Transcript CH. 35

Mammals
I. Characteristics
A. Class Mammalia
Vertebrates that feed their
young with milk produced in
female mammary glands.
B. 4,ooo species
C. are the dominant land
animals on earth.
D. are ENDOTHERMIC.
E. have highly developed brains.
F. Have a 4- chambered heart.
G. Have a diaphragm (muscle
that aids in breathing.)
H. Have a single lower
jawbone; most species have 4
different types of teeth.
I. Most are viviparous
(young are born alive and
receive nourishment from the
mother during development.)
J. females feed young
milk secreted from the
mammary gland.
K. Body covered with
hair or fur.
L. Found in most habitats:
1. Saltwater and freshwater.
2. Some fly.
3. Burrow in the ground.
4. Polar regions.
5. Jungle regions.
M. Effects of other mammals
on man:
1. Transportation.
2. Food.
3. Clothing.
4. Some destroy crops.
5. Some carry disease.
N. Adaptations
Camouflage
white hare in white snow
Defense
porcupine spines
Warning
skunk stripes
II. Classification
There are 3 groups of
mammals based on
their type of embryonic
development.
1. Monotreme
a. Primitive egg layers. Oviparous
b. not completely endothermic.
c. Have a cloaca.
d. only 3 species exist today:
Spiny anteaters (2 species)
Duck-billed platypus
Duck-billed Platypus
2. Marsupials
a. pouched animals.
b. Young are born immature
and must crawl to a pouch on
the mother’s belly and attach
to a nipple to complete
development.
Opossum
Fetus
Birth
Emergence
Crawls to Pouch
Finds the Nipple
Attaches to Nipple
Growth
Young Kangaroo
c. about
250 species exist.
1. Kangaroo
2. Opossum
–Only one in N. America
3. Placental
a. carry young in the
uterus of the female until
it can survive. The uterus
is nourished by the
placenta.
1. A placenta is
the structure that
nourishes the
young.
b. there are more
than 20 orders of
placental
mammals.
Flying mammals- bats
Flesh eaters- lions and tigers
Water dwelling- whale(largest)
and dolphins
Elephant- largest land mammal
Primate- highest order(monkeys and
humans)
Ungulates- hoofed mammals (horse)
Aquatic Mammal