Mean atmospheric O2
Geologic Time Scale
The fossil record reveals that great forests of tree-like plants with fern-like leaves of the genus Archaeopteris covered much of the Earth 380 million years ago. The large umbrella-like fronds appear to have been optimized for gathering sunlight at the canopy level while permitting enough light to reach the shorter and younger trees. It was great forests like these that helped to draw much of the carbon dioxide out of the primeval atmosphere while releasing the oxygen we breathe today.
Copyright © Walter B. Myers. All rights reserved.
[ Home | What's New | The Graphics | Information | Site Map | ]