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Thursday, 19 October 2017

Geological Time Periods : What happened in each period? Timeline



       Period + Age  
MYA = Million Years Ago



Period: Precambrian earliest period
- 1st organisms - Single celled (oxygen present)
- Later - Multi-celled organisms

Period: Cambrian 540mya
- Lots of different organisms
- Earliest animals with backbone
- Lots of carbon dioxide

Period: Ordovician 490mya
- Lots of animals without skeletons
- Early shells fish (trilobites, nautilus, sea stars, fish) 
- 1st green plants (fungi, moss) 
- End of Ice Age

Period: Silurian 443mya
1st Advanced plants
Jawed fish with amour
More shellfish 

Period: Devonian 
- 1st Ferns
- 1st fir trees with seeds
- 1st wingless insects
- 1st amphibians
- Some animals from earlier periods die out
- Moist climate cool

Period: Carboniferous 354mya
Image result for early fish- Swampy land 
- 1st "Coal forest" 
- Coal for over millions of years
- Early sharks and large trees
- 1st reptiles+Vertebrates
- Trilobites disappearance
- Glaciers Form 
- Winged insects

Period: Permian 290mya
- Land masses have formed
- Glaciers disappear meaning the weather is warmer
- Lots of Reptiles
- 1st cone bearing trees 
- Beetles and Flies appear
- Lots of life in the Oceans
- 251mya 95% life ended - Meaning they all died out

Period: Triassic 248mya
- Dinosaurs appear
- First mammals and crocodile appear
- Modern corals and fish start to appear

Period: Jurassic 206mya
- Lots of different dinosaurs 
- Ferns and cone bearing plants 
- Mammals common but small
- First birds and lizards 
-Land mass, Pangaea breaks up into Gondwanaland and Laurasia 
- High Carbon Dioxide levels

Period: Cretaceous 144mya
- Lots of new dinosaurs including Tyrannosaurs
- New types of insects
- Flowering plants appear and become plentiful
- Modern Crocodiles and Sharks
- Early birds appear
- Gondwanaland broke up
- Rocky Mountains appear
- Carbon Dioxide similar to today

Period: Paleogene 65-23mya
- Modern plants 
- Lots of different mammals 
- Dinosaurs extinct 
- Primitive Whales
- First grasses
- Rapid changes in mammals 
- Climate cools down
- Ice age begins and ends during this period 

Period: Neogene 23- 5.3mya
- Modern climate
- Modern mammals and birds
- Horses evolve from dog like animals
- Lots of grasses
- First Apes
- Southern Alps of New Zealand appear 

Period: Quaternary 1.8mya (the present)
- Anatomically modern humans
- Human stone age culture
- Ice age comes and goes
- Sahara forms from grasslands
- Humans begin agriculture
Image result for maps of gondwanaland- Stone age -  Bronze age 3300BC - Iron age 1120 BC- Industrial revoloution leads to rise in Carbon Dioxide levels