Paleozoic Era
Continents in late Proterozoic Eon
Cratons and Mobile Belts
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Rodinia began breaking apart sometime during the late
Proterozoic
By the beginning of the Paleozoic Era, six major continents
were present
Each continent can be divided into two major components
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a craton
and one or more mobile belts
Epeiric Seas
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Transgressing and regressing shallow seas called epeiric
seas
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Common feature of most Paleozoic cratonic histories
Cause unconformities
Continental glaciation as well as plate movement caused
changes in sea level
Four Mobile Belts
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Four mobile belts formed around the margin of the North
American craton during the Paleozoic
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Franklin mobile belt
Cordilleran mobile belt
Ouachita mobile belt
Appalachian mobile belt
Each was the site of mountain building in response to
compressional forces
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convergent plate boundary
formed such mountain ranges as the Appalachians and
Ouachitas
Paleozoic North America
• Mobile belts
Six Major Paleozoic Continents
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At the beginning of the Paleozoic, six major continents were
present
 Baltica - Russia west of the Ural Mountains and the major
part of northern Europe
 China - a complex area consisting of at least three Paleozoic
continents that were not widely separated and are here
considered to include China, Indochina, and the Malay
Peninsula
 Gondwana - Africa, Antarctica, Australia, Florida, India,
Madagascar, and parts of the Middle East and southern
Europe
Six Major Paleozoic Continents
Kazakhstan - a triangular continent centered on Kazakhstan,
but considered by some to be an extension of the Paleozoic
Siberian continent
 Laurentia - most of present North America, Greenland,
northwestern Ireland, and Scotland
 Siberia - Russia east of the Ural Mountains and Asia north of
Kazakhstan and south Mongolia
Besides these large landmasses, geologists have also identified
numerous small microcontinents and island arcs associated
with various microplates
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Major
extinctions
during
Paleozoic
Ordovician
Silurian
Devonian
Permian
Paleogeography of the World
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For the Late Cambrian Period
EARTH HISTORY PALEOZOIC LIFE
•
In the earliest part of the Cambrian, a few small (several millimeters in
size) shelly fossils are found, but then shortly afterwards life really
“takes off ” with larger animals with hard skeletons and shells.
M&W, Fig. 21.1a
M&W, Fig. 21.1c
M&W, Fig. 21.1b
Lapworthella, Australia.
An anabaritid, Northwest
Territories, Canada.
Archaeooides, Northwest
Territories, Canada.
EARTH HISTORY PALEOZOIC LIFE
• What advantages do SHELLS provide?
-Protection from predators
M&W, Fig. 21.1a
Lapworthella, Australia.
-Protection from UV light
(allowing animals to move
into shallower water)
-When the tide goes out,
shelled organisms don’t dry
out
-Shells provide structural
support for larger and
larger organisms to evolve
Early History—Paleozoic Era
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Cambrian Period
 543-490 mya
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Trilobites, sponges,
brachiopods live in oceans
Early History—Paleozoic Era
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Cambrian Period
 543-490 mya
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Global warming as Rodinia
breaks up
Laurentia, Kazahkstan,
Siberia move toward
equator
Sea level rises as ice melts
Deposition of limestone
common
Early History—Paleozoic Era
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Cambrian Period
Ordovician Period
 490-443 mya
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Trilobites, corals, algae,
brachiopods, molluscs, in
complex reef systems
First lichens and
bryophytes on land
Major extinction at end of
period due to ice age
Early History—Paleozoic Era
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Cambrian Period
Ordovician Period
 490-443 mya
Laurentia begins to collide
with Europe (mountain
building)
Gondwana moves over pole
Land is cold and barren, warm
tropical shallow marine near
equator
Ice age toward end of
Ordovician
Paleogeography of the World
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For the Late Ordovician Period
Early History—Paleozoic Era
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Cambrian Period
Ordovician Period
Silurian Period
443-417 mya
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Abundant life in ocean, coral
reefs in shallow marine near
equator
Jawless fish common
Echinoderms and molluscs
flourish, trilobites begin to
decline
First plants on land
First terrestrial arthropods
Early History—Paleozoic Era
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Cambrian Period
Ordovician Period
Silurian Period
443-417 mya
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Gondwana moves more
across south pole
Laurentia, Siberia, Baltica
move toward each other at
equator
Early Silurian glaciers melt
and sea level rises toward
end of Silurian (greenhouse
effect)
Paleogeography of the World
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For the Middle Silurian Period
Early History—Paleozoic Era
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Devonian Period
417-354 mya
Many mountain building events
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Abundant marine life
including bony fish
First sharks
First ferns on land as well as
tree-like plants
First tetrapods and first
terrestrial arthropods
Late Devonian extinction:
70% of invertebrate species
(especially marine)
Map
Early History—Paleozoic Era
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Devonian Period
417-354 mya
Many mountain building events
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Two supercontinents:
Gondwana and Euramerica
Both continents slowly drift
north
Map
Map
Early History—Paleozoic Era
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Carboniferous Period
354-290 mya
Missisippian (354-318 mya)
Pennsylvanian (318-290 mya)
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Fish expand in oceans, many
molluscs, corals, few
trilobites.
Forests and swamps with
seed plants on land
Winged insects
Early amphibians on land.
Early History—Paleozoic Era
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Carboniferous Period
354-290 mya
Many episodes of mountain
building
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Inland seas reduced due to
beginning collision of
continents to form Pangaea
Ice develops over Gondwana
due to climate change
Land dries due to changes in
glaciation and Pangaea
Early History—Paleozoic Era
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Permian Period
290-248 mya
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Life in oceans diminishes
Predatory ammonites
First vertebrate herbivores
on land.
Reptiles common on land
Many insects on land
Many gymnosperm plants
90% of marine species
experience extinction at end
of period (Pangaea, flood
basalts in Siberia, impact)
Early History—Paleozoic Era
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Permian Period
290-248 mya
Climate becomes dryer
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Pangaea assembled, with
only Chinas and Kazahkstan
separated
Warming climate, dry
interior of continent
Pangaea!