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Ch. 43 - Mammals. Fossils show that mammals evolved nearly 200 million years ago. Age of Mammals Cenozoic Example of mammalian development was the horse. 4 toes 3 toes 1 toe. Mammal Characteristics. 1. Hair 2. Endothermic 4-chambered heart Diaphragm to aid in breathing
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Ch. 43 - Mammals • Fossils show that mammals evolved nearly 200 million years ago. • Age of Mammals Cenozoic • Example of mammalian development was the horse. • 4 toes 3 toes 1 toe
Mammal Characteristics • 1. Hair • 2. Endothermic • 4-chambered heart • Diaphragm to aid in breathing • Mainly viviparous • Mammary glands • Highly developed brain • Video
What are some advantages of endothermic vs. ectothermic? • Hunt at night • Regulate their own body temperature • More efficient • How does hair help mammals? • Insulation • How does the diaphragm & 4-chambered heart help mammals? • More efficient and higher metabolic rates to help maintain a constant body temperature.
Types of teeth in mammals • 1. Incisors – bite & cut • 2. Canines – grip, puncture, & tear • 3. Bicuspids – shear & shred • 4. Molars – grind & crush • Why are the shapes & sizes of teeth different in mammals?
What is viviparous? • Bear live young, in which the females care for and nourish the young. • How do the females provide nourishment for their young? • Mammary glands (milk)
Classification • 3 main groups of mammals • 1. Placental mammals – they nourish their young in the uterus through the placenta. • Most mammals • 2. Monotremata – egg-laying mammals • 3. Marsupialia – pouched mammals • Mainly in Australia
Mammal Orders • 1. Monotremata • The only order of mammals that is oviparous (egg laying). • Duck-billed platypus & spiny anteater • Video • 2. Marsupialia • These mammals are born before their development is complete. Thus, the newborns use their front legs to pull themselves into the mother’s pouch. Inside the pouch are mammary glands for them to feed on. • Video
Placental Mammals (Orders) • What is a placenta? • An organ that allows nutrients and oxygen to get to the fetus through the mother’s blood. • What is the period of development in the mother’s uterus called? • Gestation period • Human’s is 9 months • More advanced mammals have longer gestation periods.
3. Insectivora • Shrews, moles, & hedgehogs • Shrews are the smallest mammals • Mole’s fur goes both ways. Why? • Video • 4. Rodenta • Largest mammal order • Squirrels, chipmunks, gophers, mice, rats, beaver • What’s the largest rodent in N. America? • Beaver • Video
5. Lagomorpha • Rabbits & hares • 4 upper incisors instead of 2 • Video • 6. Edentata • Means “without teeth” • Anteaters, armadillos, & sloth • Video • 7. Chiroptera • Bats • Only mammals capable of true flight. • What is echolocation? • Video
8. Cetacea • Whales & dolphins • Breathe through a blowhole • Video • 9. Sirenia • Manatees & dungongs • Video • 10. Carnivora • Dogs, cats, raccoons, wolves, bears, lynx, mountain lions, tigers, weasels, ect. • Have large canines (mainly carnivores) • Video • 11. Pinnipedia • Sea lions, walruses, & seals • Video
12. Perissodactyla • Have an odd # of toes (ungulates) • Ungulates are hoofed mammals. • Horses, zebras, rhinos • Video • 13. Artiodactyla • Even # or ungulates & rumen • Deer, elk, bison, cows, moose, pigs, sheep, giraffes, camels, antelope, ect. • Video • 14. Proboscidea • Trunk nosed mammals • Elephants. • Video
15. Primates • Monkeys, apes, & humans • Chimps are 97.9% same genes as humans. • Video • Human Classification • Kingdom: Animalia • Phylum: Chordata • Class: Mammalia • Order: Primate • Family: Hominidae • Genus: Homo • Specific epithet: sapien
Mammals Heart • Draw out the following parts: • R. Atrium, R. Ventricle, L. Atrium, L. Ventricle, Vena Cava, Tricuspid, Semilunar valves, Lungs, bicuspid, aorta, arteries, veins, capillaries.
What are the differences in the vertebrate’s hearts? • 2 –chambers? • Fish, larva amphibian • 3-chambers? • Reptile(divided some), adult amphibian • 4-chambers? • Birds, mammals
Respiratory Systems • Fish gills • Amphibians gills, lungs, skin • Reptiles lungs • Birds lungs • Mammals lungs & diaphragm
Nervous System • The bigger & more complex the vertebrate the larger the brain. • All vertebrates use kidneys as an excretory system.
Reproductive Systems • External Fertilization • Fish & Amphibians • Internal Fertilization • Reptiles, Birds, & Mammals • Oviparous birds, some reptiles • Oviviparous some reptiles • Viviparous mammals