32 intro to mammals - pdtechu.sqooltechs.com
TRANSCRIPT
MammalsKingdom 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 Teeth3. Endothermic (warm-blooded)4. Mammary Glands5. 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.
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 dietPredators have large caninesHerbivores 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?
MovementMammals 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?
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.