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Live birth – except Platypus and Echidna

What is a Mammal ?. Live birth – except Platypus and Echidna. Mammary glands, hair. Warm Blooded. Fossil Evidence. Synapsid Skull. Differentiated teeth. Dentary – Squamosal jaw joint. Mammal-like Reptiles. Pelycosaurs. Therapsids. Reptile-Mammal Transition. Eozostrodon - Morganucodon.

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Live birth – except Platypus and Echidna

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  1. What is a Mammal ? Live birth – except Platypus and Echidna Mammary glands, hair Warm Blooded

  2. Fossil Evidence Synapsid Skull Differentiated teeth Dentary – Squamosal jaw joint

  3. Mammal-like Reptiles

  4. Pelycosaurs

  5. Therapsids

  6. Reptile-Mammal Transition

  7. Eozostrodon - Morganucodon

  8. Quo Vadis?

  9. Death and Destruction – Fire and Ice Mass Extinctions Late Ordovician – 440 MY – 25% families Late Devonian – 365 MY – 19% families, 70% species End Permian – 245 MY – 54% families, 96% of species End Triassic – 208 MY – 23% families End Cretaceous – 65 MY – 17% families, 85% species Lots of smaller ones “Sixth Great Extinction” - now

  10. Causes? Glaciation Impacts Methane Clathrates Volcanism Radiation Sealevel change Ecosystem dynamics

  11. Glaciation Evidence: erosion features, sediments Causes: triggers - Continent at pole Solar Constant? Greenhouse gases? Volcanic dust? Mountain uplift?

  12. Glaciation Causes: cycles Milankovitch orbital variations Wild cards: Albedo Clouds – DMS dimethylsulfides

  13. glaciers => glaciers => glaciers => glaciers => glaciers =>

  14. Sea level

  15. Impacts

  16. Louis and Walter Alvarez Iridium anomaly Shocked quartz Tektites Effects: Nuclear winter Tsunamis Fires Change in atmospheric chemistry

  17. Volcanism Flood Basalts

  18. Methane Hydrates - Clathrates Methane released by rise in temperature or drop in pressure

  19. Radiation Interstellar Gamma Ray Bursts If within 3000 ly: destroy ozone layer UV radiation damage to life acid rain from nitric oxides Estimate one should occur every 100 My Magnetic Field Reversals

  20. Self-Organized Criticality (SOC) Key Organism Concept

  21. Periodic Extinctions? Planet Nemesis?

  22. Some say the world will end in fire, Some say in ice. From what I've tasted of desire I hold with those who favor fire. But if it had to perish twice, I think I know enough of hate To say that for destruction ice Is also great And would suffice Robert Frost

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