1. Mammalia

2. Mammal Evolution
Mammals are believed to have evolved from Reptiles during the late Jurassic period

3. Mammal Evolution
The first true mammal was a small, shrew-like organism that coexisted with Dinosaurs
Ex. Hadrocodium fossil found in Northern China in 2002

4. Mammal Evolution
Mammal’s inner-ear bones probably evolved from modified ancestral reptile jaw bones

5. 3 Major Reproductive Categories
Monotremes
Egg-laying mammals (Ex. Echidna + Platypus)

6. 3 Major Reproductive Categories
Marsupials
Embryos born very early and nurse from inside mother’s pouch (Ex. Kangaroo, Koala)

7. 3 Major Reproductive Categories
Placentals
Embryos develop inside the womb, receiving nutrients and O2 from the mother via the Placenta
Newborns fed milk from mammary glands.

8. Mammal Characteristics
Characterized by hair and mammary glands
Whales have very little hair

9. Mammal Characteristics
Mammalian brains are more developed and specialized (cephalized) than any other class of animals

10. Mammal Characteristics
All mammals have special sweat glands that are modified for producing milk, called Mammary glands

11. Mammal Characteristics
Mammals are Heterodontic
Teeth are differentiated
Used for biting, grinding, tearing and crushing
Ex. Incisors, molars, canines, etc.

12. Mammal Orders There are 19 orders of mammals
We will look at the characteristics of 14 of them
Order: Monotremata
Lay Eggs (Ex. Echidna, Platypus)
Order: Marsupiala
Young grow in pouch (Ex. Koala)

13. Order: Insectivora
Small pointed teeth, adapted mainly for eating insects
Ex. Moles, Shrews, Hedgehogs

14. Order: Rodentia Nearly 50% of mammals are rodents
Have no canine teeth, but two very larger incisors
Almost all are herbivores
Ex. Mice, Squirrels, Beavers

15. Order: Edentata
Have no teeth
Ex. Armadillos, Sloths, Anteaters

16. Order: Carnivora Very diverse group, Meat eaters
Canine teeth highly developed
Ex. Wolves, Bears, Raccoons, Otters, Skunks, Mongoose, Cats

17. Order: Serenia
Aquatic mammals that breathe through their mouth and nose
Herbivores
Ex. Manatees and Dugongs

18. Order: Chiroptera Forelimbs adapted for flight
May find prey by echolocation
Ex. Insectivorous Bats, Old World Fruit Bats

19. Order: Lagomorpha Large incisor teeth Hindlimbs larger than forelimbs
Ex. Rabbits and Pikas

20. Order: Cetacea Fully aquatic mammals Vestigial pelvic bones
Evolved from a wolf/bear-like land mammal

21. Order: Cetacea Highly developed brain Have a dorsal blow-hole
Ex. Toothed Whales, Baleen Whales

22. Order: Proboscidea
Nose and top lip are highly enlarged into a muscular trunk for grasping items
Ex. Elephants

23. Order: Primata Highly developed brains Often bipedal
Ex. Lemurs, Monkeys, Apes, Humans

24. Order: Primata Humans are relatively new primates
We appear to share a recent common ancestor with chimpanzees

25. Order: Artiodactyla Hooves with even-numbered toes
Many of them are ruminants with a 4-chambered stomach
Ex. Deer, Giraffe, Cattle, Pig, Camel, Hippo

26. Order: Perissodactyla
Have odd-numbered toes
Ex. Horses, Tapirs, Rhinoceroses