Chapter 43 Mammals Section 3 Diversity of Mammals

Mammalian Orders Mammals are classified into a single order of monotremes, 7 orders of marsupials, & about 18 orders of placental mammals

Monotremes Order Monotremata Egg-laying mammals Duckbill platypus- Australia- water resistent fur, webbed feet & flattened tail Spiny anteater- Australia- feed on ants & insects- sticky tongue

Marsupials Order Marsupialia Majority live in Australia, and some live in New Guinea Virginia opossum- only marsupial in USA Have pouch to raise young in

Placental Mammals Nearly 95% of all mammalian species are placental mammals

Order Xenarthra Anteaters, armadillos, & sloths Location: N. America, C. America, & S. America Xenarthra- “strange joints” Feed on insects or plants

Order Lagomorpha Rabbits, hares, & pikas Double row of upper incisors, with two large front teeth backed by two smaller ones Teeth grow throughout lifetime & adapted to herbivorous diet

Order Rodentia Rodents: squirrels, marmots, chipmunks, gophers, muskrats, porcupines, mice, & rats Rodent’s teeth consist of a few molars or premolars and two pairs of incisors that grow all of the rodent’s life

Order Primates Lemurs, tarsiers, monkeys, gibbons, apes, & humans Omnivores; large brains Forward-facing eyes for depth perception Grasping hands, feet, and tails

Order Chiroptera Mammals that truly fly- bats Wing- modified front limb with a membrane of skin that stretches between digits Use thumbs for walking, climbing, & grasping Small eyes & large ears for echolocation- active at night

Order Insectivora Shrews, hedgehogs, & moles N. America, Africa, & Europe Most have long, pointed noses that help them probe the soil for insects Have sharp teeth to grasp & pierce prey

Order Carnivora Animals that eat meat- carnivores Dogs, cats, raccoons, bears, hyenas, otters, seals, & sea lions Strong sense of smell and sight Strong jaws, large teeth, clawed toes Aquatic carnivores- pinnipeds- sea lions, seals, walruses

Order Artiodactyla Hoofed animals- ungulates Ungulates with even number of toes- artiodactyls- deer, cattle, giraffes, pigs, and camels Herbivores- most have rumen Molars are flat and large for grinding plants

Order Perissodactyla Ungulates with an odd number of toes- perissodactyls Horses, zebras, rhinoceros, & tapirs Location: Africa & Asia Have a cecum

Order Cetacea Whales, dolphins, porpoises Lack hind-limbs, have tails Totally aquatic, but evolved from land Breathe through modified nostrils- blowhole Use echolocation to locate prey, navigate, & communicate Toothed whales- dolphins, orcas, sperm whale

Order Sirenia Manatees and dugongs Herbivores Location: tropical seas, estuaries, and rivers Closely related to elephants- evolutionary speaking

Order Proboscidea Asian and African Elephant Largest living land mammal African elephant- 13,200 lbs Feed on plants for 18 hours each day Nose is modified into trunk for grasping “proboscis”

Other Orders The 12 orders just described include most of the familiar placental mammals. The 6 remaining orders contain just 1% of the mammalian species.

REVIEW!!! Which continent is a natural home of both monotremes and marsupials? Compare manatees to toothed whales.