Plants Come Ashore

450 million years
or 110 meters to today

Geolo­gi­cal era: Paleo­zoic / Ordovician

The first plants and insects conquer the land and many new species emerge. A tropi­cal climate prevails, but the plants funda­ment­ally change it: they bind carbon dioxide (a green­house gas) from the atmo­s­phere, the tempe­ra­ture on earth drops. At the same time, the oxygen content of the atmo­s­phere incre­a­ses. The chemi­stry of the sea is also chan­ging. The large conti­nent of Gond­wana is drif­ting over the South Pole. All these factors toge­ther trig­ger the second major extinc­tion of species in the history of the Earth.

The super­con­ti­nent Gond­wana forms a large land mass in the southern hemi­s­phere. Further north, Lauren­tia and Baltica approach each other. Large parts of the conti­nents are initi­ally cove­red by shal­low warm seas. Howe­ver, the drop in tempe­ra­ture caused by plant meta­bo­lism leads to a new ice age.

Comments are closed.