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Precambrian Eukaryotes

Precambrian Eukaryotes. Acritarchs Ediacaran Vendian. Cysts of unicellular eukaroytes, perhaps algae or egg cases of multicellular orgs. 1800 my through Devonian. Acritarchs. Ediacaran. 600 my-545 my Soft-bodied Many organisms of uncertain affinity.

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Precambrian Eukaryotes

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  1. Precambrian Eukaryotes Acritarchs Ediacaran Vendian

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

  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. • Cambrian, Paleozoic and Modern Faunas slides • Phanerozoic Aquarium project: with your partners, go through your Aquarium pages. Identify each organism using your handouts: Invertebrates, Fish, Tetrapods • Time Travel Submarine

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

  10. Lingulate brachiopods

  11. Strange echinoderms

  12. Sponge reef

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

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

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

  16. Ordovician Brachiopods (articulate)

  17. Bryozoans

  18. Crinoids (echinoderms)

  19. Cephalopods

  20. Corals

  21. Graptolites

  22. 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

  23. Middle-Late Paleozoic

  24. Middle-Late Paleozoic • Increasing height, increasing depth • Increasing diversity • New organisms • Eurypterids (giant sea scorpions) • Fish/amphibians

  25. Eurypterid

  26. Fish

  27. Jawless (bony plates on outside)Ostracoderms

  28. Armored:Acanthodians & Placoderms

  29. Chondrichthyes:

  30. Osteichthyes:

  31. Lobe-finned fish

  32. Forerunners of quadrapeds

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

  34. Bivalves Molluscs Gastropods

  35. Crustaceans

  36. Echinoids

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

  38. Marine reptiles

  39. Ammonites

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

  41. Phanerozoic Life, Pt. II • Find your Phanerozoic Terrarium pages. • As we go through the Powerpoint slides, find organisms in the appropriate time period. • Safari Through Time • Extinction

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

  43. Tiktaalik - recent transitional find

  44. Amphibians

  45. 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

  46. 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

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

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