1. Class Mammalia

2. All mammals share four anatomical characteristics.
1. mammary glands - to produce milk

3. 2. hair - to retain heat

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5. 3. a middle ear - with three bones to hear higher-pitched sounds

6. 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

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9. 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.

10. A fistula is a hole connecting the animal’s rumen with its exterior
A fistula is a hole connecting the animal’s rumen with its exterior. It is a useful way of accessing and manipulating rumen content

12. Feeding…
Some mammals have the cecum which is similar to the rumen but found by the intestines.

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16. Monotremes
Marsupials
Placentals

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- Oviparous
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18. Monotremes Incubate 12 days Transitional species
Male has a venomous spur on hind limb

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- Viviparous - live birth
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20. Marsupials Pouched mammals Birth to tiny embryo
Embryo attaches to mother’s nipple to complete development

21. Marsupials give birth to live young that grow to maturity inside a pouch called marsupium.
opossum
kangaroo
wombat
koala

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23. Placental Mammals Placenta nourishes embryo Long gestation period
22 months for elephant
Most successful group of mammals

24. Copyright Pearson Prentice Hall
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

25. Placental Mammals Competitive advantage over monotremes and marsupials
Better nutrition from placenta
Less vulnerable to predators
More advanced at birth

27. Evolution of Placenta from Amniotic Egg
Reptile
Chorion
Oxygen from air
Amnion
Provides private pond
Yolk Sac
Food for embryo
Allantois
Store urinary waste
Mammal
Chorion
Form placenta to get oxygen & food from mothers blood
Amnion
Provides private pond
Yolk sac
Temporarily make RBCs
Allantois
Form umbilical cord

29. 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.

30. Placental Mammals
Gestation periods vary among mammals. This is how long the embryo stays inside the mother’s body
Mice -21 days, elephants—22 months, Humans 9- months
Gestation period increases with the size of the adult and the degree to which the newborns and developed.

31. Mammal Classification
19 major orders
Over 4,000 species
About half are rodents

32. Migration
Some terrestrial mammals, like caribou and bison, migrate twice annually between summer and winter ranges.

33. Migration
Migration is more common among oceanic whales & seals.

34. 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.

35. 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.

36. 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.

37. Territoriality
A mammal usually has a larger, undefended home range that may overlap with the home range of conspecifics.

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40. Order Marsupiallia Order Monotremata Pouch Lays eggs
Young lick milk from mothers fur
Pouch

41. Order Lagomorpha Order Xenarthra Toothless or peg like teeth
Four upper incisors
Hind legs adapted for jumping

42. Order Primates Order Rodentia Opposable thumb Binocular vision
Fingernails usually
Mammary glands reduced to one thoracic pair
Chisel-like incisor teeth
40% of all mammals

43. Primates The mammalian order Primates include:
Lemurs, tarsiers, monkeys, and apes
Humans are members of the ape group.

44. 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.

45. 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.

46. Living Primates
The tarsiers of Southeast Asia.

47. Living Primates
The anthropoids, which include monkeys and hominids worldwide.

48. Primate Evolution
The oldest known anthropoid fossils are about 45 million years old.
Indicate that tarsiers are more closely related to anthropoids.

49. 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.

50. Primate Evolution
New World and Old World monkeys underwent separate adaptive radiations during their many millions of years of separation.

51. Primate Evolution
The other group of anthropoids, the hominoids, consists of primates informally called apes.
Hominoids diverged from Old World monkeys about 20–25 million years ago.

52. 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.

53. 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

54. Order Insectivora Order Chiroptera Sharp-snout Small
Burrow underground
Eat insects
Flying mammals

55. Order Pinnipedia Order Carnivora Large canine teeth
Teeth adapted to shear flesh
Limbs modified for swimming
Marine carnivores

56. Order Perissodactyla Order Artiodactyla Two or four toes
One or three toes

57. Order Cetacea Order Sirenia Manatee Marine Herbivore No tusk
Front limbs modified into flippers
No hind limbs
Marine

59. Order Proboscidea
Tusks
Largest living land mammal

60. 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

61. The End