Class Mammalia

HAIR Mammalian Characteristics ENDOTHERMIC- Mammals produce body heat internally through metabolism. All mammals have hair. Insulates the body against heat loss. Serves as camouflage HAIR Mammary glands – nourish young Nutritious fluid that contains fats, proteins, sugars and antibodies!

Four-Chambered Heart Separated ventricles keep deoxygenated blood from diluting oxygenated blood. Allows more efficient pumping of blood through both circuits of circulatory system.

Monotremes Duck-billed Platypus Echidna • Only egg laying (oviparous) mammals • Mothers secrete milk through skin (no nipples). • Baby sucks milk from the fur.

Marsupials • Opossums, kangaroos, tasmanian devils and koalas are some examples. • Give birth to live young ( viviparous). • Premature young complete embryonic development while nursing in a maternal pouch.

Eutherian (Placental) Mammals • Longer period of pregnancy by completing embryonic development within the uterus. • Placental young are nourished through a placenta. • Fossil evidence suggests eutherians and marsupials diverged from a common ancestor 80 to 100 million years ago

Mammals Have Specialized Teeth Respiratory System Lungs of mammals have a larger surface area available for gas exchange than all other animals. The Diaphragm is a sheet of muscle below the rib cage. Contraction of the diaphragm draws air intothe lungs. Carnivores, such as this lion skull, have large, sharp incisor and canine teeth that are able to cut and tear flesh. Mammals Have Specialized Teeth Incisors - cut Canines - grip - puncture - tear Herbivores, such as the horse, have flat teeth that are useful for grinding grass and grain, which are the staples of their diet. Premolars - shear - shred - cut - grind Molars - grind - crush - cut

Baleen is thin plates of fingernail-like material that hang from the roof of the mouth. Baleen whales, such as the blue whale, do not have teeth.

Nervous System & Sense Organs The brain of a mammal is about 15 times heavier than the brain of a similarly sized fish, amphibian or reptile. Enlargement of the cerebrum accounts formost of the size increase The cerebrum Evaluates input from sense organs, controls movement, and initiates and regulates behavior.

Using a process called echolocation, bats emit high frequency sound waves, which bounce off objects, and then they analyze the returning echoes to determine the size, distance, direction and speed of the object.

TYPES OF MAMMALS (ORDERS) Insectivora Chiroptera Carnivora Primates

Perissodactyla Proboscidea Artiodactyla

Xenarthra Cetacea

Rodentia Lagomorpha