at all; tens of millions of years separate them

Not at all. Tens of millions of years separate the last non-bird dinosaurs from the first humans, and the gap is far larger than the whole span of mammal dominance that followed.

What can a dinosaur's teeth tell you most reliably?

Answer Roughly what it ate, since cutting, crushing and stripping teeth differ in shape

Teeth are the most reliable guide to diet, because cutting, crushing and grinding leave different shapes and different wear. They also fossilize best, being the hardest tissue in the body.

How did the large sauropods stand and move?

Answer On four pillar-like legs, with the neck held out rather than upright like a giraffe's

On four pillar-like legs, with the neck held out rather than reared upright for long periods. Blood pressure requirements are part of why a permanently vertical neck is now considered unlikely.

Did dinosaurs lay eggs?

Answer Yes, and nests with eggs and young have been found for several kinds

Yes, and nests, eggs and hatchlings have been found together. Some sites show the same nesting ground used repeatedly, which is evidence of behavior rather than anatomy.

What is evidence that some dinosaurs lived in groups?

Answer Trackways of many individuals moving the same way, and bone beds with many of one species

Trackways with many individuals moving the same direction at the same time, and bone beds holding many animals of one species. Neither proves a herd on its own; together they are persuasive.

Why were the arms of Tyrannosaurus so short relative to its body?

Answer It is genuinely uncertain; several explanations are argued and none is settled

Genuinely uncertain. Proposals include holding prey, helping the animal rise from lying down, and simple reduction as the head took over the work — none is settled, and honest sources say so.

What does a bony crest, frill or plate most often suggest to researchers?

Answer Display and species recognition, sometimes with other roles argued alongside

Display and species recognition most often, sometimes with a secondary role. Structures that differ sharply between closely related species, and grow larger with maturity, tend to be signaling structures.

What do growth lines inside fossil bone allow?

Answer An estimate of how fast the animal grew and roughly how old it was

Growth lines work rather like tree rings, letting researchers estimate age and growth rate. That is how we know T. rex grew explosively as a teenager and slowed sharply near adult size.

How is a dinosaur's walking speed estimated?

Answer From trackways: the spacing of footprints against the animal's leg length

From trackways: the spacing of prints against estimated leg length gives a speed. The result is a snapshot of that moment, not the animal's top speed.

What is a gastrolith?

Answer A stone swallowed by the animal, thought to help grind food inside the body

A stone swallowed deliberately, thought to help grind food in the gut. Birds still do it, which is one of many small habits that connect them to their dinosaur ancestry.

Were any dinosaurs warm-blooded?

Answer Evidence points to high growth rates and active bodies in many groups, and the picture is not a simple yes or no

The evidence points to high growth rates and activity levels rather than a simple warm or cold answer. Many researchers place large dinosaurs somewhere between the two, a condition called mesothermy.

What has to happen for an animal to become a fossil?

Answer It must be buried quickly, usually in sediment, before it is scattered or decays

Rapid burial, usually in sediment, before scavengers and decay take the body apart. That is why floodplains and river deltas produce so many fossils and mountaintops produce so few.

Which parts of an animal survive as fossils most often?

Answer Hard parts: bones and teeth

Hard parts: bones and teeth. Soft tissue requires unusual chemistry to preserve at all, which is why every specimen with skin or feathers is treated as exceptional.

What is a trace fossil?

Answer Evidence of activity rather than the body itself: footprints, burrows, droppings

A trace fossil records activity rather than the body — footprints, burrows, eggs, droppings. They capture behavior, which bones cannot, and often come from animals we have never found the bones of.

Why is the fossil record described as incomplete?

Answer Only a tiny fraction of animals are ever buried and preserved, and only some of that is ever found

Only a tiny fraction of animals are ever buried, fewer still survive to be found, and we search a small part of the exposed rock. Absence of evidence is weak evidence of absence in this field.

How is the age of a dinosaur fossil usually established?

Answer From the rock layers around it, dated by their own methods

From the rock layers around it. Volcanic ash beds above and below can be dated radiometrically, and the fossil is bracketed between them.

Why is carbon dating not used on dinosaur bones?

Answer The method only reaches back tens of thousands of years, far short of what is needed

Carbon dating reaches back only tens of thousands of years, and dinosaur fossils are thousands of times older. There is no original carbon left to measure.

What is a holotype?

Answer The single specimen that formally anchors the name of a species

The holotype is the single specimen that anchors a species name. If later work splits the species, the name stays with whatever group contains that specimen — which is why holotypes matter far beyond their bones.

Many museum skeletons are casts rather than original bone. Why?

Answer Original material is heavy, fragile and needed for study, so casts stand in for display

Original material is heavy, fragile and needed for research. Casts can be posed, lent and touched, and the real bones stay in collections where they can be re-examined as methods improve.

What can preserved skin impressions show?

Answer The pattern and texture of scales or the presence of feathers

Skin impressions show the pattern and texture of scales, or the presence of feathers. They come from the sediment against the body rather than from the skin itself, which is why they are so rare.

How do researchers estimate what a dinosaur weighed?

Answer By modeling body volume from the skeleton and applying densities, which gives a range rather than one figure

By modeling body volume from the skeleton and applying a density. The method is transparent but sensitive to assumptions, which is why published weights for the same animal can differ by a factor of two.

What did fossils with preserved feathers change?

Answer Reconstructions: many theropods are now drawn with feathers rather than bare scaly skin

Feathered fossils changed reconstruction across the board. Many theropods are now drawn with feathers by default, and the question shifted from whether they had them to how far the trait extended.

How was Tyrannosaurus posed in older illustrations, and what changed?

Answer Upright with the tail dragging; it is now shown horizontal with the tail held off the ground

Older art posed it upright with the tail dragging on the ground. Trackways show no tail drag marks, and the posture is now horizontal with the tail as a counterweight to the head.

What happened to the name Brontosaurus?

Answer It was long treated as the same animal as Apatosaurus, then argued to be distinct again, and the question is still live

Brontosaurus was long treated as the same animal as Apatosaurus, so the name was dropped. A large analysis in 2015 argued the differences justify separating them again, and the name is back — provisionally.

The small hunting dinosaurs in a famous 1990s film were much larger than the real Velociraptor. Why?

Answer The film's animals resemble a larger relative, and the size served the story rather than the fossils

The film's animals are much larger than real Velociraptor and closely resemble Deinonychus. They also lack feathers, which the fossil evidence for that group now clearly supports.

What is the relationship between birds and dinosaurs?

Answer Birds are dinosaurs: they descend from small feathered theropods

Birds descend from small feathered theropods and sit inside the dinosaur family tree. There is no boundary where dinosaurs stop and birds start; the group simply continues.

Can the color of some feathered dinosaurs be estimated?

Answer Partly: microscopic structures in fossil feathers correspond to pigments, and some patterns have been reconstructed

Partly. Microscopic structures in fossil feathers correspond to pigment-bearing organelles in living birds, and their shape allows some colors to be estimated — with real uncertainty attached.

Why do the names and family trees keep being revised?

Answer New finds and new analyses change how species are grouped, and the arrangement is a conclusion rather than a fixed fact

New finds and new analytical methods keep changing how species relate. A revised family tree is the system working rather than failing, though it makes the popular names unstable.

How should a striking new claim about dinosaurs be read?

Answer As a proposal that will be tested; single papers overturn less than headlines suggest

As a proposal that will be tested. Single studies overturn less than headlines suggest, and the useful question is whether independent groups reach the same result.

What does the sail of Spinosaurus illustrate about reconstruction?

Answer Its shape and even the animal's lifestyle have been revised repeatedly as more material was found

Spinosaurus has been reconstructed several times, including a major revision to its limb proportions and tail. It is the clearest reminder that a museum mount is the current best reading, not a photograph.

What is the most useful habit for following this subject?

Answer Treating illustrations as the best current reading rather than a photograph of the past

Treat illustrations as the best current interpretation rather than settled fact. Almost every famous dinosaur image has been revised at least once, and the ones that have not simply have not been tested yet.