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Cambrian Periods

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  • 2 April 2020
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🔲🔲🔲PHANEROZOIC EON 540 to present

🔴PALEOZOIC ERA 540-248

ALL LIFE WAS IN THE SEA

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🔵CAMBRIAN PERIOD 540

Cambrian (Cambria, Latin name for Wales)

Lower Cambrian

Middle Cambrian

Upper Cambrian Invertebrate sea life proliferating during this and the following period

The Cambrian “explosion” and the Burgess Shale)

🔹Arthropods crustaceans arachnids insects millipedes etc 

1m descr species 3/4 +of all living org and poss 10m undescr

Trilobites were the dominant species 

🔴🔹INVERTEBRATES

⏰540 🔴🔹Arthropods

⏰530 🔴🔹FISH 

🔴🔹AMPHIBIANS

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🔵ORDOVICIAN PERIOD 500

Ordovician (Latin Ordovices, people of early Britain)

445 Lower Ordovician

Upper Ordovician Diverse marine life, including vertebrates; vascular plants

⏰475 Land plants 

⏰470 algae-like Plants

⏰470 The colonisation of the land by early plants was a key step in evolution, for life to diversify across  planet.

MASS EXTINCTION 

🔷 ICE AGE LASTING 500,000 YEARS

The first jawed vertebrates probably developed during the late Ordovician period.

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🔵SILURIAN PERIOD 445 To 415

Extensive seas reefs as new ecosystems

Silurian (Latin Silures, people of early Wales)

Lower Silurian 428

Upper Silurian Coral reefs; giant scorpions; first jawed fish

🔹Bony fish appear and 🔹plants grow on
Silurian: the Chondrichthyes (or cartilaginous fish) and the Osteichthyes (or bony fish). The bony fish evolved into two separate groups: the Actinopterygii (or ray-finned fish) and Sarcopterygii (which includes the lobe-finned fish).
🔹420 mya + 🔹Arachnids
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