Dinosaurs & Prehistoric Life · Unit 10
Life Before the Dinosaurs
From the first cells to trilobites, fish and the Great Dying
Dinosaurs occupy the last fifth of the history of complex life. Almost everything interesting about the origin of animals happened before they existed.
The unit covers the first life, the Cambrian explosion, fish and the move onto land, the Permian world, and the Great Dying - a far larger extinction than the one that killed the dinosaurs.
This unit breaks down into 19 short steps and 112 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
- 19
- Questions
- 112
- Difficulty
- 2-4
What this unit covers
- Life in the Permian
- The Cambrian Explosion
- The Great Dying
- Fish and the Move to Land
- The First Life
Where this fits
Best after The Age of Dinosaurs, so the timeline is already in place.
Where people slip
The end-Permian extinction killed a far larger share of species than the end-Cretaceous one. The dinosaurs' extinction is famous; it is not the worst on record.
How the unit is structured
Life Before the Dinosaurs runs as 19 short steps that unlock in order. 14 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.
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 112 in the unit altogether.
Fish and the Move to Land
- Fact or fibLevel 2
1. Land plants appeared before land animals.
Answer: True
True. Plants provided the food and shelter that animals needed.
- Multiple choiceLevel 2
2. Which period is called the Age of Fishes?
- The Devoniancorrect
- The Jurassic
- The Cretaceous
- The Cambrian
The Devonian saw an enormous variety of fish fill the seas.
- Put in orderLevel 2
3. Put these steps of life moving onto land in order.
Answer: Plants colonise the land -> Insects and other invertebrates follow -> Fish with strong fins reach the shallows -> Four-legged animals walk on land
Plants came first, then invertebrates, then fish with sturdy fins, then four-legged animals.
- True or falseLevel 2
4. The first four-legged animals evolved from lobe-finned fish.
Answer: True
True. Sturdy fleshy fins became limbs.
- Type the answerLevel 2
5. What word means a four-limbed vertebrate, including amphibians, reptiles, birds and mammals?
Answer: tetrapod
Tetrapod means four feet.
- Choose all that applyLevel 3
6. Which challenges faced the first land animals? Pick all that apply.
- Supporting weight without watercorrect
- Avoiding drying outcorrect
- Breathing air efficientlycorrect
- Coping with lower gravity
Gravity, drying out and breathing air all had to be solved.
Life in the Permian
- Choose all that applyLevel 2
7. Which animals lived before the dinosaurs? Pick all that apply.
- Trilobitescorrect
- Dimetrodoncorrect
- Giant dragonfliescorrect
- Tyrannosaurus
Trilobites, Dimetrodon and giant dragonflies all came earlier.
- Fill the blankLevel 2
8. During the Permian all the continents joined into the supercontinent ____.
- Pangaeacorrect
- Australia
- Atlantis
- Eurasia
Pangaea formed by the end of the Permian.
- Multiple choiceLevel 2
9. Which giant insects flew in the coal swamps before the dinosaurs?
- Giant dragonfly relativescorrect
- Giant bees
- Giant butterflies
- Giant mosquitoes only
Dragonfly relatives with wingspans up to about seventy centimetres flew in the Carboniferous.
- True or falseLevel 2
10. Coal is formed from the remains of ancient swamp forests.
Answer: True
True. Carboniferous means coal-bearing.
- Type the answerLevel 2
11. Which sail-backed animal of the Permian is often mistaken for a dinosaur?
Answer: Dimetrodon
Dimetrodon is more closely related to mammals than to dinosaurs.
- Choose all that applyLevel 3
12. Which animals were important in Permian ecosystems? Pick all that apply.
- Synapsidscorrect
- Large amphibianscorrect
- Early reptilescorrect
- Birds
Synapsids, amphibians and early reptiles all played major roles.
The Cambrian Explosion
- Fact or fibLevel 2
13. Dinosaurs lived at the same time as trilobites.
Answer: False
False. Trilobites died out about twenty million years before the first dinosaurs.
- Fill the blankLevel 2
14. Trilobites lived in the ____ for hundreds of millions of years.
- seacorrect
- desert
- forest
- sky
They were entirely marine animals.
- Multiple choiceLevel 2
15. Which armoured sea creature is the classic Cambrian fossil?
- The trilobitecorrect
- The dolphin
- The starfish only
- The crocodile
Trilobites crawled the sea floor for hundreds of millions of years.
- True or falseLevel 2
16. Eyes and hard shells first became common during the Cambrian.
Answer: True
True, and both changed how animals hunted and hid.
- Type the answerLevel 2
17. Which extinct armoured sea animal is the most famous Cambrian fossil?
Answer: trilobite
Trilobites are found worldwide and are prized by collectors.
- Choose all that applyLevel 3
18. Which features became widespread during the Cambrian? Pick all that apply.
- Mineralised shellscorrect
- Complex eyescorrect
- Burrowing into sedimentcorrect
- Powered flight
Hard shells, eyes and burrowing all spread rapidly.
The First Life
- Fact or fibLevel 2
19. Early Earth's air had very little oxygen in it.
Answer: True
True. Breathable oxygen built up slowly over billions of years.
- Fill the blankLevel 2
20. Microbes that make food from sunlight use a process called ____.
- photosynthesiscorrect
- digestion
- fermentation
- evaporation
Photosynthesis converts sunlight into chemical energy and releases oxygen.
- Multiple choiceLevel 2
21. What were the first living things on Earth like?
- Tiny single-celled organismscorrect
- Small dinosaurs
- Fish
- Trees
Life began as tiny single-celled organisms too small to see.
- True or falseLevel 2
22. For most of Earth's history, life was made only of microbes.
Answer: True
True. Complex animals are a late arrival in the story.
- Type the answerLevel 2
23. What are the layered mounds built by ancient microbes called?
Answer: stromatolites
Stromatolites are among the oldest fossils on Earth.
- Choose all that applyLevel 3
24. Which milestones occurred before animals appeared? Pick all that apply.
- Photosynthesis evolvescorrect
- Atmospheric oxygen risescorrect
- Complex cells appearcorrect
- Flowering plants appear
Photosynthesis, the oxygen rise and the origin of complex cells all came first.
The Great Dying
- Build the sentenceLevel 2
25. Build a sentence about life before dinosaurs.
Answer: Life existed long before dinosaurs
Life existed for billions of years before dinosaurs.
- Multiple choiceLevel 2
26. Roughly how many marine species died in the Great Dying?
- About nine in tencorrect
- About one in ten
- About half
- None
Estimates suggest around nine in ten marine species were lost.
- Sort into groupsLevel 2
27. Sort each event by whether it happened before or after the first dinosaurs.
Answer: The Cambrian explosion = Before; The Great Dying = Before; The rise of birds = After; The asteroid impact = After
The dinosaur story sits late in the history of life.
- Fact or fibLevel 3
28. Dinosaurs would probably never have risen without the end-Permian extinction.
Answer: True
True. It cleared the way for archosaurs to diversify.
- Put in orderLevel 3
29. Put these periods before the dinosaurs in order, oldest first.
Answer: Cambrian -> Devonian -> Carboniferous -> Permian -> Triassic
Cambrian, Devonian, Carboniferous, Permian, then the Triassic when dinosaurs appear.
- Choose all that applyLevel 4
30. Which effects made the end-Permian so lethal? Pick all that apply.
- Severe global warmingcorrect
- Widespread ocean anoxiacorrect
- Ocean acidificationcorrect
- A global ice sheet
Warming, ocean anoxia and acidification combined into a global crisis.
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 9 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
- Multiple choice
- Put in order
- Sort into groups
- True or false
- Type the answer
Practise Life Before the Dinosaurs
112 questions across 19 steps. Start with step one and crawl at your own pace.
Play this unitRead about Life Before the Dinosaurs
Explainers from our blog on what this unit covers. Each one ends with real questions from the bank.
More units in Dinosaurs & Prehistoric Life
- What Is a Dinosaur?What dinosaurs were, when they lived and how we name them
- Famous DinosaursTyrannosaurus, Triceratops, Stegosaurus and the other stars
- Meat Eaters and Plant EatersTeeth, claws, defences and what dinosaurs ate
- Fossils and Fossil HuntingWhat fossils are, how they form and how they are found
- The Age of DinosaursTriassic, Jurassic and Cretaceous, and how deep time works
- Eggs, Nests and Growing UpDinosaur eggs, nests, babies and family life
- Flying and Swimming ReptilesPterosaurs, plesiosaurs and the sea monsters that were not dinosaurs
- The Great ExtinctionThe asteroid, the volcanoes and who survived