1. Precambrian Eukaryotes Acritarchs Ediacaran Vendian

2. Acritarchs Cysts of unicellular eukaroytes, perhaps algae or egg cases of multicellular orgs. 1800 my through Devonian

3. Ediacaran 600 my-545 my Soft-bodied Many organisms of uncertain affinity

4. Possible annelids, cnidarians (coral relatives)

5. Possible mollusc? Probable cnidarian

6. Total mysteries

7. Vendian “little shellies” Right at Cambrian boundary

8. Phanerozoic Life, Part I. 1.Cambrian, Paleozoic and Modern Faunas slides 2.Phanerozoic Aquarium project: with your partners, go through your Aquarium pages. Identify each organism using your handouts: Invertebrates, Fish, Tetrapods 3.Time Travel Submarine

9. Trilobites: Extinct arthropods (like lobsters or shrimp but with calcite skeleton) Cambrian

11. Lingulate brachiopods

12. Strange echinoderms

13. Sponge reef

14. Burgess Shale Middle Cambrian Excellent preservation of soft-bodied orgs. 5 kinds of arthropods (only 3 kinds today) First vertebrate Mysterious critters

16. Cambrian Smallish Skeletons (if any) of phosphate or thin CaCO3 Live on or near ocean floor Sponges, trilobites, early molluscs, echinoderms, lingulate brachiopods

17. Why the Cambrian explosion in diversity? Proterozoic glaciation Atmospheric oxygen Proterozoic rifting Changes in ocean nutrients Extinction of cyanobacteria Evolution of predators

18. Ordovician Brachiopods (articulate)

19. Bryozoans

20. Crinoids (echinoderms)

21. Cephalopods

22. Corals

23. Graptolites

24. Ordovician invertebrates More robust skeletons Calcite skeletons Taller, deeper (take up more ecological space) The Paleozoic fauna appears: rhynchenelliform brachiopods, bryozoans, crinoids/blastoids, primitive cephalopods, graptolites, rugose/tabulate corals

26. Middle-Late Paleozoic

27. Increasing height, increasing depth Increasing diversity New organisms –Eurypterids (giant sea scorpions) Fish/amphibians

28. Eurypterid

29. Fish

30. Jawless (bony plates on outside) Ostracoderms

31. Armored: Acanthodians & Placoderms

32. Chondrichthyes:

33. Osteichthyes:

34. Lobe-finned fish

35. Forerunners of quadrapeds

36. Mesozoic Life Oceans - a whole new crew The Modern Fauna –Mollusks –Crustaceans –Echinoids –Fish

37. Molluscs Bivalves Gastropods

38. Crustaceans

39. Echinoids

40. Mesozoic Life Oceans - a whole new crew The Modern Fauna –Mollusks –Crustaceans –Echinoids –Fish Plus marine reptiles and ammonites

41. Marine reptiles

42. Ammonites

43. Cenozoic Oceans Like Mesozoic: Modern Fauna Minus marine reptiles and ammonites Plus whales and marine mammals

44. Phanerozoic Life, Pt. II 1.Find your Phanerozoic Terrarium pages. 2.As we go through the Powerpoint slides, find organisms in the appropriate time period. 3.Safari Through Time 4.Extinction

45. Evolution of Tetrapods Arise from sarcopterygians (lobe-finned fish) Amphibianish creatures Reptiles (to birds) Mammals

46. Tiktaalik - recent transitional find

47. Amphibians

48. Adaptations for life on land Breathe! Locomotion Avoid dessication Reproduction - amniotic egg allows longer development (no swimming larvae) –Leathery covering or eggshell –Larger size of egg –Larger yolk

49. Adaptations for life on land: plants Avoid dessication – thicker outsides Reproduction – –Fancy fertilization methods, seeds –Marine plants release gametes into water More complicated dispersal mechanisms for young

50. Reptiles Anapsids: turtles and their ancestors Synapsids: pre-mammals & mammals

51. Synapsids

52. Therapsids: immediate forerunners of mammals

53. Reptiles Anapsids: turtles and their ancestors Synapsids: pre-mammals & mammals Diapsids: Rest of reptiles –Marine reptiles –Snakes, lizards –Pterosaurs –Crocodilians –Dinosaurs and birds

54. Diapsids Pterosaurs Marine reptiles Crocodiles

55. Marine reptiles

56. Diapsids Dinosaurs Birds

57. What were dinosaurs like? At your table, address one of these questions: –How did dinosaurs stand? Were they capable of fast movement? –Were dinosaurs social animals? –Were dinos warm-blooded? How do you know?

58. Brontosaurus, 1953 Apatosaurus, 2007

59. Bone strength of ceratopsians could sustain a 35mph gallop

60. T. rex had weak leg bones, delicate skull: Probably walking, not running Maybe scavenger?

61. Maiasaurs built nests in a large nesting colony, each a mom’s length apart. Nests have no broken egg shells in them, so mom cleaned them out. Babies may have been incapable of walking, like baby birds, so required care Maternal care

62. Bone beds may represent mass mortality of a herd - for example, trying to ford a river in flood, just like caribou and wildebeest disasters of recent years. Herding

63. Trackways Some trackways have little footprints on the inside, suggesting a herd structure like elephants, where the babies are protected by the adults on the outside

64. Pack Hunting Popular idea, not much evidence: One specimen of multiple raptors with prey Large optic lobes, used in reptiles for higher brain functions

65. Warm-bloodedness Predator-prey ratios Thermal inertia Haversian canals O-18 isotopic ratio

66. Dino bone Tortoise bone

67. O-18 to O-16 ratio varies with: Season Internal temperature Cold blooded animals have growth rings and large O-18 variability. Warm-blooded animals have no growth rings, uniform O- 18 levels

68. Mammal evolution Permian: Dimetrodon-like synapsids Triassic: modern mammals appear Oligocene: giant mammals Pleistocene: megafauna

69. Mass Extinction Causes Coincidence: lots of organisms happened to die at the same time. Can be ruled out statistically.

70. Mass Extinction Causes Coincidence Physical causes: changes in climate, salinity, living space, etc.

71. Mass Extinction Causes Coincidence Physical causes Biological causes: competition, predation

72. Mass Extinction Causes Coincidence Physical causes Biological causes Catastrophe: impact, volcanoes

73. Permo-Triassic extinction Over 90% of life dies, so definitely real

74. Permo-Triassic extinction Over 90% of life dies, so definitely real Continental configuration and regression –Reduced continental shelf space –Glaciation –Severe climate

75. Permo-Triassic extinction Over 90% of life dies, so definitely real Continental configuration and regression Appearance of biological “bulldozers”: –Shallow burrowers –Earlier life was immobile bottom dwellers (brachiopods, bryozoans, crinoids, etc.)

76. Permo-Triassic extinction Over 90% of life dies, so definitely real Continental configuration and regression Appearance of biological “bulldozers” Catastrophe: –Impact? Probably not

77. Permo-Triassic extinction Over 90% of life dies, so definitely real Continental configuration and regression Appearance of biological “bulldozers” Catastrophe: –Impact? Probably not –Volcanoes

78. Cretaceous-Tertiary Extinction 85% species extinction, so it’s real No big physical changes - many small continents with lots of shelf space, mild climate No big biological changes preceding the extinction, no big change in ecological structure of the oceans after the extinction

79. K/T Catastrophe Impact hypothesis Volcanic hypothesis

80. Impact hypothesis Asteroid about 10 km (6 mi.) struck, probably in Yucatan at Chicxulub

81. Impact hypothesis Asteroid about 10 km (6 mi.) struck, probably in Yucatan at Chicxulub Immediate heat shock and wildfires near impact site

82. Impact hypothesis Asteroid about 10 km (6 mi.) struck, probably in Yucatan at Chicxulub Immediate heat shock and wildfires near impact site Particulates of gypsum (Ca 2 SO 4 ) cause acid rain, killing plankton

83. Impact hypothesis Asteroid about 10 km (6 mi.) struck, probably in Yucatan at Chicxulub Immediate heat shock and wildfires near impact site Particulates of gypsum (Ca 2 SO 4 ) cause acid rain, killing plankton Particulates create clouds, block sun, killing plants

84. Impact hypothesis Asteroid about 10 km (6 mi.) struck, probably in Yucatan at Chicxulub Immediate heat shock and wildfires near impact site Particulates of gypsum (Ca 2 SO 4 ) cause acid rain, killing plankton Particulates create clouds, block sun, killing plants Temperature drops, killing organisms with no tolerance for cold

85. Evidence Crater at Chicxulub

86. Evidence Crater at Chicxulub Iridium spike Asteroids have higher iridium abundance than Earth’s crust. Iridium of Earth is mostly in the mantle and core.

87. Evidence Crater at Chicxulub Iridium spike Shocked quartz Two directions of lamellae typical of impacts

88. Evidence Crater at Chicxulub Iridium spike Shocked quartz Tektites Glass globules from melting of surface and striking object

89. Evidence Crater at Chicxulub Iridium spike Shocked quartz Tektites Soot Carbon in boundary clay from wildfires

90. Biological effects Who dies? –Planktonic orgs. –Ocean surface ecosystem –Orgs. with poor thermoregulation Who lives?

91. Biological effects Who dies? –Planktonic orgs. –Ocean surface ecosystem –Orgs. with poor thermoregulation Who lives? –Bottom dwellers who eat dead things –Orgs. with dormancy capability

92. Biological effects Who dies? –Planktonic forams –Marine reptiles –Ammonites –Dinosaurs –Birds –Non-flowering plants –Marsupials

93. Biological effects Who lives? –Bottom communities: clams, snails, crustaceans, etc. –Placental mammals –Angiosperms –Amphibians –Turtles –Insects

94. Volcanic hypothesis Huge volcanic eruption produces climatic change, acid rain Volcanoes bring up iridium BUT: –Problems demonstrating that the eruption is the right age –Basaltic eruptions produce little ash, so little climate change