Paleobiogeography

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Paleobiogeography
Biogeography (ENVR333) Fall 2007 5 October 2006
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PaleoBiogeography

• Time Scale
• Theory of Continental Drift and Plate Tectonics
• The Breakup of Pangea
• Biogeographic Implications of a Dynamic Geography

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Geologic Time Scale
(Fig 7.1 MacDonald 2003)
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Theory of Continental Drift

• Alfred Wegener (1880-1930)
• 1915 The Origin of Continents and Oceans
• Pangea supercontinent

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Evidence for Continental Drift
Matching shapes
Glacial deposits
Similar rock types and structures
Continuity of plant and animal fossils
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Plate Tectonics
Fig 7.5 MacDonald 2003)
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Plate Tectonics
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Pangea
connectivity
200 million km2 or 40 of earths surface
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Break up of Pangea
Laurasia
Tethyan Seaway
Gondwanaland
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Break up of Pangea
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Cenozoic Changes
India rafts into Asia (45 mya)
Africa and Europe rejoin (17 mya)
Stepping Stone Islands created (15 mya)
Central American Landbridge (6mya)
Epicontinental seas disappear
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(No Transcript)
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http//www.clearlight.com/7Emhieb/WVFossils/conti
nents.html
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Biogeographic Implications
Speciation
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Biogeographic Implications
Corridors and Barriers
Great American Interchange
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Biogeographic Implications
Corridors and Barriers
12,000 ybp
Beringia
today
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Biogeographic Implications
Marine-Climate effects