2. Characteristics of Mammals
• Endothermic-controlling metabolism & regulating heat
loss
• Hair-all mammals have it for insulation & protection
• Cool off by panting or sweating
• Two-loop circulatory system w/4-chambered heart
completely divided
• Several types of glands – salvia, sweat, oil, digestive
enzymes, hormones, milk & scent.
• Mammary glands – secret milk for young
• Diaphragm – muscle below lungs to aid in respiration
3. More Characteristics
• Single solid jawbone with specialized teeth according to
diet
• Pointed or chisel-like incisors
• Canines
• Premolars and molars
• Nervous System
• Cerebrum – largest part of brain – used for thinking &
learning.
• Medulla oblongata – controls involuntary bodily
functions
• Cerebellum – controls movement & coordination
4. Mammal Classification
• Placental mammals – give birth to live
young that have developed in uterus.
Nourished from placenta. The time of
development in the uterus is gestation.
• About 90% of all mammals are placental.
• There are 19 orders of placental
mammals.
5. More Common orders of
Mammals
Rodentia –rodents, squirrels
Edentata – anteaters, sloths,
armadillos
Lagomorpha – rabbits, hares
Insectivora – shrews, moles
Primates – lemurs, monkeys,
apes, humans
Chiroptera – bats –only flyer
Artiodactyla –even # toes
deer, elk, cattle, sheep
Perissodactyla – odd # toes
horses, zebras, rhinos
Cetacea – whales, dolphins
Sirenia – manatees, dugongs
Proboscidea – elephant – two
types African or Asian
7. Mammal classification
• Order Marsupialia –
viviparous
• Two births- 1st half inside
mother and 2nd half
grows in pouch on
outside of mother.
• Kangaroos, opossums,
koala
• Australia, New Guinea,
N. America
8. Mammal classification
• Order Monotremata –
• monotremes – oviparous
• Duck-billed Platypus
• Spiny anteater (echidnas)
• Found only in Australia,
Tasmania, New Guinea
• Only three species of
monotremes alive today.
