Dinosaurs & Prehistoric Life · Unit 12

Dinosaur Family Groups

How dinosaurs are sorted into the great branches

The major dinosaur groups are defined by shared anatomical features rather than by appearance, which is why some superficially similar animals sit in different branches.

The unit covers the lizard-hipped and bird-hipped division, theropods, sauropodomorphs, ornithopods, and the ceratopsians and armoured dinosaurs.

This unit breaks down into 18 short steps and 107 questions, starting at difficulty 2 and building to 4. Below you can see exactly what it covers, how the path is structured, and worked examples with explanations.

Steps: 18
Questions: 107
Difficulty: 2-4

What this unit covers

Ceratopsians and Armoured Dinosaurs
Lizard Hips and Bird Hips
Ornithopods
Sauropodomorphs
Theropods

Where this fits

Follows Famous Dinosaurs. Classification and Cladistics is the methodological version.

Where people slip

Birds descend from the lizard-hipped branch, not the bird-hipped one. The hip names came first and turned out to be an unhelpful coincidence.

How the unit is structured

Dinosaur Family Groups runs as 18 short steps that unlock in order. 13 are practice rounds and 5 are challenge rounds that pull together everything before them. Questions start at difficulty 2 and climb to 4 as you progress.

Step 1 · easierStep 18 · harder

Challenge rounds

Example questions

30 real questions from this unit, with the answer and the reason behind it, grouped by what they practise. There are 107 in the unit altogether.

Ceratopsians and Armoured Dinosaurs

Sort into groupsLevel 2
1. Sort each dinosaur as lizard-hipped or bird-hipped.
Answer: Velociraptor = Lizard-hipped; Diplodocus = Lizard-hipped; Stegosaurus = Bird-hipped; Iguanodon = Bird-hipped
The two great branches split early in dinosaur history.
Build the sentenceLevel 3
2. Build a sentence about dinosaur groups.
Answer: Dinosaurs are grouped by shared features
Dinosaurs are sorted into groups by shared features.
Choose all that applyLevel 3
3. Which ornithischian groups are recognised? Pick all that apply.
- Ornithopodscorrect
- Ceratopsianscorrect
- Thyreophoranscorrect
- Sauropods
Ornithopods, ceratopsians, pachycephalosaurs and thyreophorans are all ornithischian branches.
Fact or fibLevel 3
4. Classification changes as new fossils and analyses appear.
Answer: True
True. The dinosaur family tree is a working hypothesis, not a fixed chart.
Match the pairsLevel 3
5. Match each dinosaur to its group.
Answer: Tyrannosaurus = Theropod; Brachiosaurus = Sauropod; Triceratops = Ceratopsian; Ankylosaurus = Armoured thyreophoran
Sorting dinosaurs into groups makes their family tree easier to follow.
Multiple choiceLevel 3
6. What do ceratopsians all have in common?
- A beak and a bony frillcorrect
- Wings
- A tail club
- Long necks
They share a parrot-like beak and a bony frill at the back of the skull.

Lizard Hips and Bird Hips

Choose all that applyLevel 2
7. Which dinosaurs are ornithischians? Pick all that apply.
- Triceratopscorrect
- Stegosauruscorrect
- Iguanodoncorrect
- Tyrannosaurus
Triceratops, Stegosaurus and Iguanodon are all bird-hipped dinosaurs.
Multiple choiceLevel 2
8. Traditionally, dinosaurs are split into two great groups based on what?
- The shape of their hipscorrect
- The colour of their scales
- The size of their eggs
- The country they lived in
The arrangement of the hip bones separates the two classic groups.
True or falseLevel 2
9. Birds evolved from the lizard-hipped group, not the bird-hipped one.
Answer: True
True, which makes the traditional names rather confusing.
Fact or fibLevel 3
10. Every ornithischian dinosaur we know of ate plants.
Answer: True
True. The bird-hipped dinosaurs were all herbivores or mostly so.
Fill the blankLevel 3
11. The hip bone whose direction defines the two groups is the ____.
- pubiscorrect
- femur
- skull
- rib
The pubis points forwards in saurischians and backwards in ornithischians.
Type the answerLevel 3
12. What does the group name Ornithischia mean?
Answer: bird-hipped
It means bird-hipped, from the backward-pointing pubis bone.

Ornithopods

Fill the blankLevel 2
13. Hadrosaurs are often called ____-billed dinosaurs because of their broad snouts.
- duckcorrect
- goose
- hawk
- crow
The wide flat snout resembles a duck's bill.
Type the answerLevel 2
14. Which ornithopod is famous for the large spike on its thumb?
Answer: Iguanodon
Iguanodon's thumb spike was first mistaken for a nose horn.
Choose all that applyLevel 3
15. Which are ornithopods? Pick all that apply.
- Iguanodoncorrect
- Edmontosauruscorrect
- Parasaurolophuscorrect
- Triceratops
Iguanodon, Edmontosaurus and Parasaurolophus all belong here.
Multiple choiceLevel 3
16. Which dinosaur group includes the duck-billed hadrosaurs?
- Ornithopodscorrect
- Sauropods
- Theropods
- Pterosaurs
Ornithopods include Iguanodon and the hadrosaurs.
True or falseLevel 3
17. Some ornithopods could walk on two legs or four.
Answer: True
True. Many switched depending on speed and feeding.
Put in orderLevel 4
18. Put these ornithopod stages in evolutionary order.
Answer: Small early ornithopods -> Iguanodonts -> Early hadrosaurs -> Crested hadrosaurs
Small early forms, then iguanodonts, then early hadrosaurs, then crested hadrosaurs.

Sauropodomorphs

Choose all that applyLevel 2
19. Which are sauropods? Pick all that apply.
- Diplodocuscorrect
- Brachiosauruscorrect
- Argentinosauruscorrect
- Deinonychus
Diplodocus, Brachiosaurus and Argentinosaurus are all sauropods.
Multiple choiceLevel 2
20. What do sauropods look like?
- Long necks and tails on four pillar legscorrect
- Two legs and huge jaws
- Armour plates and a tail club
- Horns and a frill
They have long necks, long tails, small heads and four pillar-like legs.
True or falseLevel 2
21. Plateosaurus was an early sauropodomorph from the Triassic.
Answer: True
True. It is one of the best known early members of the line.
Fill the blankLevel 3
22. The early two-legged relatives of sauropods are often informally called ____.
- prosauropodscorrect
- protoceratopsians
- pterosaurs
- placoderms
Prosauropods is an informal term for these early sauropodomorphs.
Type the answerLevel 3
23. What is the group name for all the long-necked plant eaters and their early relatives?
Answer: sauropodomorphs
Sauropodomorphs include sauropods and their earlier kin.
Choose all that applyLevel 3
24. Which features are typical of sauropods? Pick all that apply.
- Long neckscorrect
- Small heads for their bodycorrect
- Column-like legscorrect
- Grinding tooth batteries
Long necks, small heads, column-like legs and hollow vertebrae are all typical.

Theropods

Choose all that applyLevel 2
25. Which are theropods? Pick all that apply.
- Spinosauruscorrect
- Velociraptorcorrect
- A modern eaglecorrect
- Brachiosaurus
Spinosaurus, Velociraptor and modern birds are all theropods.
Multiple choiceLevel 2
26. Which theropod group had long legs and beaks and looked rather like ostriches?
- Ornithomimosaurscorrect
- Ceratopsians
- Stegosaurs
- Hadrosaurs
Ornithomimosaurs were fast, toothless runners.
True or falseLevel 2
27. Not all theropods were meat eaters.
Answer: True
True. Therizinosaurs and some others ate plants.
Fact or fibLevel 3
28. Theropods ranged from animals smaller than a chicken to fifteen metre giants.
Answer: True
True. No other dinosaur group covers such a size range.
Fill the blankLevel 3
29. Tyrannosaurus belongs to a theropod subgroup called the ____.
- tyrannosaurscorrect
- sauropods
- hadrosaurs
- ankylosaurs
Tyrannosaurs were the great predators of the late Cretaceous north.
Put in orderLevel 3
30. Put these theropod groups in order from most distant to closest to birds.
Answer: Ceratosaurs -> Allosauroids -> Tyrannosaurs -> Dromaeosaurs
Ceratosaurs are distant, then allosauroids, then tyrannosaurs, then dromaeosaurs closest.

Where these questions come from. Each unit starts as a plan of the concepts it should cover and the difficulty it should span. Questions are written against that plan with AI assistance, then checked by a validator that rejects anything without a single defensible answer, an explanation, or plausible wrong options. How we write questions sets out the whole process, and corrections are fixed in the bank and reach the site and the app the same day.

How you practise

This unit mixes 10 different question formats, so you are recalling and applying rather than recognising the same layout every time.

Build the sentence
Choose all that apply
Fact or fib
Fill the blank
Match the pairs
Multiple choice
Put in order
Sort into groups
True or false
Type the answer

Practise Dinosaur Family Groups

107 questions across 18 steps. Start with step one and crawl at your own pace.

Play this unit

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