1. Mammology Characteristics Orders Reps

2. Main Characteristics of mammals: Endothermy - maintain high, constant body temperature through their metabolism Pelage - hair or fur made of protein called keratin covering all or part of the body for insulation & camouflage Four chambered heart (two atria & two ventricles) keep oxygenated & deoxygenated blood from mixing; double circulation Mammary glands in females are modified sweat glands that make milk containing sugars, proteins, & fats to nourish young Single jawbone Specialized teeth for biting, cutting, & chewing Highly developed brain (large cerebrum)

4. EchidnaEchidna PlatypusPlatypus MonotremesMonotremes EchidnaEchidna PlatypusPlatypus MnotremesMnotremes Oviparous (egg laying) monotremes EchidnaPlatypus Oviparous Not completely endothermic (lower body temperature & it fluctuates) Have a cloaca where wastes, eggs, & sperm are emptied Includes duck-billed platypus & spiny anteaters or echidna

5. Monotremes

6. Viviparous (live birth) marsupials with incomplete uterine development Found in New Guinea, Australia, & the Americas Dominate animal in Australia due to lack of competition from placental mammals Known as pouched animals Pouch called marsupium Viviparous (live birth) Tiny, immature young must crawl to mother's pouch after birth Young attach to mammary gland nipple to nurse until able to survive outside of pouch Includes opossum, kangaroo, wombat, & koala

8. Placental Mammals Young carried in uterus & nourished by placenta Gestation periods (time of development within uterus) varies among species Adapted for life on land in water, and in air Mammal species make up 95 % of all animals

9. Specializations of the mouth & digestive system: Single jawbone Incisors - specialized, chisel like front teeth for biting & chewing Canines - pointed teeth or fangs behind incisors to help grip, puncture, & tear prey Bicuspids - teeth with two points behind the canines used to shear & shred food Molars - flattened back teeth to grind & crush Baleen - thin plates in the roof of the mouth of some whales that strain food from water Microorganisms living in the gut help some mammals digest cellulose from plants Hoofed mammals (cows, sheep, giraffes...) have a four-chambered stomach with bacteria living in the first chamber or rumen Cud - digested food in the rumen that is regurgitated, swallowed, & then chewed again to break down plant cellulose Caecum - stomach chamber in elephants, horses, & rabbits that contains bacteria to digest cellulose

10. Adaptations for Endothermy: High demand for oxygen Right & left sides of heart separated by septum so oxygenated & deoxygenated blood don't mix Left side of heart pumps blood to lungs & back (pulmonary circulation) Right side of blood pumps oxygenated blood to body cells (systemic circulation) Diaphragm - sheet of muscle below lungs that moves up & down in chest to change air pressure so gas moves into & out of the lungs Alveoli or air sacs in the lungs are surrounded by capillaries and increase the surface area for the absorption of oxygen Hair or fur and a fat layer insulates and prevents heat loss

11. Nervous System Adaptations: Largest vertebrate brain Cerebrum surface is folded to increase surface area without increasing volume Cerebrum controls sensory organs, coordinates movement, regulates behavior, & is responsible for memory & learning Have five major senses --- vision, hearing, olfaction (smell), touch, & taste Bats, whales, dolphins, porpoises use echolocation (bouncing off of high frequency sounds) to navigate & find prey

12. Reproductive Adaptations: Each of the 3 mammal groups --- monotremes, marsupials, & placentals--- has a unique reproductive pattern 1.Monotreme females lay 1-2 leathery- shelled eggs containing yolk & incubates them with her body heat Young monotremes are small & partially developed at hatching so depend on mother for protection and milk from mammary glands

14. 2. Marsupials have short development period inside of the mother & newborns must crawl to the mother's pouch or marsupium after birth, attach to a nipple for milk, and finish developing

16. 3. Placentals are the largest group of mammals Gestation (period of development inside mother) is longer in placental mammals Nutrients, wastes, gases exchanged through membrane lining uterus called the placenta

17. 18 Orders exist Order Insectivora: Includes moles, hedgehogs, & shrews Small with high metabolic rate Found in North America, Europe, & Asia Have long, pointed noses to grub for insects & worms Teeth adapted to pick up & pierce prey Adapted to live on & under ground, in trees, and in water Shrews feed above ground & have claws to help sweep invertebrates into their mouths Moles live underground, have reduced eyes & no external ears, and have short limbs to dig tunnels

18. Order Rodentia: Largest mammal order (40% of all species) Found everywhere except Antarctica Includes squirrels, chipmunks, gophers, rats, mice, & porcupines Have two instead of four incisors Teeth continue to grow throughout their life Feed on hard seeds, twigs, roots, & bark Gnawing keeps incisors sharp High reproductive capacity Guinea pig & capybaras are two rodents found in South America

19. Order Lagomorpha: includes rabbits, hares, & pikas Found worldwide Have a double row of upper incisors & two large front teeth backed up by two smaller teeth Continuous growing teeth Herbivores

20. Order Edentata: Includes anteaters, armadillos, & sloths Found in North, Central, & South America Means "without teeth" Only anteaters are completely toothless Armadillos & sloths have peg-like teeth without enamel Have long sticky tongues & claws on powerful front paws to open ant hills & termite nests Sloths are herbivores Armadillos eat small reptiles, frogs, mollusks, & dead animals

21. Order Chiroptera: Only flying mammals Includes bats found everywhere except polar regions Front limb is modified into a wing with a skin membrane stretching from the finger bones to the hind limb Clawed thumb, extending from top edge of wing, is used for walking, climbing, & grasping Most are nocturnal (night active) Use echolocation (emission of high frequency sounds that bounce off objects) to navigate and locate food Have small eyes & large ears Feed mainly on insects Tropical bats don't use echolocation, but have large eyes & keen sense of smell to find fruit to feed on & nectar

22. Order Cetacea: Includes whales, dolphins, & porpoises Most inhabit oceans, but some dolphins live in freshwater rivers Have a fish shaped body Forelimbs modified as flippers No hind limbs Broad, flat tails to propel through water Breathe through a blowhole on top of the head Divided into two groups --- toothed whales & baleen whales

23. Toothed whales: 1. Includes beaked, sperm, beluga, & killer whales; narwhals; dolphins; porpoises 2. Have 1 to more than 100 teeth 3. Prey on fish, squid, seals, & other whales

24. Baleen whales: 1. Lack teeth 2. Includes blue, grey, right & humpbacked whales 2. Have baleen or thin plates of fingernail like material that hangs from the roof of the mouth 3. Baleen strain shrimp & other invertebrates from water as food

25. Order Sirenia: Includes manatees & dugongs Large herbivores Inhabit tropical seas, estuaries, & rivers Front limbs modified into flippers No hind limbs Flattened tail for propulsion

26. Order Carnivora: Found worldwide Includes cats, dogs, raccoons, bears, hyenas, & otters Meat eaters (carnivores) mainly Many feed on both plants & animals (omnivores) Have long canine teeth & strong jaws Clawed toes for seizing & holding prey Keen sense of sight & smell Long limbs for running fast

27. Order Pinnipedia: Aquatic carnivores Includes sea lions, seals, & walruses Streamlined bodies adapted for swimming Steer & propel through water using broad, flattened tail Called pinnipeds Return to land to feed & give birth Spend much of their time in cold water Large land carnivores so this helps maintain endothermy Can remain under water for 5 minutes to an hour for some species

28. Order Artiodactyla: Known as ungulates or hoofed mammals Have an even number of toes Includes deer, elk, bison, moose, sheep, cows, caribou, goats, pigs, & camels Herbivores Have large flat molars for grinding plants Found everywhere except Antarctica Cloven or split hooves Fast runners (used for defense) Have storage chamber called rumen in stomach where bacteria break down cellulose Stored food called cud is chewed again & then swallowed to go through digestive system a second time

29. Order Perissodactyla: Odd toed ungulates Includes horses, zebras, rhinoceroses, & tapir Most are native to Africa & Asia Tapirs are found in Central & South America Have a large, convoluted caecum or blind sac near the small intestine where bacteria digest cellulose

30. Order Proboscidea: Have a boneless trunk or proboscis Includes the African & Asian elephant Wooly mammoth is an extinct member of this order Largest terrestrial mammal Weigh more than 6 tons Feed on plants up to 18 hours a day Proboscis used to gather leaves from high branches & to suck water without lowering the head Modified incisors called tusks help dig for roots & strip bark Jagged molars up to 30 cm long grind plants Have the longest gestation period (20 months for females & 22 months for males) Females can continue to have calves until they are 70 years old

31. Order Primates: Includes 2 main groups --- Prosimians & Anthropoids Most are omnivores Have teeth suitable for a varied diet Prosimians include lemurs, tarsiers, & lorises Anthropoids include monkeys, apes, & humans Anthropoids have a larger brain Show more complex behaviors than other animals Highly organized social groups Gorilla is the largest primate Have 2 forward-facing eyes for depth perception Have grasping hands & most with grasping feet Some have a grasping tail for life in trees Live in a variety of habitats

35. Placental Edentata (armadillos, anteaters, and tree sloths) Insectivores (moles, hedgehogs, shrews) Chiroptera (bats) Primates (lemurs, monkeys, apes) Carnivores (wolves, dogs, coyotes, lions, tigers, raccoons, weasels (includes otters, minks, skunks, pandas and bears, seals, sea lions, and walruses)

36. More Placental Ungulates - (Hoofed Mammals) sheep, goats, camels, pigs, cows, deer, giraffes, and antelopes, rhinos, tapirs, horses Cetaceans - Whales, Dolphins, and Porpoises Proboscideans – Elephants Sirenians – Manatees Lagomorphs -hares, rabbits, and pikas