Dinosaurs and Extinct Ecosystems

WARNING: this lecture contains explicit material of a geological nature. Anyone who is clueless about the geological timescale should visit [ES Times scale] or [this site]


Dinosaurs and the History of Life - Paul Olsen

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PREHISTORIC BIOMES

• Continents different
• Atmosphere different, lots of CO₂
• Climate different, but global patterns the same
  • no glaciers
  • sea-level higher
• Biota different
  
  
• BIOMES Similar maps [Rees*]
  Desert [+], Woodland, Forest
  Tundra(?)/ Polar Forest (Extinct)

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PALEOZOIC (age of fishes)

• Three Ice Ages 700, 450, 300, million years ago
  Edicarian Fauna
  
• All life in ocean until 500 million years ago
  • Trilobites
  • Invasion of Land
    • plants 500 Ma
    • animals 400 Ma [r]
  
  Permian/Triassic mass extinction 95% marine 70% land spp. extinct
      evolutionary - "Reset"

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MESOZOIC (age of dinosaurs)


• No Polar Ice-sheets
• Epicontinental seas
  • Gulf of Mexico - Arctic Sea
  • Tucson Sea
  • Marine & Freshwater

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MESOZOIC BIOMES

• Land Plants
• Land Animals
• Marine Organisms

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Land Plants Diorama


• Conifers (Araucaria, Ginkgo)
• Cycads
• Ferns spores
• Earliest Flowering Plants pollen
  Cladogram

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Land Animals phylogeny

• Dinosaur *cladogram* cf. Hominids Domaines
  • Bird-hipped Dinosaurs Orniticians
    
    • Stegosaurs
    • Ceratopsians
  • Lizard-hipped Dinosaurs Sauriscians
    • Sauropods (Ultrasaur)
    • Theropods (Tyrannosaurus rex) diorama
  • Pterosaurs [+] [Qtz]
  • Earliest Mammals

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Marine Organisms diorama

• Boney Fish (Teleost) begin to expand in Jurassic
• Plesiosaurs
• Icthyosaurs - convergent with Dolphins, Whales
• Bisbee Fm. Cretaceous, S. Az
• Permian Reef West Texas

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K-T Extinction [+]

Causes
• Impact *Map
• Volcanism D. McLean

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Cenozoic (age of mammals)

• diversification of mammals
• diversification of birds
• diversification of flowering plants


• Cooling and drying last 35 million years [Temp]
  
  • Biomes Expand
    + Tundra
    + Boreal
    + Grassland
    + Deserts
  • Mass Extinction 13,000 years ago

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