Spores are tiny, light and have a durable protective wall. They are easily dispersed by wind and water. The first know spores are 430 million years old. Most early plants are preserved as a thin carbon film in the rocks. These specimens, however, have retained their three dimensional structure.
Vascular cells are clearly visible when the stems are examined under a microscope.
Plants help to break down rocks and contribute their own decaying remains to create rich, productive soils. Before plants invaded the land, there was no soil as we know it. Plants changed the pattern of erosion by binding soil with their roots and retaining runoff water. Land plants alter atmospheric conditions by giving off oxygen and absorbing carbon dioxide. This document was prepared by Wayne Hortensius, Calgary, Alberta, Canada for the Royal Tyrrell Museum Cooperating Society.