Chapter 32 - Mammals

Kingdom Animalia
---Phylum Chordata
------Subphylum Vertebrata
---------Class Mammalia

Characteristics of Mammals

1. Hair (some marine mammals have very little)
2. Specialized Teeth
3. Endothermic
4. Mammary Glands
5. Placenta (most)
6. Diaphragm - muscle that aids breathing

In addition, all mammals have three bones in the middle ear (malleus, incus, stapes)

Specialized Teeth

Incisors - biting
Canines - stabbing, holding
molars - crushing, grinding

Different types of mammals have different types of teeth - depending on their diet

Predators have large canines
Herbivores have large flat molars

Mammals have a four chambered heart and a double loop circulatory system

Mammary Glands - used to nurse young, produce milk

Types of Mammals

Monotremes (egg layers), Marsupials (pouch), Placentals (uterus)

Order Monotremata

Egg laying mammals found only in Australia
Have reptilian characteristics (cloaca & egg laying)
Have mammalian features (hair, mammary gland)


Duck-billed platypus lives in Australia, lays eggs and males have a venom gland


The spiny anteater, also known as the echidna

Order Marsupiala

Mammals bear their young in am immature state, babies develop in a pouch
Majority are found on Australia, opossums are found on other continents
Examples: Kangaroo, wallaby, tasmanian devil, koala (click to see pictures)

Placental Mammals

Alternative: Print out Mammal Orders Chart, fill in information from the presentation

Placental Mammals have a gestation period (length of time in uterus)
Placenta- membrane that allows nutrients to pass thru from mom to baby

Domesticated animals have been kept and bred by people - cows, dogs, pigs, horses..etc

Placental Mammal Orders

Rodentia - teeth specialized for gnawing, incisors grow continuously. Ex. Mouse, rat, beaver

Chiroptera- flying mammals (membrane wing), use echolocation. Ex. bats

Insectivora - mainly eat insects, long noses. Ex. shrew & mole

Carnivora - flesh eating hunters, large canines. Ex. dog, cat, fox, lion, bear, raccoon

( Pinnipedia - marine mammals that mate on land. Ex. Walrus, seal)

Primate - adapted for living in trees, intelligent, opposable thumbs. Ex. Chimpanzees, humans

Artiodactyla - type of ungulate (hoofed mammal), even toed, Ex, sheep, cow. Large rumen in stomach helps break down plant material.

Perissodactyla - type of ungulate, odd toed. Ex. horse, rhino. Plant material is digested in a cecum

Cetacea - marine mammals, use echolocation, have blowhole. Ex. whales & dolphins

Lagomorpha - one pair of long incisors, legs specialized for hopping. Ex. rabbits and hares

Sirenia - marine mammals that live in shallow water. Ex. Manatee & dugong

Proboscidea - named for their trunk, or proboscis, many have long tusks (incisor). Ex. elephants.

Xenarthran - Sloths, anteaters