Your learner is about to discover an incredible time when plants became giants and insects ruled the skies! In the Carboniferous Period, swampy forests covered the Earth, and the air was so rich with oxygen that dragonflies grew to the size of eagles. It's a fascinating window into how plants transformed our entire planet, and set the stage for animals to follow them onto land.

Key Ideas

• Carboniferous plants developed roots, leaves, and vascular systems, allowing them to grow tall and change the environment.

• The increase in oxygen and creation of soils made it possible for larger land animals and insects to thrive.
• Animal evolution responded to plant expansion: amphibians adapted to land, and early reptiles evolved to live further from water.

Spines

• DK's Science as You've Never Seen it Before: Carbon Fossil Fuels pg. 37

• Visual Timelines: Life on Earth pg. 40-45
• Alternatives:
  • Kiddle: Carboniferous
     

✏️  Notebooking Activity Look at the graph in the workbook: what could we label the x and y axes that would make sense for the Carboniferous period? (Hint: think about what happened to insects during this time.) As __________ increased, __________ also increased.

Cosmic CalendarWhere we are: December 21 to 22
The Carboniferous covers two cosmic days. Read the script below before the lesson.

Read aloud: December 21st and 22nd on our Cosmic Calendar. We’re deep into the final stretch of the year now. The Carboniferous Period, roughly 359 to 299 million years ago, is when land really gets going. Huge forests of ferns and scale trees cover the continents. Giant insects patrol the air. Amphibians are everywhere, and early reptiles are learning to lay eggs on dry land. The coal we burn today, the fuel that powered the Industrial Revolution, was made from the forests of this exact period. Those ancient trees fell into swamps and were buried and compressed over millions of years into coal. Two calendar days. That’s the Carboniferous. We’re running out of days quickly, and so much is still to come.
Timeline EntriesLabel the next page in your timeline “Life Moves to Land: 360 Million Years Ago”. The workbook prompt asks learners to draw a dense Carboniferous coal forest, adding towering club mosses, giant ferns, and enormous dragonflies filling the air above.

Discussion Questions

1. What kinds of plants grew during the Carboniferous? 
   Sample answer: Big ferns, horsetails, and club mosses.
2. How did plants help animals move onto land? 
   Sample answer: Plants made food and homes for animals to live on land.
3. Why do you think insects were so big back then? 
   Sample answer: There was more oxygen in the air, so insects could grow bigger.
4. How did the evolution of roots, leaves, and vascular systems in plants change the Earth's environment? 
   Sample answer: Roots stabilized soil, leaves allowed plants to grow taller and capture sunlight, and vascular systems carried water and nutrients, creating forests that transformed the landscape.
5. Why did higher oxygen levels allow larger animals and insects to exist? 
   Sample answer: More oxygen made it easier for bodies to get enough air to support bigger muscles and bigger bodies.

Digging Deeper

• Can you think of modern examples of plants changing the environment for animals? 
  Sample answer: Rainforests create homes and food for many animals; coral algae support reefs and the animals that live there.

Vocabulary

• Carboniferous — A period (about 359-299 million years ago) of vast swamp forests that eventually became coal.
• Reptile — A vertebrate with scales and amniotic eggs; the first reptiles evolved during the Carboniferous and could live fully on land.
• Amniotic Egg — An egg with a protective membrane and shell that prevents drying out; allowed reptiles to reproduce entirely on land.
• Spore — A tiny reproductive cell released by plants and fungi; early land plants like ferns reproduced with spores.
• Coal — A fossil fuel formed from compressed plant material that accumulated in vast Carboniferous swamp forests over millions of years.
• Swamp — A wetland habitat with standing water and dense vegetation; Carboniferous swamps were filled with giant ferns.
• Adaptation — A physical feature or behavior that helps an organism survive in a specific environment, developed through natural selection.

Species to ResearchThe Carboniferous was the age of giant insects and vast coal forests. Here are some species to research:

• Meganeura— A dragonfly-like insect with a wingspan up to 70 cm; the largest flying insect to ever live.
• Arthropleura— A giant millipede-like arthropod that could reach 2.5 meters; fed on decaying plant matter in Carboniferous forests.
• Hylonomus— One of the earliest known true reptiles; laid eggs on land and was freed from needing water to reproduce.
• Lepidodendron— A giant club moss tree that grew up to 30 meters; formed the vast coal forests of the Carboniferous.
• Westlothiana— An early amniote that may be one of the first true reptiles; found in Scotland.
• Eryops— A large early amphibian that spent time on land; one of the dominant terrestrial animals of its time.