Life of the Late Paleozoic Era

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Lecture 19 Life of the Late Paleozoic Era
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Historical Geology
Late Paleozoic Life
I Late Paleozoic Marine Communities II Late
Paleozoic Land Communities A) Plants 1) Spore-b
earing Plants 2) Gymnosperms B) Metazoans
(Animals) 1) Reptiles 2) The Amniotic
Egg III The Permian Mass Extinction
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Late Paleozoic Life
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Historical Geology
Late Paleozoic Marine Communities
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Historical Geology
Late Paleozoic Marine Communities

• Phylum Echinodermata
• Class Crinoidea

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Historical Geology
Late Paleozoic Marine Communities

• Phylum Echinodermata
• Class Blastoidea

Petremites
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Historical Geology
Historical Geology
Late Paleozoic Marine Communities
Productid Brachiopods

• index fossils for the Permian period
• spines were attached at raised bumps found on
  fossil shells

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Historical Geology
Late Paleozoic Marine Communities Fusulinids

• Kingdom Protista

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Historical Geology
Late Paleozoic Life Plants
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Historical Geology
Late Paleozoic Land Flora
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Historical Geology
Late Paleozoic Land Flora Lycopsids
Lepidodendron stem
Lepidostrobus cone
Baragwanathia
Lycopodium
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Historical Geology
Late Paleozoic Land Flora Sphenopsids

• Sphenopsids were segmented spore plants that also
  achieved giant sizes
• Calamites, Annularia
• Modern sphenopsids include horsetails

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Historical Geology
Late Paleozoic Land Flora The Advantage of Seeds
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Historical Geology
Late Paleozoic Land Flora Seed Ferns
Glossopteris
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Historical Geology
Late Paleozoic Life Insects

• Insects had appeared in Devonian time
• Wingless forms
• Insects underwent evolutionary radiation in
  Carboniferous time
• Primitive winged forms (dragon flies)
• Forms with folding wings

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Historical Geology
Late Paleozoic Life The Amniotic Egg
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Historical Geology
Late Paleozoic Life Reptile Evolution
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Historical Geology
Late Paleozoic Life Reptile Evolution
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Historical Geology
Late Paleozoic Life Reptile Evolution -
Pelycosaurs

• evolved from the protorothyrids during the
  Pennsylvanian
• the dominant reptile group by the Early Permian
• evolved into a diverse assemblage

The herbivore Edaphosaurus
The carnivore Dimetrodon
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Historical Geology
Late Paleozoic Life Reptile Evolution - Therapsids
Moschops
Dicynodon
diverse, mammal-like reptiles originated in the
Permian but survived into the Triassic period
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Historical Geology
Late Paleozoic Life Reptile Evolution - Therapsid
Characteristics

• small- to medium-sized animals
• displaying many mammalian features
• fewer bones in the skull due to fusion of many of
  the small skull bones
• enlargement of the lower jawbone
• differentiation of the teeth for various
  functions such as nipping, tearing, and chewing
  food
• and a more vertical position of the legs for
  greater flexibility,
• as opposed to the sideways sprawling legs in
  primitive reptiles

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Historical Geology
The Permian Mass Extinction
Losses

• Species 90-95

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Historical Geology
The Permian Mass Extinction
fusulinids
bryozoans
tabulate corals
rugose corals
porifera
brachiopods
trilobites
gastropoda
blastoidea
crinoidea
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Historical Geology
The Permian Mass Extinction

• Global Cooling (Glaciation
• Marine anoxia began in Late Permian, extended
  through Early Triassic
• Negative shift in d13C values at extinction level
  (continental and marine sections)
• Age of massive Siberian flood basalts is same as
  extinction
• Climatic warming and drying near extinction level
• Rapid Sea Level Oscillations

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Historical Geology
The Permian Mass Extinction
Deep-sea anoxic interval (Japan)
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Historical Geology
The Permian Mass Extinction
d13C isotopic shift(Italian Alps)
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Historical Geology
The Permian Mass Extinction Siberian Flood Basalts
Reichow et al. Science 2002
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Historical Geology
The Permian Mass Extinction Siberian Flood Basalts

• 45 identified lava flows
• 400m to 3,700m thick
• Volume of 1.5 to 3 106 km3
• Duration of eruptions was only 600 ky

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Historical Geology
The Permian Mass Extinction Climate Change

• Change from meandering to braided river systems
  in South Africa and Urals
• Reduction in bank-stabilizing vegetation
• Widespread charcoal horizons, desert
  sedimentation, warm indicators in paleosols
  (China, Australia, Antarctica)
• Abrupt change from Glossopteris- to
  Dicroidium-dominated floras (Australia)