Class Mammalia

1. Class Mammalia Pages 557 - 573

2. Class Mammalia • Mammalia is one of the smallest classes under Kingdom Animalia • However, it contains most of what we call “animals” today • Mammalia also contains humans • There are 26 orders under Class Mammalia (12 are under placental mammals)

3. Characteristics of Class Mammalia • 6 Main Characteristics: • Breathe air (they have lungs) • Are endothermic (warm-blooded: cold room does not equal cold mammal) • Have 4 chambers (sections) to their hearts • Have specialized teeth (different teeth for different jobs) • Produce (make) milk for their young • Have hair

4. Mammalia Hair • 2 Kinds of mammal hair: • Underhair: soft, insulating fur next to the skin; it keeps the animal warm • Guard hair: coarse (hard and strong), longer, and found over the underhair; gives the animal color • *Whiskers: a special kind of guard hair with nerves around the roots of the hair – these allow animals to feel what is around them • Some other guard hairs can also have nerves at the base and feel things

5. Digestion in Mammals • Mammals can be carnivorous (lions), herbivorous (cows) or omnivorous (humans) • Almost all mammals will have some kind of teeth • Different teeth do different jobs

6. Kinds of Teeth • Three basic kinds of teeth: • Incisors – flat, thin teeth at the front of the mouth used for gnawing or biting • Canines – rounded, pointed teeth toward the front of the mouth used for tearing • Molars – thick, squat teeth in the back of the mouth used for grinding and chewing

7. Digestion in Herbivorous Mammals • Herbivorous (plant eaters) have a special, longer digestive tract to let the food break down • Some, like the cow, have a rumen: a bag at the top of the stomach with spit, where the food goes to get wet • After being mixed with the spit, the cow will throw up the food into its mouth (food is now called cud) and chew it again to get it to break down even more

8. Cow Digestion VS. Horse Digestion

9. Digestion in Herbivorous Mammals • Some, like horses, have a cecum: an extra bag where the food sits in spit for an extra few hours to break down even more before becoming poop

10. Respiration in Mammals • All mammals will have lungs to breathe oxygen • These lungs are controlled by a muscle called a diaphragm • The diaphragm pulls the lungs down to pull air in and goes up to push air out • The air passes through a larynx inside the throat • The larynx gives the animal its voice

11. Circulation in Mammals • All mammals have 4 chambers in their hearts • The heart is very strong, like in Class Aves and Class Reptilia

12. Endothermic • All mammals are endothermic – they can control their own body temperature • Many mammals lose body heat through their skin, but some do other things • Dogs pant and lose heat through their tongues • Elephants can lose heat through their ears • Pigs and elephants can lose heat by rolling in the mud

13. Hibernating • Many mammals hibernate (sleep deeply in winter) • Squirrels and woodchucks will hibernate in winter – they sleep deeply, become very cold, and their body systems slow down, they can’t wake up easily • Bears and badgers become dormant – they sleep deeply, but they can wake up if they are bothered – they do not HIBERNATE!

14. Response in Mammals • Mammals have brains and can think for themselves • Mammals have memories and can learn well • Some mammals seem to show emotions • These things come from a part of the brain called the Cerebrum – the biggest part of the brain

15. Reproduction in Mammals • Mammals can reproduce one of three ways 1.) Placental Mammals – their babies develop (grow) inside the mother’s uterus and are connected to the mother through a placenta • The umbilical cord connects the baby to the placenta and is cut when the baby is born • Gestation is the name of pregnancy in these mammals • Cats, dogs, horses, humans • All of the orders we will study are placental mammals

16. Reproduction in Mammals 2.) Marsupial Mammals: mammals with pouches • Babies are made inside the mother, but do not have a placenta – they have a small yolk sac for food instead • After the yolk sac is gone, the babies go into a marsupium (pouch/bag) on the mother and drink her milk until they are old enough to be out on their own • Kangaroos, koalas, wombats, opossums • Marsupials usually live in Australia (but also China and America)

17. Reproduction in Mammals • Monotreme Mammals: mammals that lay eggs and sit on them to keep them warm until they hatch (ovoparous NOT viviparous) • Monotremes feed their babies with milk, but do not have nipples – their milk gets put onto their skin and the babies lick it off • The most common monotreme is the platypus

18. Order Rodentia • These mammals have well-developed, continuously growing incisors (flat, thin teeth at the front of the mouth) • If they don’t chew on something hard, those teeth can grow into their brains • Beavers, mice, squirrels

19. Order Carnivora • Well-developed canine teeth (rounded, pointed teeth used for tearing) • Claws on toes • Carnivorous • Cats, dogs, bears, lions, tigers

20. Order Pinnipedia • They have four fins (legs/arms for swimming) • Marine environments – they live in the water • Carnivorous • Seals, walruses

21. Order Catacea • Marine mammals – live in the water • Dorsal blowholes – a hole on the back used to breathe • Horizontal flukes – arms used for swimming on both sides of the body • Use echolocation – they send out sound waves to figure out what is in front of them • Whales, dolphins

22. Order Primates • Binocular vision – can see near and far away • Erect stature – they stand up and walk on their back legs • Opposable thumbs – their thumbs can bend to grab things • Apes, monkeys, humans

23. Order Perissodactyla • Odd-toed ungulates – mammals with hooves that either have one toe or three toes • They have a cecum – a bag where food sits in spit to break down • Herbivorous – they only eat plants • Horse, donkey, zebra, rhinocerous

24. Order Artiodactyla • Even-toes ungulates – have hooves with two toes • They can have a cecum or rumen (bag on top of the stomach where food gets spit put on before being thrown up into the mouth to be chewed again) • Pigs, cows, hippopotamuses, deer

25. What did Jews eat? • Leviticus 11 told the Jewish people what to eat • Cloven footed beasts (even-toed hooves) • Chew the cud (have a rumen)

26. Order Edentata • Teeth undeveloped or absent (not there) • Unique (special) back vertebrae (hard, wide plates instead of round vertebrae) • Anteaters, armadillos, sloths

27. Order Chiroptera • Flying mammals • Use echolocation (they send out sound waves to figure out what is in front of them) • Bats

28. Order Insectivora • Mainly insectivorious (they eat insects) • Live underground • Shrews, moles, hedgehogs

29. Order Sirenia • Live in coastal areas (where the land and water meet) in tropical and semitropical waters (Hawaii, India, Vietnam, Philippians) • Called Sea Cows • Manatees, dugongs

30. Order Proboscidea • Long, boneless trunk (long nose) • Largest land mammals • Elephants and Mammoths • Mammoths are now extinct (they are all dead)