Kingdom Animalia Phylum Chordata Subphylum Vertebrata Class Mammalia

1. Kingdom AnimaliaPhylum ChordataSubphylum VertebrataClass Mammalia SZ2- Students will explain the evolutionary history of animals over the geological history of Earth. Mammals evolved from synapsid reptiles

2. Primitive Chordate

3. FishTwo Chambered Heart

4. Amphibian Heart- 3 Chambers

5. Reptilian Heart – 3 chambersCrocodile- incomplete 4

6. Fig. 48.28

7. Synapsids • Animals with one skull opening behind eye socket • Located in the temporal region

8. Pelycosaurs • Synapsid reptiles from Pennsylvanian and Permian • 300-245 MYA • Body close to ground • Legs away from body • Canine like teeth Dimetron

9. Therapsids • Before dinosaurs • Evidence suggests Mammals evolved from therapsids • Body raised off the ground • Limbs more under the body • Teeth differentiated into 3 types Lystrosaurus

10. Cynodonts “dog tooth” • Lumbar ribs reduced or absent • Well developed secondary palate • Lower jaw reduced to one bone Thrinaxodon Cynognathus

11. Transitional FossilThrinaxodon 250-245 mya Body divided into lumbar and thoracic regions

12. Transitional FossilCynognathus 245-230 mya May have been endothermic and gave birth to live young Smaller than a wolf

13. Molars, hair, glands Reduced ribs, 1 jaw bone Limbs under body Canine like teeth Cladogram of Synapsids Cynodonts Mammals Therapsids Pelycosaurs Synapsid reptiles

14. Early Mammals • Triassic • 220 MYA • Small • Hair • Mammary glands • Skin glands • Molar teeth Megazostrodon

15. Repenomamus robustusAte Dinosaurs

16. Kingdom Animalia • Phylum Chordata • Class Mammalia • Have fur/hair • mammary glands • Viviparous- Give birth to live young (except monotremes) • Length of time in uterus - gestation period • Extended parental care • 4 chambered heart • endothermic

17. Mammalian Anatomical Adaptations • Muscular Diaphragm • Specialized teeth • Seven cervical(neck)vertebrae • Outer ear • Well developed brain- Largest cerebrum • Sweat glands • 7. Diphyodont teeth • Two sets • 8. Heterodont teeth • Different shapes and functions

18. Basic Mammal

19. Lion

20. Rhinoceros

21. Gorilla

22. Chimpanzee

23. Chimp and Human

24. Bat

25. Same bones, different stance

27. Incissors

28. Canine

29. Premolars

30. Molars

31. Mammal Circulation

32. Fig. 31.12

34. Monotremes • Lay eggs • Incubate 12 days • Lick milk from mothers fur • Transitional species

35. Marsupials • Pouched mammals • Birth to tiny embryo • Embryo attaches to mother’s nipple to complete development

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

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

38. Marsupials and Monotremes in Australia • Triassic Period • Mammals evolved • Pangea • Jurassic Period • Monotremes and marsupials migrated to southern pangea • Cretaceous Period • Pangea breaks up

39. 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 Evolution of Placenta from Amniotic Egg

41. Mammal Classification • 14 major orders • Over 4,000 species • About half are rodents

42. Order Monotremata • Lays eggs • Young lick milk from mothers fur

43. Order Marsupiallia • Pouch

44. Placental: Order Insectivora • Sharp-snout • Small • Burrow underground • Eat insects

45. Order Chiroptera • Only Flying mammals • Elongated fingers • Echolocation • Ex. bats Importance- • Seed dispersal • Pollination • Control insects

46. Echolocation

47. Smallest Mammal • Kitti’s hog-nosed Bat • Bumble bee size • 1.5 grams

48. Order Xenarthra • Toothless or peg like teeth

49. Order Carnivora • Large canine teeth • Teeth adapted to shear flesh

50. Order Rodentia • Chisel-like incisor teeth • Continuously grow • Largest order