ERS111H5S Lecture Notes - Lecture 9: Ediacaran Biota, Grypania, Snowball Earth
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Marc Laflamme guest lecture
Archaen fossils: stromatolites
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Modern world these are rare
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Represent layers of cyanobacteria
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Use light as a guide, so they form upwards in layers
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Eventually grow into large complexes
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Stromatolites are not as common anymore because they get fed on by other
animals
3 major domains
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Bacteria
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Archaea - complex, specialized
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Eukaryota - animals, plants, fungi
Eukaryotes: increasing complexity
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Uni vs multicellular
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Prokaryote vs eukaryote
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Membrane around nucleus
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Complex organelles
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Asexual and sexual reproduction
Precambrian eukaryotes
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Grypania
Neoproterozoic
A world in flux: supercontinent rodinia
A world in flux: snowball earth
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For roughly 50 million years
Ediacara biota
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Precambrian
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Soft bodied
○Primitive animals
○Complex organisms and ecosystems
Primitive animals
Extinct organisms: rangeomorphs
• Modular, repetitive branching
• Feeding unit: lacking a mouth, gut, tentacles, or pores
• Deep and shallow water settings
• Australia, England, northern Canada
Mistaken point, newfoundland
• World heritage site
Stomatolite reefs
Animal reefs
• Organisms that built a shell and reefs
• 545 million years ago
• First time animals started to construct and dominate their ecosystems
Animal traces
• 539 million years ago
• Behaviour of animals trapped in a rock
• Digging trails and fossilized feces and mucus
Week 9: thursday
Tuesday, November 6, 2018
12:44 PM