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THE PALAEOZOIC ERA



THE PALAEOZOIC ERA (540 mya - 245 mya)
This is divided into six periods namely:
         
Permian    (about 286  -  245  mya)

Carboniferous    (about 360  -  286   mya) - First coal appeared

Devonian      (about 408  -  360  mya) – This is the age of fish

Silurian    (about 438  -  408  mya)

Ordovician  (about 505  -  438  mya) - This is the age of Graptolites


Cambrian    (about 540  -  505  mya) – This is the age of trilobites. More lives
emerged on Earth in this Period

ACTIVITIES IN THE CAMBRIAN PERIOD
          Sea transgression
          Mild climate
         
          Shelled Marine invertebrates appeared

Brachiopods, sponges, Trilobites, Gastropods, echinoderms, radiolarians, 
appeared
          Floating, Swimming, crawling, clinging and burrowing sea animals appeared
Also evident were: sea cucumbers, starfish, jelly fish, and water scorpions
Plants in existence were only algae (land plants were absent)

THE  ORDOVICIAN PERIOD

ACTIVITIES IN THE ORDOVICIAN PERIOD

Regression of shallow seas

Mild climate

First vertebrates emerged (jawless fishes) while invertebrates dominated

Southern Continents formed a single land mass known as Gondwana Land

First fungi emerged

Marked by high sea levels rise resulting in transgression

Mollusks, cephalopods, crustaceans, corals, bryozoans, graptolites, trilobites, brachiopods and echinoderms, were present and dominated the marine environment.


THE SILURIAN PERIOD

ACTIVITIES IN THE SILURIAN PERIOD
Shell-forming sea animals were in abundance

Vascular Plants appeared on earth

Continents were flooded and flat

Mild climate with stable and warm temperature

Land scorpions, eurypterids and Sea lilies, were predominant

Arthropods dominated the continent

Evolution of modern group of Algae and Fungi

Mass extinction of marine organisms


THE DEVONIAN PERIOD

ACTIVITIES IN THE DEVONIAN PERIOD
Migration of Fishes into the open seas

Folding and mountain-building activities took place

Violent volcanic eruptions and crustal movements

Greater percentage of the land was submerged

Appearance of amphibians and Lunged fishes. This is the age of fishes, rays and sharks

Primitive vascular plants went into extinction while modern day seed producing vascular plants appeared


THE CARBONIFEROUS PERIOD

ACTIVITIES IN THE CARBONIFEROUS PERIOD
Strictly known for coal deposits, Grit stones, and lime stones

Earth experienced highest  atmospheric oxygen levels ever seen on earth

Prominenet fauna were the winged insects

First land vertebrates appeared

Sea invertebrates like Corals, Crinoids, Bryozoans, Foraminifers, Brachiopods, Cephalopods, and Blastoids were in dominance

First Reptiles laid eggs with shells


Prominent flora was Sigillaria


THE PERMIAN PERIOD

ACTIVITIES IN THE PERMIAN PERIOD
Is known for worldwide continental uplift and orogenic movements.
           
Land masses amalgamated into the super continent (Pangaea) - thereby creating the Appalachians.
           

            Palaezoic Plants and invertebrates went into extinction
         
          Extinction of all Trilobites, Blastoids and Graptolites went into extinction

Mass extinctions occurred in this period
           
            Spiriferid brachiopods, ammonoids, foraminifers and bivalves were prevalent

          Cone-bearing Gymnosperms appeared.


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