1. 1. Describe early mammals during the Triassic period.
Review
Bell Ringer:
1. Describe early mammals during the Triassic period.
2. How are mammalian hearts different from other animals’?
3. What are mammal’s two distinguishing features? 1

2. Copyright Pearson Prentice Hall
32-2 Diversity of Mammals
Photo Credit: ©Zefa (RM)/M. Botzek/Masterfile
Copyright Pearson Prentice Hall

3. Copyright Pearson Prentice Hall
Diversity of Mammals
The three groups of living mammals are:
monotremes
marsupials
placentals
Copyright Pearson Prentice Hall

4. Monotremes and Marsupials
Monotremes lay eggs.
Monotremes share two notable characteristics with reptiles:
The digestive, reproductive, and urinary systems all open into a cloaca.
Females lay soft-shelled eggs that incubate outside the body.
Copyright Pearson Prentice Hall

5. Monotremes and Marsupials
Only three species of monotremes exist today: the duckbill platypus and two species of spiny anteaters, or echidnas.
These animals are found in Australia and New Guinea.
Copyright Pearson Prentice Hall

6. Monotremes and Marsupials
Marsupials bear live young, but at a very early stage of development.
Young marsupials complete their development in an external pouch.
Copyright Pearson Prentice Hall

7. Copyright Pearson Prentice Hall
Placental Mammals
Placental Mammals
Placental mammals are named for an internal structure called the placenta, which forms when the embryo's tissues join with tissues from within the mother's body.
Copyright Pearson Prentice Hall

8. Biogeography of Mammals
How did convergent evolution cause mammals on different continents to be similar in form and function?
Copyright Pearson Prentice Hall

9. Biogeography of Mammals
Similar ecological opportunities on the different continents have produced some striking examples of convergent evolution in mammals.
Landmasses merged in the late Cenozoic, and mammals dispersed into new habitats.
Living mammals reflect the diversity that resulted.
Copyright Pearson Prentice Hall

10. Biogeography of Mammals
Convergent Evolution in Mammals
Nine-Banded Armadillo
Chinese Pangolin
Similar ecological opportunities on different continents have resulted in convergent evolution among these and other mammals. Mammals that feed on ants and termites evolved not once but five times in different regions. Powerful front claws; a long, hairless snout; and a tongue covered with sticky saliva are common adaptations in these insect- eating animals.
Common Echidna
Giant Anteater
Aardvark
Copyright Pearson Prentice Hall

11. Copyright Pearson Prentice Hall
Convergent Evolution
Copyright Pearson Prentice Hall

12. Monotreme and Marsupial BONUS: 1. Find a monotreme or marsupial.
Last Bonus of 9 Weeks.
Monotreme and Marsupial BONUS:
1. Find a monotreme or marsupial.
2. Illustrate the animal.
3. List the following facts:
Where it’s found.
What it eats.
Describe how it reproduces.
2 random facts. 12

13. Copyright Pearson Prentice Hall
32-2
Copyright Pearson Prentice Hall

14. Copyright Pearson Prentice Hall
32-2
Most mammals are
monotremes.
marsupials.
placental mammals.
placental marsupials.
Copyright Pearson Prentice Hall

15. Copyright Pearson Prentice Hall
32-2
Monotremes are the only group of mammals that
lay eggs
have hair.
feed their young with milk.
are endotherms.
Copyright Pearson Prentice Hall

16. Copyright Pearson Prentice Hall
32-2
Ant-eating mammals on different continents look similar to each other because they are all
a result of divergent evolution.
adapted to similar ecological opportunities.
recently evolved from a common ancestor.
evolved from an ant-eating reptile.
Copyright Pearson Prentice Hall

17. Copyright Pearson Prentice Hall
32-2
What is the function of the placenta?
production of milk
exchange of materials between fetus and mother
digestion of food
protection of a young mammal after birth
Copyright Pearson Prentice Hall

18. Video
Mammals Video 18

19. Remember: Ch. 32 Vocab. Quiz MONDAY Pig Dissection MONDAY
Practice
Independent Practice:
1. Complete 32-1 and 32-2 Review Sheets.
2. Marsupial or Monotreme BONUS
3. Study for ch. 32 vocabulary quiz MONDAY
Remember:
Ch. 32 Vocab. Quiz MONDAY
Pig Dissection MONDAY 19

20. Monotreme and Marsupial BONUS: 1. Find a monotreme or marsupial.
Last Bonus of 9 Weeks.
Monotreme and Marsupial BONUS:
1. Find a monotreme or marsupial.
2. Illustrate the animal.
3. List the following facts:
Where it’s found.
What it eats.
Describe how it reproduces.
2 random facts. 20