Class Mammalia All mammals share four anatomical characteristics. 1. mammary glands - to produce milk 2. hair - to retain heat
Slide 2 of 12 3. a middle ear - with three bones to hear higher-pitched sounds 4. chewing jaw - to break up food quicker A set of adaptations in the mammalian jaw makes chewing possible.
secondary palate closes off air passages muscles move jaw side-to-side Slide 4 of 12
Ruminants special group of herbivores that have compartmentalized stomachs rumen (contains many microorganisms) reticulum omasum (grinds the food and absorbs water) abomasum (acts like our stomach) They use rumination (re-chewing) as a way of feeding.
A fistula is a hole connecting the animals rumen with its exterior. It is a useful way of accessing and manipulating rumen content Feeding Some mammals have the cecum which is similar
to the rumen but found by the intestines. Slide 1 of 12 Monotremes
Placentals Marsupials - Oviparous Slide 6 of 12
Monotremes Incubate 12 days Transitional species Male has a venomous spur on hind limb - Viviparous - live birth
Slide 7 of 12 Marsupials Pouched mammals Birth to tiny embryo Embryo attaches to mothers
nipple to complete development Marsupials give birth to live young that grow to maturity inside a pouch called marsupium. opossum
kangaroo wombat koala Slide 8 of 12 Placental Mammals Placenta nourishes
embryo Long gestation period 22 months for elephant Most successful group of mammals Placental Mammals
Placental Mammals Placental mammals are named for an internal structure called the placenta, which forms when the embryo's tissues join with tissues from within the mother's body. Copyright Pearson Prentice Hall Placental Mammals
Competitive advantage over monotremes and marsupials http://ghs-montage.gwd50.k12.sc.u s/SAFARI/montage/play.php?fromp age=play&keyindex=3663&location =local
Better nutrition from placenta Less vulnerable to predators More advanced at birth Evolution of Placenta from Amniotic Egg
Reptile Mammal Chorion Form Oxygen placenta from airto get oxygen & food from mothers blood
Amnion Provides private pond Yolk sac Sac Temporarily Food for embryo make RBCs
Allantois Form Store umbilical urinary waste cord Eutherians give birth to live young that have
completed fetal development. most familiar mammals humans Eutherians filled many niches after the extinction of the dinosaurs.
Placental Mammals Gestation periods vary among mammals. This is how long the embryo stays inside the mothers body Mice -21 days, elephants22 months, Humans 9- months Gestation period increases with the size of the adult and the degree to which the newborns
and developed. Mammal Classification 19 major orders Over 4,000 species About half are rodents Migration
Some terrestrial mammals, like caribou and bison, migrate twice annually between summer and winter ranges. Migration Migration is more common among
oceanic whales & seals. Horns & Antlers Horns, like those of sheep & cattle, are hollow sheaths of keratinized epidermis with a core of bone.
Found in both sexes, grow continuously, are not shed. Horns & Antlers Antlers, like those of deer, are branched and composed of solid bone. During growth, they
have a highly vascular soft skin called velvet covering them. Usually only males have antlers. Both sexes of Caribou have antlers.
Territoriality Many mammals defend a territory that includes resources such as food, shelter, or mates that is defended from others usually of the same species (conspecifics) those that would utilize the same resources. Territoriality
A mammal usually has a larger, undefended home range that may overlap with the home range of conspecifics. Slide 9 of 12 Order Monotremata Lays eggs
Young lick milk from mothers fur Order Marsupiallia Pouch Order Xenarthra
Toothless or peg like teeth Order Lagomorpha Four upper incisors Hind legs adapted for jumping
Order Rodentia Chisel-like incisor teeth 40% of all mammals Order Primates
Opposable thumb Binocular vision Fingernails usually Mammary glands reduced to one thoracic
pair http://ghs-montage.gwd50.k12. sc.us/SAFARI/montage/play.php ?keyindex=3653 Primates The mammalian order Primates include:
Lemurs, tarsiers, monkeys, and apes Humans are members of the ape group. Primates Most primates have hands and feet adapted for grasping. Primates also have:
A large brain and short jaws. Forward-looking eyes close together on the face, providing depth perception. Well-developed parental care and complex social behavior. A fully opposable thumb. Living Primates
There are three main groups of living primates: The lemurs of Madagascar and the lorises and pottos of tropical Africa and southern Asia form
one group. Living Primates The tarsiers of Southeast Asia. Living Primates The anthropoids, which
include monkeys and hominids worldwide. Primate Evolution The oldest known anthropoid fossils are about 45 million years old.
Indicate that tarsiers are more closely related to anthropoids. Primate Evolution The fossil record indicates that monkeys first appeared in the New
World (South America) during the Oligocene (~36 mya). The first monkeys evolved in the Old World (Africa and Asia) about 40 mya.
Primate Evolution New World and Old World monkeys underwent separate adaptive radiations during their many millions of years of separation. Primate Evolution The other group of
anthropoids, the hominoids, consists of primates informally called apes. Hominoids diverged from Old World monkeys about 2025 million years ago.
Primate Evolution African apes chimpanzees & gorillas have been moved into the family Hominidae to more accurately reflect relatedness. So, now, humans, chimps and gorillas are hominids.
Many researchers advocate placing them in the genus Homo as well. Derived Characters of Hominids A number of characters distinguish humans from other hominoids: Upright posture and bipedal locomotion Larger brains
Language capabilities Symbolic thought The manufacture and use of complex tools Shortened jaw Order Insectivora Order Chiroptera
Flying mammals
Sharp-snout Small Burrow underground Eat insects http://ghs-montage.gwd50.k12.sc.us/SAFARI/montage/play.php?ke
yindex=3472&chapterskeyindex=-1&keyconceptskeyindex=-1&scen eclipskeyindex=-1&location=local Order Carnivora Order Pinnipedia Large canine teeth Limbs modified for Teeth adapted to shear swimming
flesh Marine carnivores http://ghs-montage.gwd 50.k12.sc.us/SAFARI/mo ntage/play.php?keyindex =3594 Order
Artiodactyla Two or four toes Order Perissodactyla One or three toes Order Cetacea
Front limbs modified into flippers No hind limbs Marine
Order Sirenia Manatee Marine Herbivore No tusk
Order Proboscidea Tusks Largest living land mammal Placental Orders
Xenarthra anteaters, armadillos and sloths Lagomoropha rabbits
Rodentia rats and mice Primates us, monkeys and apes Chiroptera bats Insectivora shrews, hedgehogs and moles Carnivora dogs, cats, bears, Pinnipedia - otters and seals Artiodactyla ungulated (hooves) (even) deer, giraffes, pigs Perissodactyla - ungulated (odd) cows, horses, and rhinos
Cetacea whales and dolphins Sirenia manatees Proboscidea - elephants The End
