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 425 million years ago

Mean atmospheric O2
 70% of modern level

Mean atmospheric CO2
 16x pre-industrial level

Mean temperature
 3C above modern level


Paleozoic Earth - First terrestrial plants: Cooksonia caledonica; Isabel Cookson - Natural History Illustration Geologic Time Scale

 Era: Paleozoic
  Period: Silurian
   Epoch: Wenlock
    Age: Homerian*


First plants

Land plants of the species Cooksonia caledonica, the only witness to a spectacular Late Silurian sunset 425 million years ago, establish a tenuous foothold on a mound of ancient lava.

Over 400 million years ago the first plants emerged from the waters and made the Earth's surface their home. They were simple plants, standing only a few inches tall, consisting of slender stalks with branches and rounded structures called sporangia. The sporangia, common to funguses and non-seed plants today, produced and contained the spores required for reproduction.

*AKA Lockportian


Copyright Walter B. Myers. All rights reserved.

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