Key Ideas
Level 1

• After the dinosaurs died, mammals began to grow and change.
• Some mammals have live babies, some carry babies in pouches, and some lay eggs.
• Being small helped mammals survive in a world recovering from the asteroid.
• Mammals started living in many different places and eating many kinds of food.

Level 2

• Mammals diversified rapidly after the Cretaceous–Paleogene extinction because ecological niches left empty by dinosaurs became available.
• Three main lineages evolved: placentals (live birth), marsupials (pouches), and monotremes (egg-laying).
• Small size and flexibility in diet, reproduction, and habitat gave mammals a survival advantage in post-extinction ecosystems.
• Mammalian diversification laid the foundation for modern ecosystems and eventually allowed humans to evolve.

Schedule

Day One	Day Two	Day Three	Day Four
Main Lesson and/or Story	Spine Reading	Literature Extension	Extension Videos or Books
Hands On Activity	Art Extension		Try something for "Other Activities"
Narration Page or Coloring Page	Notetaking Extension	ELA: Sentence Expansion	ELA Page: Choose Another One

Hands-On Activity
Survival Simulation

Materials

• A variety of small toys or animal figurines (representing different mammals, dinosaurs, and other creatures)
• Paper or sticky notes to label traits (e.g., “Small size,” “Can hide,” “Flexible diet”)
• Timer or dice
• Optional: tray or area with “safe zones” and “danger zones”

Timeline Entries
c. 66 million years ago
Mammals Take the Stage
After the mass extinction that ended the reign of dinosaurs, mammals diversified rapidly. Small size, flexible diets, and different reproductive strategies (placental, marsupial, and monotreme) allowed mammals to survive and thrive, laying the groundwork for modern ecosystems.

Discussion Questions
Level 1

1. What happened to mammals after the dinosaurs disappeared?
   Sample answer: They started to grow, change, and live in more places.
2. Why was being small helpful for mammals?
   Sample answer: Small animals could hide and survive better when the environment changed.
3. Can mammals lay eggs or do they always have live babies
   Sample answer: Some lay eggs (like monotremes), some carry babies in pouches (marsupials), and some have live babies (placentals).
4. What kinds of places can mammals live?
   Sample answer: Forests, deserts, oceans, and many other habitats.

Level 2 

1. Why did mammals diversify after the dinosaurs went extinct
   Sample answer: Many ecological niches were empty, so mammals could adapt to new environments and foods.
2. What are the differences between placental, marsupial, and monotreme mammals?
   Sample answer: Placentals have live babies that grow inside the mother, marsupials have pouches, and monotremes lay eggs.
3. How did small size help mammals survive in a post-dinosaur world?
   Sample answer: Small mammals could hide from predators, survive on less food, and adapt to changing climates.
4. How did mammals eventually take over ecosystems after the extinction?
   Sample answer: By filling empty niches, evolving new traits, and reproducing successfully, mammals became dominant land animals.