1. Paleozoic Era

2. Continents in late Proterozoic Eon

3. Cratons and Mobile Belts
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
a craton
and one or more mobile belts

4. Epeiric Seas
Transgressing and regressing shallow seas called epeiric seas
Common feature of most Paleozoic cratonic histories
Cause unconformities
Continental glaciation as well as plate movement caused changes in sea level

5. Four Mobile Belts
Four mobile belts formed around the margin of the North American craton during the Paleozoic
Franklin mobile belt
Cordilleran mobile belt
Ouachita mobile belt
Appalachian mobile belt
Each was the site of mountain building in response to compressional forces
convergent plate boundary
formed such mountain ranges as the Appalachians and Ouachitas

6. Paleozoic North America
Mobile belts

7. Six Major Paleozoic Continents
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

8. 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

9. Major extinctions during Paleozoic
Ordovician
Silurian
Devonian
Permian

10. Paleogeography of the World
For the Late Cambrian Period

11. 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.

12. EARTH HISTORY PALEOZOIC LIFE
What advantages do SHELLS provide?
Protection from predators
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
M&W, Fig. 21.1a
Lapworthella, Australia. 12

13. Early History—Paleozoic Era
Trilobites, sponges, brachiopods live in oceans
Cambrian Period
mya

14. Early History—Paleozoic Era
Global warming as Rodinia breaks up
Laurentia, Kazahkstan, Siberia move toward equator
Sea level rises as ice melts
Deposition of limestone common
Cambrian Period
mya

15. Early History—Paleozoic Era
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
Cambrian Period
Ordovician Period
mya

16. Early History—Paleozoic Era
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
Cambrian Period
Ordovician Period
mya

17. Paleogeography of the World
For the Late Ordovician Period

18. Early History—Paleozoic Era
Cambrian Period
Ordovician Period
Silurian Period
mya
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

19. Early History—Paleozoic Era
Cambrian Period
Ordovician Period
Silurian Period
mya
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)

20. Paleogeography of the World
For the Middle Silurian Period

21. Early History—Paleozoic Era
Devonian Period
mya
Many mountain building events
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

22. Early History—Paleozoic Era
Devonian Period
mya
Many mountain building events
Two supercontinents: Gondwana and Euramerica
Both continents slowly drift north
Map

23. Early History—Paleozoic Era
Carboniferous Period
mya
Missisippian ( mya)
Pennsylvanian ( mya)
Fish expand in oceans, many molluscs, corals, few trilobites.
Forests and swamps with seed plants on land
Winged insects
Early amphibians on land.

24. Early History—Paleozoic Era
Carboniferous Period
mya
Many episodes of mountain building
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

26. Early History—Paleozoic Era
Permian Period
mya
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)

27. Early History—Paleozoic Era
Permian Period
mya
Climate becomes dryer
Pangaea assembled, with only Chinas and Kazahkstan separated
Warming climate, dry interior of continent

28. Pangaea!