History of life Cont The Phanerozoic Eon

1
History of life Cont The Phanerozoic Eon

• Paleozoic Era "time of ancient life" (544 and
  245 mya)
• spread of animals with hard preservable parts
  such as shells and exoskeletons.

2
The Paleozoic Era

• Cambrian
• Ordovician
• Silurian
• Devonian
• Carboniferous
• Mississippian
• Pennsylvanian
• Permian

3
Cambrian Period 550 505 mya

• Cambrian Explosion sudden appearance of a
  stupendous array of animal life, most not closely
  related to modern forms.
• The Burgess Shale best fossil assemblage
  showing cambrian explosion.
• Ancestors of almost all major groups of life
  developed.
• Trilobites primitive ex of exoskeleton -

4
End of Cambrian Period

• Glaciation in parts of the world
• ended in the greatest mass extinction in world
  history.
• nearly 96 of all marine species went extinct.
• Unknown cause

5
Ordovocian Period - 505 to 440 mya

• Following the extinctions at the close of the
  cambrian period, diversification occurred among
  the survivors.
• Corals become dominant reef-building animals -
  (How old are our coral reefs then)?
• First land plants.
• First fish

6
The Silurian period 440 410 mya

• Eukaryotic life colonized terrestrial
  environments.
• adaptive radiation The development of a
  variety of species from a single ancestral form
• Major flooding of continents as glaciers melt
• Vascular plants (transport tissue allowed for
  height

7
Crinoids common in midwest

• stems were so common in some areas of the U.S.
  midwest that native peoples used them as a form
  of currency.
• significant elements of the marine fauna until
  they nearly went extinct at the close of the
  Permian period.
• Echinoderms (same group as starfish sand
  dollars).

8
Devonian period 410 to 360 mya

• diversification of life on land,
• first terrestrial vertebrates, the amphibians
  (frogs)
• first forests of trees
• Invertebrates such as crinoids, coral, and
  brachiopods thrived in shallow seas
• Brachiopods primitive clam-like animals

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Devonian Rhynie Chert

• Scotland - groups of early vascular land plants
  have been discovered in excellent condition in
  specimens where silicification of the plants
  occurred while they were still alive and growing.
• minute detail preserved showing reproduction
• diverse fossils of fungi

10
Devonian cont

• Ferns
• New forms of arthopods
• Global cooling
• Devonian extinction of crinoids, most coral,
  triolobites, primitive fish

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The Carboniferous period 360 to 286 mya

• Coal laid down - Swamps
• Known in North America as the Mississippian
  period and the Pennsylvanian period due to
  receeding seas
• Both Mississippian Pennsylvanian in IL

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Carboniferous cont

• Sharks, bony fish (I.e. blue-gill, perch)
• Gymnosperms (pine trees)
• Amphibians, reptiles
• insects
• Glaciation stopped swamp creation no more coal
  forming

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The Permian period 286 to 245 - mya

• Reptiles gaining dominance
• Another mass extintion
• 90 of all species eliminated
• Cleared the way for the dinosaur age
• Pangea

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The Mesozoic Era 245 65 mya

• Triassic period
• Jurassic period
• Cretaceous period

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Triassic Period 245-208 mya

• Octopus
• Ginko
• Iythosaurus marine dinosaur
• Crocodiles, Modern turtles
• Gondwana in the south (composed of the future
  continents of South America, Africa, India,
  Antarctica, and Australia) and Laurasia in the
  north (Asia and North America).

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Jurassic period 208 to 146 mya

• Dinosaurs
• Atlantic ocean formed
• New coral reefs emerged
• New plant species Angiosperms
• Swimming, walking, flying reptiles
• Giant reptiles

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Jurassic cont

• Archaeopteryx, once considered the first bird.
  The fossil is from the Solnhoefen Limestone
  (Jurassic) of Germany.
• China bird-reptile fossils support

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Cretaceous period 144 to 65 mya

• Temperate climate
• Ended with mass extinction of dinosaurs and much
  other life
• Current theory asteroids cooling climate
  -Chicxulub in Yucatan, Mexico

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Cenozoic Era 65 mya to present

• Age of mammals birds
• Glaciation alters species
• 7 continents form