Mammals
Kingdom Animalia
---Phylum Chordata
------Subphylum Vertebrata
---------Class Mammalia
What do you get when
you cross an elephant
with a fish?
swimming trunks
Characteristics
1. Hair (some marine mammals have very
little)
2. Specialized Teeth
3. Endothermic (warm-blooded)
4. Mammary Glands
5. Placenta (most)
6. Diaphragm - muscle that aids breathing
Evolution of Mammals
Mammals did not come to dominate until the
CENOZOIC ERA, after the dinosaurs became
extinct
Early mammals
were probably
rodent-like and
nocturnal
How do mammals stay warm?
Hair insulates most mammals
Some marine mammals have a layer of
subcutaneous fat (blubber)
What is the placenta?
Attached to the wall
of the uterus , it
provides the fetus
with nourishment.
The Birth of a Giraffe
What are mammary glands?
Only found in mammals, produce milk to
feed young.
How the Diaphragm Works
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
The canines of
predators are very
large and sharp, used
for tearing flesh
Digestion
Mammals have diverse diets.
Herbivores often have an extra stomach
chamber called a RUMEN to help them
digest plants
This chamber
holds
bacteria that
can digest
plant material
Circulation
Mammals have a 4 – chambered heart and
double loop circulation.
What other animals have a double loop?
Movement
Mammals are a diverse group. Some…
● Run
● Climb
● Dig
● Fly
● Swim
Legs are adapted to a particular
job
Reproduction
Most mammals give birth to live young.
There are two groups that are exceptions…
1. Monotremes (lay eggs)
2. Marsupials (develop young in a pouch)
Order Monotremata
● Egg laying mammals found only in
Australia
● Have reptilian characteristics (cloaca &
egg laying)
● Have mammalian features (hair,
mammary gland)
Examples: Duck Billed Platypus
and the Echidna
(also called a Spiny Anteater)
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
Marsupial Examples
Can you
name these
animals?
Kangaroo Birth
Placental Mammals
● Placental Mammals have a gestation
period (length of time in uterus)
● Domesticated animals have been kept
and bred by people - cows, dogs, pigs,
horses..etc
Very diverse group, you will need to know all
of the orders. This topic is on the next
presentation.